/usr/share/doc/libchemps2/html/handson.html is in chemps2-doc 1.8.5-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 | <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>12. DMRG workshop (12-jul-2016): hands-on session — CheMPS2 1.8.5 (2018-01-14) documentation</title>
<link rel="stylesheet" href="_static/classic.css" type="text/css" />
<link rel="stylesheet" href="_static/pygments.css" type="text/css" />
<script type="text/javascript">
var DOCUMENTATION_OPTIONS = {
URL_ROOT: './',
VERSION: '1.8.5 (2018-01-14)',
COLLAPSE_INDEX: false,
FILE_SUFFIX: '.html',
HAS_SOURCE: true,
SOURCELINK_SUFFIX: '.txt'
};
</script>
<script type="text/javascript" src="/usr/share/javascript/jquery/jquery.js"></script>
<script type="text/javascript" src="/usr/share/javascript/underscore/underscore.js"></script>
<script type="text/javascript" src="_static/doctools.js"></script>
<script type="text/javascript" src="/usr/share/javascript/mathjax/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
<link rel="index" title="Index" href="genindex.html" />
<link rel="search" title="Search" href="search.html" />
<link rel="prev" title="11. Interfaces to psi4 and pyscf" href="interfaces.html" />
</head>
<body>
<div class="related" role="navigation" aria-label="related navigation">
<h3>Navigation</h3>
<ul>
<li class="right" style="margin-right: 10px">
<a href="genindex.html" title="General Index"
accesskey="I">index</a></li>
<li class="right" >
<a href="interfaces.html" title="11. Interfaces to psi4 and pyscf"
accesskey="P">previous</a> |</li>
<li class="nav-item nav-item-0"><a href="index.html">CheMPS2 1.8.5 (2018-01-14) documentation</a> »</li>
</ul>
</div>
<div class="document">
<div class="documentwrapper">
<div class="bodywrapper">
<div class="body" role="main">
<div class="section" id="dmrg-workshop-12-jul-2016-hands-on-session">
<span id="index-0"></span><h1>12. DMRG workshop (12-jul-2016): hands-on session<a class="headerlink" href="#dmrg-workshop-12-jul-2016-hands-on-session" title="Permalink to this headline">¶</a></h1>
<div class="section" id="introduction">
<h2>12.1. Introduction<a class="headerlink" href="#introduction" title="Permalink to this headline">¶</a></h2>
<p>The geometry of tetracene was optimized at the restricted B3LYP/6-31G* level of theory, and can be found in the file <a class="reference external" href="https://github.com/sebwouters/chemps2/raw/master/sphinx/tetracene.fcidump.in">tetracene.fcidump.in</a>:</p>
<div class="highlight-default"><div class="highlight"><pre><span></span><span class="n">memory</span> <span class="mi">28</span> <span class="n">Gb</span>
<span class="n">molecule</span> <span class="n">tetracene</span> <span class="p">{</span>
<span class="mi">0</span> <span class="mi">1</span>
<span class="n">symmetry</span> <span class="n">csz</span>
<span class="n">C</span> <span class="mf">4.888883611380</span> <span class="o">-</span><span class="mf">0.715374463486</span> <span class="o">-</span><span class="mf">0.000000000000</span>
<span class="n">C</span> <span class="mf">4.888883611380</span> <span class="mf">0.715374463486</span> <span class="mf">0.000000000000</span>
<span class="n">C</span> <span class="o">-</span><span class="mf">4.888883611380</span> <span class="o">-</span><span class="mf">0.715374463486</span> <span class="mf">0.000000000000</span>
<span class="n">C</span> <span class="o">-</span><span class="mf">4.888883611380</span> <span class="mf">0.715374463486</span> <span class="o">-</span><span class="mf">0.000000000000</span>
<span class="n">C</span> <span class="mf">3.711144499602</span> <span class="o">-</span><span class="mf">1.409316610825</span> <span class="mf">0.000000000000</span>
<span class="n">C</span> <span class="mf">3.711144499602</span> <span class="mf">1.409316610825</span> <span class="mf">0.000000000000</span>
<span class="n">C</span> <span class="o">-</span><span class="mf">3.711144499602</span> <span class="o">-</span><span class="mf">1.409316610825</span> <span class="mf">0.000000000000</span>
<span class="n">C</span> <span class="o">-</span><span class="mf">3.711144499602</span> <span class="mf">1.409316610825</span> <span class="mf">0.000000000000</span>
<span class="n">C</span> <span class="mf">2.450542389320</span> <span class="o">-</span><span class="mf">0.725895641808</span> <span class="mf">0.000000000000</span>
<span class="n">C</span> <span class="mf">2.450542389320</span> <span class="mf">0.725895641808</span> <span class="mf">0.000000000000</span>
<span class="n">C</span> <span class="o">-</span><span class="mf">2.450542389320</span> <span class="o">-</span><span class="mf">0.725895641808</span> <span class="mf">0.000000000000</span>
<span class="n">C</span> <span class="o">-</span><span class="mf">2.450542389320</span> <span class="mf">0.725895641808</span> <span class="mf">0.000000000000</span>
<span class="n">C</span> <span class="mf">1.235393613403</span> <span class="o">-</span><span class="mf">1.406341384439</span> <span class="o">-</span><span class="mf">0.000000000000</span>
<span class="n">C</span> <span class="mf">1.235393613403</span> <span class="mf">1.406341384439</span> <span class="o">-</span><span class="mf">0.000000000000</span>
<span class="n">C</span> <span class="o">-</span><span class="mf">1.235393613403</span> <span class="o">-</span><span class="mf">1.406341384439</span> <span class="mf">0.000000000000</span>
<span class="n">C</span> <span class="o">-</span><span class="mf">1.235393613403</span> <span class="mf">1.406341384439</span> <span class="o">-</span><span class="mf">0.000000000000</span>
<span class="n">C</span> <span class="mf">0.000000000000</span> <span class="o">-</span><span class="mf">0.726150477978</span> <span class="mf">0.000000000000</span>
<span class="n">C</span> <span class="o">-</span><span class="mf">0.000000000000</span> <span class="mf">0.726150477978</span> <span class="o">-</span><span class="mf">0.000000000000</span>
<span class="n">H</span> <span class="o">-</span><span class="mf">5.836431028249</span> <span class="mf">1.247257941939</span> <span class="mf">0.000000000000</span>
<span class="n">H</span> <span class="o">-</span><span class="mf">5.836431028249</span> <span class="o">-</span><span class="mf">1.247257941939</span> <span class="o">-</span><span class="mf">0.000000000000</span>
<span class="n">H</span> <span class="mf">5.836431028249</span> <span class="o">-</span><span class="mf">1.247257941939</span> <span class="mf">0.000000000000</span>
<span class="n">H</span> <span class="mf">5.836431028249</span> <span class="mf">1.247257941939</span> <span class="o">-</span><span class="mf">0.000000000000</span>
<span class="n">H</span> <span class="mf">3.708923113951</span> <span class="o">-</span><span class="mf">2.496817544333</span> <span class="mf">0.000000000000</span>
<span class="n">H</span> <span class="mf">3.708923113951</span> <span class="mf">2.496817544333</span> <span class="mf">0.000000000000</span>
<span class="n">H</span> <span class="o">-</span><span class="mf">3.708923113951</span> <span class="o">-</span><span class="mf">2.496817544333</span> <span class="o">-</span><span class="mf">0.000000000000</span>
<span class="n">H</span> <span class="o">-</span><span class="mf">3.708923113951</span> <span class="mf">2.496817544333</span> <span class="mf">0.000000000000</span>
<span class="n">H</span> <span class="mf">1.235230564126</span> <span class="o">-</span><span class="mf">2.494555353711</span> <span class="mf">0.000000000000</span>
<span class="n">H</span> <span class="mf">1.235230564126</span> <span class="mf">2.494555353711</span> <span class="mf">0.000000000000</span>
<span class="n">H</span> <span class="o">-</span><span class="mf">1.235230564126</span> <span class="mf">2.494555353711</span> <span class="mf">0.000000000000</span>
<span class="n">H</span> <span class="o">-</span><span class="mf">1.235230564126</span> <span class="o">-</span><span class="mf">2.494555353711</span> <span class="mf">0.000000000000</span>
<span class="p">}</span>
<span class="n">sys</span><span class="o">.</span><span class="n">path</span><span class="o">.</span><span class="n">insert</span><span class="p">(</span> <span class="mi">0</span><span class="p">,</span> <span class="s1">'./..'</span> <span class="p">)</span>
<span class="kn">import</span> <span class="nn">fcidump</span>
<span class="nb">set</span> <span class="n">basis</span> <span class="mi">6</span><span class="o">-</span><span class="mi">31</span><span class="n">g</span><span class="o">*</span>
<span class="nb">set</span> <span class="n">reference</span> <span class="n">rhf</span>
<span class="nb">set</span> <span class="n">scf_type</span> <span class="n">DIRECT</span>
<span class="nb">set</span> <span class="n">e_convergence</span> <span class="mf">1e-12</span>
<span class="nb">set</span> <span class="n">d_convergence</span> <span class="mf">1e-10</span>
<span class="nb">set</span> <span class="n">ints_tolerance</span> <span class="mf">0.0</span>
<span class="nb">set</span> <span class="n">fcidump</span> <span class="n">dumpfilename</span> <span class="n">tetracene</span><span class="o">.</span><span class="n">fcidump</span>
<span class="n">E</span><span class="p">,</span> <span class="n">wfn</span> <span class="o">=</span> <span class="n">energy</span><span class="p">(</span> <span class="s1">'fcidump'</span><span class="p">,</span> <span class="n">return_wfn</span><span class="o">=</span><span class="kc">True</span> <span class="p">)</span>
<span class="n">molden</span><span class="p">(</span> <span class="n">wfn</span><span class="p">,</span> <span class="s1">'tetracene.molden'</span> <span class="p">)</span>
</pre></div>
</div>
<p>The goal of this afternoon is to calculate the vertical singlet-triplet gap with DMRG(18, 18)-CASPT2/6-31G*.</p>
<p><a class="reference external" href="https://github.com/sebwouters/chemps2">chemps2</a> is a C++ library for spin-adapted DMRG calculations which can be incorporated in quantum chemistry packages. This has been done for <a class="reference external" href="http://www.psicode.org/">psi4</a>. Alternatively, the same functionality can be used with the binary, when the required matrix elements have been generated in <code class="docutils literal"><span class="pre">FCIDUMP</span></code> format. We will follow the second route this afternoon. The advantage of the latter route is that you are not tied to <a class="reference external" href="http://www.psicode.org/">psi4</a> to obtain matrix elements. In the future you can use <a class="reference external" href="http://www.molcas.org/">molcas</a>, <a class="reference external" href="https://www.molpro.net/">molpro</a>, <a class="reference external" href="http://www.daltonprogram.org/">dalton</a>… The disadvantage is that a full-rank <code class="docutils literal"><span class="pre">FCIDUMP</span></code> file is required, and that less virtual (secondary) orbitals can be used than with density-fitted DMRG-SCF and DMRG-CASPT2.</p>
<p>Please read an entire section before starting the instructions. Then you will have all the useful information you need!</p>
</div>
<div class="section" id="ugent-hpc">
<h2>12.2. UGent HPC<a class="headerlink" href="#ugent-hpc" title="Permalink to this headline">¶</a></h2>
<p>Follow the <a class="reference external" href="http://hpc.ugent.be/userwiki/index.php/User:VscConnect">instructions</a> to log in to the UGent HPC.</p>
<p>Submit an interactive job in the XYZ queue:</p>
<div class="highlight-bash"><div class="highlight"><pre><span></span>$ qsub -I -W <span class="nv">x</span><span class="o">=</span>FLAGS:ADVRES:dmrg.198 -l <span class="nv">walltime</span><span class="o">=</span><span class="m">06</span>:00:00 -l <span class="nv">nodes</span><span class="o">=</span><span class="m">1</span>:ppn<span class="o">=</span><span class="m">8</span>
</pre></div>
</div>
<p>Once you are on the node, change directory to, for example, the following folder:</p>
<div class="highlight-bash"><div class="highlight"><pre><span></span>$ <span class="nb">cd</span> <span class="nv">$VSC_SCRATCH_NODE</span>
$ mkdir dmrg_workshop
$ <span class="nb">cd</span> dmrg_workshop/
</pre></div>
</div>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">Please keep in mind that you will need about 20 GB of disk for the <code class="docutils literal"><span class="pre">FCIDUMP</span></code> file and 1 GB of disk for the <a class="reference external" href="https://github.com/sebwouters/chemps2">chemps2</a> checkpoints!</p>
</div>
</div>
<div class="section" id="fcidump-and-molden">
<h2>12.3. <code class="docutils literal"><span class="pre">FCIDUMP</span></code> and <code class="docutils literal"><span class="pre">MOLDEN</span></code><a class="headerlink" href="#fcidump-and-molden" title="Permalink to this headline">¶</a></h2>
<p>We will first use a plugin to <a class="reference external" href="http://www.psicode.org/">psi4</a> to generate the RHF matrix elements in <code class="docutils literal"><span class="pre">FCIDUMP</span></code> format, as well as the corresponding <code class="docutils literal"><span class="pre">MOLDEN</span></code> file. As said before, any other program which is able to generate these two types of files can be used as well. Load the <a class="reference external" href="http://www.psicode.org/">psi4</a> module and generate a new plugin called <code class="docutils literal"><span class="pre">fcidump</span></code>:</p>
<div class="highlight-bash"><div class="highlight"><pre><span></span>$ module load PSI4/1.0-intel-2016a-mt-Python-2.7.11
$ psi4 --new-plugin fcidump
</pre></div>
</div>
<p>Overwrite the dummy file <code class="docutils literal"><span class="pre">fcidump.cc</span></code> and compile:</p>
<div class="highlight-bash"><div class="highlight"><pre><span></span>$ <span class="nb">cd</span> fcidump/
$ rm fcidump.cc
$ wget <span class="s1">'https://github.com/sebwouters/chemps2/raw/master/integrals/psi4plugins/fcidump.cc'</span>
$ make
$ <span class="nb">cd</span> ../
</pre></div>
</div>
<p>The required <code class="docutils literal"><span class="pre">FCIDUMP</span></code> file and the corresponding <code class="docutils literal"><span class="pre">MOLDEN</span></code> file can now be generated with <a class="reference external" href="http://www.psicode.org/">psi4</a>:</p>
<div class="highlight-bash"><div class="highlight"><pre><span></span>$ wget <span class="s1">'https://github.com/sebwouters/chemps2/raw/master/sphinx/tetracene.fcidump.in'</span>
$ <span class="nv">OMP_NUM_THREADS</span><span class="o">=</span><span class="m">8</span> psi4 -n <span class="m">8</span> tetracene.fcidump.in <span class="p">&</span>
$ tail -n <span class="m">3000</span> -f tetracene.fcidump.out
$ ls -alh TETRACENE.FCIDUMP
$ ls -alh tetracene.molden
</pre></div>
</div>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">The specified symmetry group in <code class="docutils literal"><span class="pre">tetracene.fcidump.in</span></code> was <code class="docutils literal"><span class="pre">csz</span></code>, a subgroup of <code class="docutils literal"><span class="pre">d2h</span></code>. In the <code class="docutils literal"><span class="pre">csz</span></code> symmetry group, the 18 active space <span class="math">\(\pi\)</span>-orbitals can be localized to the carbon atoms. This is not the case for the <code class="docutils literal"><span class="pre">d2h</span></code> symmetry group.</p>
</div>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">While you are waiting for the <code class="docutils literal"><span class="pre">FCIDUMP</span></code> file of size 20 GB, you can already proceed with the next section.</p>
</div>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p>You can also use the precreated files from the folder <code class="docutils literal"><span class="pre">/apps/gent/tutorials/DMRG/</span></code> instead:</p>
<div class="last highlight-bash"><div class="highlight"><pre><span></span>$ ls -al /apps/gent/tutorials/DMRG/tetracene.fcidump.in
$ ls -al /apps/gent/tutorials/DMRG/tetracene.fcidump.out
$ ls -al /apps/gent/tutorials/DMRG/TETRACENE.FCIDUMP
$ ls -al /apps/gent/tutorials/DMRG/tetracene.molden
</pre></div>
</div>
</div>
</div>
<div class="section" id="basis-choice">
<h2>12.4. Basis choice<a class="headerlink" href="#basis-choice" title="Permalink to this headline">¶</a></h2>
<p>Now that you have the required matrix elements in <code class="docutils literal"><span class="pre">FCIDUMP</span></code> format and the corresponding <code class="docutils literal"><span class="pre">MOLDEN</span></code> file, we can perform calculations with <a class="reference external" href="https://github.com/sebwouters/chemps2">chemps2</a> v1.7.2. This module should have been loaded together with the <a class="reference external" href="http://www.psicode.org/">psi4</a> module. If this was not the case, you can load it with:</p>
<div class="highlight-bash"><div class="highlight"><pre><span></span>$ module load CheMPS2/1.7.2-intel-2016a
</pre></div>
</div>
<p>Study the options of the binary:</p>
<div class="highlight-bash"><div class="highlight"><pre><span></span>$ chemps2 --version
$ chemps2 --help
</pre></div>
</div>
<p>Perform each calculation in a separate folder. This way checkpoint files will not get mixed up. Create a folder <code class="docutils literal"><span class="pre">ci_input_orbs/</span></code> and in that folder an input file <code class="docutils literal"><span class="pre">ci_input_orbs.in</span></code> for <a class="reference external" href="https://github.com/sebwouters/chemps2">chemps2</a> with the following options:</p>
<ul class="simple">
<li>Target the singlet ground state</li>
<li>Use an (18, 18) active space</li>
<li>Switch off the CASPT2 calculation</li>
<li>Overwrite the tmp folder with the existing path <code class="docutils literal"><span class="pre">/local/NUMBER.master15.delcatty.gent.vsc/</span></code>, where <code class="docutils literal"><span class="pre">NUMBER</span></code> is the job number which you see with</li>
</ul>
<div class="highlight-bash"><div class="highlight"><pre><span></span>$ qstat -n
</pre></div>
</div>
<ul class="simple">
<li>Perform one DMRG-SCF iteration, which corresponds to DMRG-CI</li>
<li>The active space orbitals should be the RHF molecular orbitals (i.e. the input orbitals)</li>
<li>Use the convergence scheme</li>
</ul>
<blockquote>
<div><table border="1" class="docutils">
<colgroup>
<col width="20%" />
<col width="19%" />
<col width="18%" />
<col width="25%" />
<col width="18%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head"><span class="math">\(D_{SU(2)}\)</span></th>
<th class="head"><span class="math">\(E_{conv}\)</span></th>
<th class="head"><span class="math">\(N_{max}\)</span></th>
<th class="head"><span class="math">\(\gamma_{noise}\)</span></th>
<th class="head"><span class="math">\(r_{tol}\)</span></th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>200</td>
<td>1e-6</td>
<td>10</td>
<td>0.05</td>
<td>1e-5</td>
</tr>
<tr class="row-odd"><td>400</td>
<td>1e-6</td>
<td>10</td>
<td>0.05</td>
<td>1e-5</td>
</tr>
<tr class="row-even"><td>600</td>
<td>1e-6</td>
<td>10</td>
<td>0.05</td>
<td>1e-5</td>
</tr>
<tr class="row-odd"><td>600</td>
<td>1e-8</td>
<td>3</td>
<td>0.0</td>
<td>1e-5</td>
</tr>
<tr class="row-even"><td>400</td>
<td>1e-8</td>
<td>3</td>
<td>0.0</td>
<td>1e-5</td>
</tr>
<tr class="row-odd"><td>200</td>
<td>1e-8</td>
<td>3</td>
<td>0.0</td>
<td>1e-5</td>
</tr>
</tbody>
</table>
</div></blockquote>
<ul class="simple">
<li>Set the option <code class="docutils literal"><span class="pre">SCF_MOLDEN</span></code> to the corresponding molden file</li>
</ul>
<p>When you have created the input file, you can double check with the <a class="reference internal" href="#first-ptr-solution"><span class="std std-ref">solution</span></a>.</p>
<p>Run the calculation:</p>
<div class="highlight-bash"><div class="highlight"><pre><span></span>$ <span class="nb">cd</span> ci_input_orbs/
$ <span class="nv">OMP_NUM_THREADS</span><span class="o">=</span><span class="m">4</span> chemps2 --file<span class="o">=</span>ci_input_orbs.in <span class="p">&</span>> ci_input_orbs.out <span class="p">&</span>
$ <span class="nb">cd</span> ../
</pre></div>
</div>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p class="last">You have now only used 4 of the 8 available cores. Proceed with the instructions below while waiting for the calculation to finish.</p>
</div>
<p>Create a folder <code class="docutils literal"><span class="pre">ci_local_orbs/</span></code> and in that folder an input file <code class="docutils literal"><span class="pre">ci_local_orbs.in</span></code> for <a class="reference external" href="https://github.com/sebwouters/chemps2">chemps2</a>, which is identical to <code class="docutils literal"><span class="pre">ci_input_orbs.in</span></code>, except for the active space orbitals. These should now be localized orbitals. When you have created the input file, you can double check with the <a class="reference internal" href="#second-ptr-solution"><span class="std std-ref">solution</span></a>.</p>
<p>Run the calculation:</p>
<div class="highlight-bash"><div class="highlight"><pre><span></span>$ <span class="nb">cd</span> ci_local_orbs/
$ <span class="nv">OMP_NUM_THREADS</span><span class="o">=</span><span class="m">4</span> chemps2 --file<span class="o">=</span>ci_local_orbs.in <span class="p">&</span>> ci_local_orbs.out <span class="p">&</span>
$ <span class="nb">cd</span> ../
$ tail -n <span class="m">300</span> ci_input_orbs/ci_input_orbs.out
$ tail -n <span class="m">300</span> ci_local_orbs/ci_local_orbs.out
</pre></div>
</div>
<p>When the calculations are finished, take a look at the files</p>
<blockquote>
<div><ul class="simple">
<li><code class="docutils literal"><span class="pre">ci_input_orbs/tetracene.molden.rotated</span></code></li>
<li><code class="docutils literal"><span class="pre">ci_local_orbs/tetracene.molden.rotated</span></code></li>
</ul>
</div></blockquote>
<p>with your favourite visualization software. Do the first 18 <code class="docutils literal"><span class="pre">App</span></code> or <code class="docutils literal"><span class="pre">A"</span></code> orbitals have the desired shape? How are they ordered? Once you have formulated your own answer, you can double check with the <a class="reference internal" href="#third-ptr-solution"><span class="std std-ref">solution</span></a>.</p>
<p>Compare the energies of the last three sweep instructions as a function of <span class="math">\(D_{SU(2)}\)</span> for both calculations. Thereto you can grep for:</p>
<div class="highlight-bash"><div class="highlight"><pre><span></span>$ grep <span class="s2">"Minimum energy encountered during the last sweep"</span> ci_input_orbs/ci_input_orbs.out
$ grep <span class="s2">"Minimum energy encountered during the last sweep"</span> ci_local_orbs/ci_local_orbs.out
</pre></div>
</div>
<p>What do you observe? Can you explain it? Once you have formulated your own answer, you can double check with the <a class="reference internal" href="#fourth-ptr-solution"><span class="std std-ref">solution</span></a>.</p>
</div>
<div class="section" id="dmrg-scf">
<h2>12.5. DMRG-SCF<a class="headerlink" href="#dmrg-scf" title="Permalink to this headline">¶</a></h2>
<p>Use localized orbitals for the active space from now on. Perform the DMRG-SCF orbital optimization for the singlet and the triplet. Also put DIIS on when the update norm is smaller than 1e-2, switch <code class="docutils literal"><span class="pre">PRINT_CORR</span></code> to <code class="docutils literal"><span class="pre">TRUE</span></code>, and remove the <code class="docutils literal"><span class="pre">SCF_MOLDEN</span></code> line. Use the following convergence scheme:</p>
<blockquote>
<div><table border="1" class="docutils">
<colgroup>
<col width="20%" />
<col width="19%" />
<col width="18%" />
<col width="25%" />
<col width="18%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head"><span class="math">\(D_{SU(2)}\)</span></th>
<th class="head"><span class="math">\(E_{conv}\)</span></th>
<th class="head"><span class="math">\(N_{max}\)</span></th>
<th class="head"><span class="math">\(\gamma_{noise}\)</span></th>
<th class="head"><span class="math">\(r_{tol}\)</span></th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>250</td>
<td>1e-6</td>
<td>8</td>
<td>0.05</td>
<td>1e-5</td>
</tr>
<tr class="row-odd"><td>500</td>
<td>1e-8</td>
<td>8</td>
<td>0.05</td>
<td>1e-5</td>
</tr>
<tr class="row-even"><td>750</td>
<td>1e-10</td>
<td>8</td>
<td>0.0</td>
<td>1e-8</td>
</tr>
</tbody>
</table>
</div></blockquote>
<p>Why is the reduced virtual dimension not lowered at the end of the DMRG calculation? Why is the last <span class="math">\(r_{tol}\)</span> smaller? When you have created the input files, you can double check with the solution for the <a class="reference internal" href="#fifth-ptr-solution"><span class="std std-ref">singlet</span></a> and the <a class="reference internal" href="#sixth-ptr-solution"><span class="std std-ref">triplet</span></a>.</p>
<p>Run the calculation in separate folders:</p>
<div class="highlight-bash"><div class="highlight"><pre><span></span>$ <span class="nb">cd</span> scf_singlet/
$ <span class="nv">OMP_NUM_THREADS</span><span class="o">=</span><span class="m">4</span> chemps2 --file<span class="o">=</span>scf_singlet.in <span class="p">&</span>> scf_singlet.out <span class="p">&</span>
$ <span class="nb">cd</span> ../scf_triplet/
$ <span class="nv">OMP_NUM_THREADS</span><span class="o">=</span><span class="m">4</span> chemps2 --file<span class="o">=</span>scf_triplet.in <span class="p">&</span>> scf_triplet.out <span class="p">&</span>
$ <span class="nb">cd</span> ../
$ tail -n <span class="m">300</span> scf_singlet/scf_singlet.out
$ tail -n <span class="m">300</span> scf_triplet/scf_triplet.out
</pre></div>
</div>
<p>What is the DMRG-SCF singlet-triplet gap you obtain? Double check with the <a class="reference internal" href="#seventh-ptr-solution"><span class="std std-ref">solution</span></a>.</p>
<p>Do you see polyradical character in the natural orbital occupation numbers for the singlet and/or triplet? How can you observe this in the correlation functions? Tip: It might be interesting to read</p>
<ol class="upperalpha simple" start="10">
<li>Hachmann, J. J. Dorando, Michael Avilés and Garnet Kin-Lic Chan, <em>Journal of Chemical Physics</em> <strong>127</strong>, 134309 (2007): <a class="reference external" href="http://dx.doi.org/10.1063/1.2768362">doi link</a> or <a class="reference external" href="https://arxiv.org/abs/0707.3120">arXiv</a></li>
</ol>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p>If you are in a hurry or immediately want to start with the DMRG-CASPT2 calculations, you can also use the precreated checkpoints from the folder <code class="docutils literal"><span class="pre">/apps/gent/tutorials/DMRG/</span></code>:</p>
<div class="last highlight-bash"><div class="highlight"><pre><span></span>$ cp /apps/gent/tutorials/DMRG/CheMPS2_CASSCF.h5.singlet scf_singlet/.
$ cp /apps/gent/tutorials/DMRG/CheMPS2_CASSCF.h5.triplet scf_triplet/.
</pre></div>
</div>
</div>
</div>
<div class="section" id="dmrg-caspt2">
<h2>12.6. DMRG-CASPT2<a class="headerlink" href="#dmrg-caspt2" title="Permalink to this headline">¶</a></h2>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p>DMRG-CASPT2 checkpoints can be used when you kill a DMRG-CASPT2 calculation before it is finished, or to redo the DMRG-CASPT2 calculation with another IPEA or IMAG shift. In case you would like to use checkpoints for the DMRG-CASPT2 calculations, it is important that for subsequent runs <strong>exactly</strong> the same orbitals are used. Therefore, start from the converged DMRG-SCF checkpoint <code class="docutils literal"><span class="pre">CheMPS2_CASSCF.h5</span></code> and do the following things:</p>
<blockquote>
<div><ul class="simple">
<li>Put <code class="docutils literal"><span class="pre">SCF_DIIS_THR</span></code> to <code class="docutils literal"><span class="pre">0.0</span></code></li>
<li>Delete any checkpoints named <code class="docutils literal"><span class="pre">CheMPS2_DIIS.h5</span></code></li>
<li>Switch <code class="docutils literal"><span class="pre">SCF_ACTIVE_SPACE</span></code> to <code class="docutils literal"><span class="pre">I</span></code></li>
</ul>
</div></blockquote>
<p class="last">This ensures that for the subsequent DMRG-CASPT2 runs, <strong>exactly</strong> the orbitals from <code class="docutils literal"><span class="pre">CheMPS2_CASSCF.h5</span></code> are used.</p>
</div>
<p>How large is the singlet-triplet gap with DMRG-CASPT2 when an IPEA shift of 0.0 and an IMAG shift of 0.0 are used? Is it best to use <code class="docutils literal"><span class="pre">A</span></code> or <code class="docutils literal"><span class="pre">P</span></code> for the option <code class="docutils literal"><span class="pre">CASPT2_ORBS</span></code>, and why? In your input file, also switch on the DMRG-CASPT2 checkpoint, because later we will redo the calculation with an IPEA shift of 0.25. Use the same convergence scheme as for the DMRG-SCF calculations.</p>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p>Sometimes a larger virtual dimension can be required for DMRG-CASPT2 as compared to DMRG-SCF, because the excited wavefunctions</p>
<div class="math">
\[\left| sz, \alpha, \beta \right\rangle = \left[ \alpha \left( \hat{E}_{sz} + \hat{E}_{zs} \right) + \beta \right] \left| \Psi_0 \right\rangle\]</div>
<p class="last">are a linear combination over three matrix product states: <span class="math">\(\left| \Psi_0 \right\rangle\)</span>, <span class="math">\(\hat{E}_{sz} \left| \Psi_0 \right\rangle\)</span>, and <span class="math">\(\hat{E}_{zs} \left| \Psi_0 \right\rangle\)</span>. In practice, you should therefore check how the DMRG-CASPT2 second order energy in <a class="reference external" href="https://github.com/sebwouters/chemps2">chemps2</a> varies with <span class="math">\(D_{SU(2)}\)</span>!</p>
</div>
<p>When you have created the input files, you can double check with the solution for the <a class="reference internal" href="#eigth-ptr-solution"><span class="std std-ref">singlet</span></a> and the <a class="reference internal" href="#nineth-ptr-solution"><span class="std std-ref">triplet</span></a>.</p>
<p>Run the calculations, but please remember to copy over the converged DMRG-SCF orbitals:</p>
<div class="highlight-bash"><div class="highlight"><pre><span></span>$ <span class="nb">cd</span> pt2_singlet/
$ cp ../scf_singlet/CheMPS2_CASSCF.h5 .
$ <span class="nv">OMP_NUM_THREADS</span><span class="o">=</span><span class="m">4</span> chemps2 --file<span class="o">=</span>pt2_singlet.in <span class="p">&</span>> pt2_singlet.out <span class="p">&</span>
$ <span class="nb">cd</span> ../pt2_triplet/
$ cp ../scf_triplet/CheMPS2_CASSCF.h5 .
$ <span class="nv">OMP_NUM_THREADS</span><span class="o">=</span><span class="m">4</span> chemps2 --file<span class="o">=</span>pt2_triplet.in <span class="p">&</span>> pt2_triplet.out <span class="p">&</span>
$ <span class="nb">cd</span> ../
$ tail -n <span class="m">300</span> pt2_singlet/pt2_singlet.out
$ tail -n <span class="m">300</span> pt2_triplet/pt2_triplet.out
</pre></div>
</div>
<p>How large is the singlet-triplet gap with DMRG-CASPT2 when an IPEA shift of 0.0 and an IMAG shift of 0.0 are used?</p>
<p>And with an IPEA shift of 0.25 and an IMAG shift of 0.0?</p>
<p>You can double check with the <a class="reference internal" href="#tenth-ptr-solution"><span class="std std-ref">solution</span></a>.</p>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p>You will see</p>
<div class="highlight-bash"><div class="highlight"><pre><span></span>CheMPS2::DMRG::Symm4RDM<span class="o">(</span> X , Y <span class="o">)</span> : Elapsed wall <span class="nb">time</span> <span class="o">=</span> Z seconds.
</pre></div>
</div>
<p>appear in the output, with X and Y integers, and Z a floating point number. An estimate for the total wall time for the contraction of the 4-RDM with the Fock matrix is <span class="math">\(\frac{18 (18 + 1)}{2} Z\)</span> seconds.</p>
<p><strong>So this last exercise is homework!</strong></p>
<p>Compile <a class="reference external" href="https://github.com/sebwouters/chemps2">chemps2</a> on your institution’s HPC (or ask your admin or Sebastian to), and submit a non-interactive job for the DMRG-CASPT2 calculations.</p>
<p class="last">Yes, I have tricked you into using <a class="reference external" href="https://github.com/sebwouters/chemps2">chemps2</a> in the future!</p>
</div>
<div class="admonition note">
<p class="first admonition-title">Note</p>
<p>You can also find the precreated DMRG-CASPT2 checkpoints and the corresponding output in the folder <code class="docutils literal"><span class="pre">/apps/gent/tutorials/DMRG/</span></code>:</p>
<div class="last highlight-bash"><div class="highlight"><pre><span></span>$ cp /apps/gent/tutorials/DMRG/CheMPS2_f4rdm.h5.singlet pt2_singlet/.
$ cp /apps/gent/tutorials/DMRG/CheMPS2_MPS0.h5.singlet pt2_singlet/.
$ less /apps/gent/tutorials/DMRG/pt2_singlet.out.0.0
$ less /apps/gent/tutorials/DMRG/pt2_singlet.out.0.25
$ cp /apps/gent/tutorials/DMRG/CheMPS2_f4rdm.h5.triplet pt2_triplet/.
$ cp /apps/gent/tutorials/DMRG/CheMPS2_MPS0.h5.triplet pt2_triplet/.
$ less /apps/gent/tutorials/DMRG/pt2_triplet.out.0.0
$ less /apps/gent/tutorials/DMRG/pt2_triplet.out.0.25
</pre></div>
</div>
</div>
<p>To study an example DMRG-CASPT2 output during this workshop, perform a small active space calculation. For example:</p>
<div class="highlight-bash"><div class="highlight"><pre><span></span>$ mkdir small_caspt2/
$ <span class="nb">cd</span> small_caspt2/
$ wget <span class="s1">'https://github.com/sebwouters/chemps2/raw/master/tests/matrixelements/N2.CCPVDZ.FCIDUMP'</span>
$ wget <span class="s1">'https://github.com/sebwouters/chemps2/raw/master/tests/test14.input'</span>
$ sed -i <span class="s2">"s/\/path\/to/./"</span> test14.input
$ sed -i <span class="s2">"s/\/tmp/\/local\/NUMBER.master15.delcatty.gent.vsc\//"</span> test14.input
$ cat test14.input
$ chemps2 --file<span class="o">=</span>test14.input <span class="p">&</span>> test14.output <span class="p">&</span>
$ tail -n <span class="m">3000</span> -f test14.output
</pre></div>
</div>
<p>Do you know the difference between the diagonal, non-variational, and variational second order perturbation energies? How is the reference weight calculated and what does it mean?</p>
<div class="highlight-bash"><div class="highlight"><pre><span></span>$ grep <span class="s2">"E2"</span> test14.output
$ grep <span class="s2">"Reference weight"</span> test14.output
</pre></div>
</div>
</div>
<div class="section" id="solutions">
<h2>12.7. Solutions<a class="headerlink" href="#solutions" title="Permalink to this headline">¶</a></h2>
<div class="section" id="ci-input-orbs-in">
<span id="first-ptr-solution"></span><h3>12.7.1. ci_input_orbs.in<a class="headerlink" href="#ci-input-orbs-in" title="Permalink to this headline">¶</a></h3>
<div class="highlight-bash"><div class="highlight"><pre><span></span><span class="nv">FCIDUMP</span> <span class="o">=</span> /path/to/TETRACENE.FCIDUMP
<span class="nv">GROUP</span> <span class="o">=</span> <span class="m">3</span>
<span class="nv">MULTIPLICITY</span> <span class="o">=</span> <span class="m">1</span>
<span class="nv">NELECTRONS</span> <span class="o">=</span> <span class="m">120</span>
<span class="nv">IRREP</span> <span class="o">=</span> <span class="m">0</span>
<span class="nv">EXCITATION</span> <span class="o">=</span> <span class="m">0</span>
<span class="nv">SWEEP_STATES</span> <span class="o">=</span> <span class="m">200</span>, <span class="m">400</span>, <span class="m">600</span>, <span class="m">600</span>, <span class="m">400</span>, <span class="m">200</span>
<span class="nv">SWEEP_ENERGY_CONV</span> <span class="o">=</span> 1e-6, 1e-6, 1e-6, 1e-8, 1e-8, 1e-8
<span class="nv">SWEEP_MAX_SWEEPS</span> <span class="o">=</span> <span class="m">10</span>, <span class="m">10</span>, <span class="m">10</span>, <span class="m">3</span>, <span class="m">3</span>, <span class="m">3</span>
<span class="nv">SWEEP_NOISE_PREFAC</span> <span class="o">=</span> <span class="m">0</span>.05, <span class="m">0</span>.05, <span class="m">0</span>.05, <span class="m">0</span>.0, <span class="m">0</span>.0, <span class="m">0</span>.0
<span class="nv">SWEEP_DVDSON_RTOL</span> <span class="o">=</span> 1e-5, 1e-5, 1e-5, 1e-5, 1e-5, 1e-5
<span class="nv">NOCC</span> <span class="o">=</span> <span class="m">51</span>, <span class="m">0</span>
<span class="nv">NACT</span> <span class="o">=</span> <span class="m">0</span>, <span class="m">18</span>
<span class="nv">NVIR</span> <span class="o">=</span> <span class="m">171</span>, <span class="m">54</span>
<span class="nv">SCF_STATE_AVG</span> <span class="o">=</span> FALSE
<span class="nv">SCF_DIIS_THR</span> <span class="o">=</span> <span class="m">0</span>.0
<span class="nv">SCF_GRAD_THR</span> <span class="o">=</span> 1e-6
<span class="nv">SCF_MAX_ITER</span> <span class="o">=</span> <span class="m">1</span>
<span class="nv">SCF_ACTIVE_SPACE</span> <span class="o">=</span> I
<span class="nv">SCF_MOLDEN</span> <span class="o">=</span> /path/to/tetracene.molden
<span class="nv">CASPT2_CALC</span> <span class="o">=</span> FALSE
<span class="nv">CASPT2_ORBS</span> <span class="o">=</span> A
<span class="nv">CASPT2_IPEA</span> <span class="o">=</span> <span class="m">0</span>.0
<span class="nv">CASPT2_IMAG</span> <span class="o">=</span> <span class="m">0</span>.0
<span class="nv">CASPT2_CHECKPT</span> <span class="o">=</span> FALSE
<span class="nv">CASPT2_CUMUL</span> <span class="o">=</span> FALSE
<span class="nv">PRINT_CORR</span> <span class="o">=</span> TRUE
<span class="nv">TMP_FOLDER</span> <span class="o">=</span> /local/NUMBER.master15.delcatty.gent.vsc/
</pre></div>
</div>
</div>
<div class="section" id="ci-local-orbs-in">
<span id="second-ptr-solution"></span><h3>12.7.2. ci_local_orbs.in<a class="headerlink" href="#ci-local-orbs-in" title="Permalink to this headline">¶</a></h3>
<p>Difference with <a class="reference internal" href="#first-ptr-solution"><span class="std std-ref">input orbitals</span></a>:</p>
<div class="highlight-bash"><div class="highlight"><pre><span></span><span class="nv">SCF_ACTIVE_SPACE</span> <span class="o">=</span> L
</pre></div>
</div>
</div>
<div class="section" id="tetracene-molden-rotated-for-the-localized-active-space-orbitals">
<span id="third-ptr-solution"></span><h3>12.7.3. tetracene.molden.rotated for the localized active space orbitals<a class="headerlink" href="#tetracene-molden-rotated-for-the-localized-active-space-orbitals" title="Permalink to this headline">¶</a></h3>
<img alt="_images/handson_orbitals.png" src="_images/handson_orbitals.png" />
<p>For <code class="docutils literal"><span class="pre">ci_local_orbs/tetracene.molden.rotated</span></code>, the active space orbitals are localized on the carbon atoms, and are ordered according to the one-dimensional topology of the molecule.</p>
</div>
<div class="section" id="molecular-vs-localized-orbitals">
<span id="fourth-ptr-solution"></span><h3>12.7.4. Molecular vs. localized orbitals<a class="headerlink" href="#molecular-vs-localized-orbitals" title="Permalink to this headline">¶</a></h3>
<img alt="_images/handson_comparison.png" src="_images/handson_comparison.png" />
</div>
<div class="section" id="scf-singlet-in">
<span id="fifth-ptr-solution"></span><h3>12.7.5. scf_singlet.in<a class="headerlink" href="#scf-singlet-in" title="Permalink to this headline">¶</a></h3>
<div class="highlight-bash"><div class="highlight"><pre><span></span><span class="nv">FCIDUMP</span> <span class="o">=</span> /path/to/TETRACENE.FCIDUMP
<span class="nv">GROUP</span> <span class="o">=</span> <span class="m">3</span>
<span class="nv">MULTIPLICITY</span> <span class="o">=</span> <span class="m">1</span>
<span class="nv">NELECTRONS</span> <span class="o">=</span> <span class="m">120</span>
<span class="nv">IRREP</span> <span class="o">=</span> <span class="m">0</span>
<span class="nv">EXCITATION</span> <span class="o">=</span> <span class="m">0</span>
<span class="nv">SWEEP_STATES</span> <span class="o">=</span> <span class="m">250</span>, <span class="m">500</span>, <span class="m">750</span>
<span class="nv">SWEEP_ENERGY_CONV</span> <span class="o">=</span> 1e-6, 1e-8, 1e-10
<span class="nv">SWEEP_MAX_SWEEPS</span> <span class="o">=</span> <span class="m">8</span>, <span class="m">8</span>, <span class="m">8</span>
<span class="nv">SWEEP_NOISE_PREFAC</span> <span class="o">=</span> <span class="m">0</span>.05, <span class="m">0</span>.05, <span class="m">0</span>.0
<span class="nv">SWEEP_DVDSON_RTOL</span> <span class="o">=</span> 1e-5, 1e-5, 1e-8
<span class="nv">NOCC</span> <span class="o">=</span> <span class="m">51</span>, <span class="m">0</span>
<span class="nv">NACT</span> <span class="o">=</span> <span class="m">0</span>, <span class="m">18</span>
<span class="nv">NVIR</span> <span class="o">=</span> <span class="m">171</span>, <span class="m">54</span>
<span class="nv">SCF_STATE_AVG</span> <span class="o">=</span> FALSE
<span class="nv">SCF_DIIS_THR</span> <span class="o">=</span> 1e-2
<span class="nv">SCF_GRAD_THR</span> <span class="o">=</span> 1e-6
<span class="nv">SCF_MAX_ITER</span> <span class="o">=</span> <span class="m">100</span>
<span class="nv">SCF_ACTIVE_SPACE</span> <span class="o">=</span> L
<span class="nv">CASPT2_CALC</span> <span class="o">=</span> FALSE
<span class="nv">CASPT2_ORBS</span> <span class="o">=</span> A
<span class="nv">CASPT2_IPEA</span> <span class="o">=</span> <span class="m">0</span>.0
<span class="nv">CASPT2_IMAG</span> <span class="o">=</span> <span class="m">0</span>.0
<span class="nv">CASPT2_CHECKPT</span> <span class="o">=</span> FALSE
<span class="nv">CASPT2_CUMUL</span> <span class="o">=</span> FALSE
<span class="nv">PRINT_CORR</span> <span class="o">=</span> TRUE
<span class="nv">TMP_FOLDER</span> <span class="o">=</span> /local/NUMBER.master15.delcatty.gent.vsc/
</pre></div>
</div>
</div>
<div class="section" id="scf-triplet-in">
<span id="sixth-ptr-solution"></span><h3>12.7.6. scf_triplet.in<a class="headerlink" href="#scf-triplet-in" title="Permalink to this headline">¶</a></h3>
<p>Difference with <a class="reference internal" href="#fifth-ptr-solution"><span class="std std-ref">singlet</span></a>:</p>
<div class="highlight-bash"><div class="highlight"><pre><span></span><span class="nv">MULTIPLICITY</span> <span class="o">=</span> <span class="m">3</span>
</pre></div>
</div>
</div>
<div class="section" id="dmrg-scf-singlet-triplet-gap">
<span id="seventh-ptr-solution"></span><h3>12.7.7. DMRG-SCF singlet-triplet gap<a class="headerlink" href="#dmrg-scf-singlet-triplet-gap" title="Permalink to this headline">¶</a></h3>
<p>Both DMRG-SCF calculations are converged with 8 macro-iterations. The gap is</p>
<div class="math">
\[\Delta E = E_{triplet} - E_{singlet} = -688.803387 - (-688.867150) ~ E_{h} = 63.763 ~ mE_{h} = 40.012 ~ kcal/mol\]</div>
</div>
<div class="section" id="pt2-singlet-in">
<span id="eigth-ptr-solution"></span><h3>12.7.8. pt2_singlet.in<a class="headerlink" href="#pt2-singlet-in" title="Permalink to this headline">¶</a></h3>
<div class="highlight-bash"><div class="highlight"><pre><span></span><span class="nv">FCIDUMP</span> <span class="o">=</span> /path/to/TETRACENE.FCIDUMP
<span class="nv">GROUP</span> <span class="o">=</span> <span class="m">3</span>
<span class="nv">MULTIPLICITY</span> <span class="o">=</span> <span class="m">1</span>
<span class="nv">NELECTRONS</span> <span class="o">=</span> <span class="m">120</span>
<span class="nv">IRREP</span> <span class="o">=</span> <span class="m">0</span>
<span class="nv">EXCITATION</span> <span class="o">=</span> <span class="m">0</span>
<span class="nv">SWEEP_STATES</span> <span class="o">=</span> <span class="m">250</span>, <span class="m">500</span>, <span class="m">750</span>
<span class="nv">SWEEP_ENERGY_CONV</span> <span class="o">=</span> 1e-6, 1e-8, 1e-10
<span class="nv">SWEEP_MAX_SWEEPS</span> <span class="o">=</span> <span class="m">8</span>, <span class="m">8</span>, <span class="m">8</span>
<span class="nv">SWEEP_NOISE_PREFAC</span> <span class="o">=</span> <span class="m">0</span>.05, <span class="m">0</span>.05, <span class="m">0</span>.0
<span class="nv">SWEEP_DVDSON_RTOL</span> <span class="o">=</span> 1e-5, 1e-5, 1e-8
<span class="nv">NOCC</span> <span class="o">=</span> <span class="m">51</span>, <span class="m">0</span>
<span class="nv">NACT</span> <span class="o">=</span> <span class="m">0</span>, <span class="m">18</span>
<span class="nv">NVIR</span> <span class="o">=</span> <span class="m">171</span>, <span class="m">54</span>
<span class="nv">SCF_STATE_AVG</span> <span class="o">=</span> FALSE
<span class="nv">SCF_DIIS_THR</span> <span class="o">=</span> <span class="m">0</span>.0
<span class="nv">SCF_GRAD_THR</span> <span class="o">=</span> 1e-6
<span class="nv">SCF_MAX_ITER</span> <span class="o">=</span> <span class="m">100</span>
<span class="nv">SCF_ACTIVE_SPACE</span> <span class="o">=</span> I
<span class="nv">CASPT2_CALC</span> <span class="o">=</span> TRUE
<span class="nv">CASPT2_ORBS</span> <span class="o">=</span> A
<span class="nv">CASPT2_IPEA</span> <span class="o">=</span> <span class="m">0</span>.0
<span class="nv">CASPT2_IMAG</span> <span class="o">=</span> <span class="m">0</span>.0
<span class="nv">CASPT2_CHECKPT</span> <span class="o">=</span> TRUE
<span class="nv">CASPT2_CUMUL</span> <span class="o">=</span> FALSE
<span class="nv">PRINT_CORR</span> <span class="o">=</span> TRUE
<span class="nv">TMP_FOLDER</span> <span class="o">=</span> /local/NUMBER.master15.delcatty.gent.vsc/
</pre></div>
</div>
</div>
<div class="section" id="pt2-triplet-in">
<span id="nineth-ptr-solution"></span><h3>12.7.9. pt2_triplet.in<a class="headerlink" href="#pt2-triplet-in" title="Permalink to this headline">¶</a></h3>
<p>Difference with <a class="reference internal" href="#eigth-ptr-solution"><span class="std std-ref">singlet</span></a>:</p>
<div class="highlight-bash"><div class="highlight"><pre><span></span><span class="nv">MULTIPLICITY</span> <span class="o">=</span> <span class="m">3</span>
</pre></div>
</div>
</div>
<div class="section" id="dmrg-caspt2-singlet-triplet-gaps">
<span id="tenth-ptr-solution"></span><h3>12.7.10. DMRG-CASPT2 singlet-triplet gaps<a class="headerlink" href="#dmrg-caspt2-singlet-triplet-gaps" title="Permalink to this headline">¶</a></h3>
<p>For IPEA = 0.0 a.u. the gap is</p>
<div class="math">
\[\Delta E = E_{triplet} - E_{singlet} = -690.945663 - (-691.000608) ~ E_{h} = 54.945 ~ mE_{h} = 34.479 ~ kcal/mol\]</div>
<p>and for IPEA = 0.25 a.u. the gap is</p>
<div class="math">
\[\Delta E = E_{triplet} - E_{singlet} = -690.923604 - (-690.987560) ~ E_{h} = 63.956 ~ mE_{h} = 40.133 ~ kcal/mol\]</div>
</div>
</div>
</div>
</div>
</div>
</div>
<div class="sphinxsidebar" role="navigation" aria-label="main navigation">
<div class="sphinxsidebarwrapper">
<p class="logo"><a href="index.html">
<img class="logo" src="_static/CheMPS2logo.png" alt="Logo"/>
</a></p>
<h3><a href="index.html">Table Of Contents</a></h3>
<ul>
<li><a class="reference internal" href="#">12. DMRG workshop (12-jul-2016): hands-on session</a><ul>
<li><a class="reference internal" href="#introduction">12.1. Introduction</a></li>
<li><a class="reference internal" href="#ugent-hpc">12.2. UGent HPC</a></li>
<li><a class="reference internal" href="#fcidump-and-molden">12.3. <code class="docutils literal"><span class="pre">FCIDUMP</span></code> and <code class="docutils literal"><span class="pre">MOLDEN</span></code></a></li>
<li><a class="reference internal" href="#basis-choice">12.4. Basis choice</a></li>
<li><a class="reference internal" href="#dmrg-scf">12.5. DMRG-SCF</a></li>
<li><a class="reference internal" href="#dmrg-caspt2">12.6. DMRG-CASPT2</a></li>
<li><a class="reference internal" href="#solutions">12.7. Solutions</a><ul>
<li><a class="reference internal" href="#ci-input-orbs-in">12.7.1. ci_input_orbs.in</a></li>
<li><a class="reference internal" href="#ci-local-orbs-in">12.7.2. ci_local_orbs.in</a></li>
<li><a class="reference internal" href="#tetracene-molden-rotated-for-the-localized-active-space-orbitals">12.7.3. tetracene.molden.rotated for the localized active space orbitals</a></li>
<li><a class="reference internal" href="#molecular-vs-localized-orbitals">12.7.4. Molecular vs. localized orbitals</a></li>
<li><a class="reference internal" href="#scf-singlet-in">12.7.5. scf_singlet.in</a></li>
<li><a class="reference internal" href="#scf-triplet-in">12.7.6. scf_triplet.in</a></li>
<li><a class="reference internal" href="#dmrg-scf-singlet-triplet-gap">12.7.7. DMRG-SCF singlet-triplet gap</a></li>
<li><a class="reference internal" href="#pt2-singlet-in">12.7.8. pt2_singlet.in</a></li>
<li><a class="reference internal" href="#pt2-triplet-in">12.7.9. pt2_triplet.in</a></li>
<li><a class="reference internal" href="#dmrg-caspt2-singlet-triplet-gaps">12.7.10. DMRG-CASPT2 singlet-triplet gaps</a></li>
</ul>
</li>
</ul>
</li>
</ul>
<h4>Previous topic</h4>
<p class="topless"><a href="interfaces.html"
title="previous chapter">11. Interfaces to psi4 and pyscf</a></p>
<div role="note" aria-label="source link">
<h3>This Page</h3>
<ul class="this-page-menu">
<li><a href="_sources/handson.rst.txt"
rel="nofollow">Show Source</a></li>
</ul>
</div>
<div id="searchbox" style="display: none" role="search">
<h3>Quick search</h3>
<form class="search" action="search.html" method="get">
<div><input type="text" name="q" /></div>
<div><input type="submit" value="Go" /></div>
<input type="hidden" name="check_keywords" value="yes" />
<input type="hidden" name="area" value="default" />
</form>
</div>
<script type="text/javascript">$('#searchbox').show(0);</script>
</div>
</div>
<div class="clearer"></div>
</div>
<div class="related" role="navigation" aria-label="related navigation">
<h3>Navigation</h3>
<ul>
<li class="right" style="margin-right: 10px">
<a href="genindex.html" title="General Index"
>index</a></li>
<li class="right" >
<a href="interfaces.html" title="11. Interfaces to psi4 and pyscf"
>previous</a> |</li>
<li class="nav-item nav-item-0"><a href="index.html">CheMPS2 1.8.5 (2018-01-14) documentation</a> »</li>
</ul>
</div>
<div class="footer" role="contentinfo">
© Copyright 2013-2018, Sebastian Wouters.
Created using <a href="http://sphinx-doc.org/">Sphinx</a> 1.6.6.
</div>
</body>
</html>
|