This file is indexed.

/usr/share/doc/bagel/html/grad/force.html is in bagel 1.1.0-1.

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
<!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>Nuclear gradient and derivative coupling &#8212; BAGEL Manual</title>
    <link rel="stylesheet" href="../_static/override.css" type="text/css" />
    <link rel="stylesheet" href="../_static/pygments.css" type="text/css" />
    <script type="text/javascript">
      var DOCUMENTATION_OPTIONS = {
        URL_ROOT:    '../',
        VERSION:     '1.0.0',
        COLLAPSE_INDEX: false,
        FILE_SUFFIX: '.html',
        HAS_SOURCE:  true,
        SOURCELINK_SUFFIX: '.txt'
      };
    </script>
    <script type="text/javascript" src="../_static/jquery.js"></script>
    <script type="text/javascript" src="../_static/underscore.js"></script>
    <script type="text/javascript" src="../_static/doctools.js"></script>
    <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script>
    <link rel="search" title="Search" href="../search.html" />
    <link rel="next" title="Molecular geometry optimization" href="../opt/optimize.html" />
    <link rel="prev" title="Description of input structure" href="methods.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="../opt/optimize.html" title="Molecular geometry optimization"
             accesskey="N">next</a></li>
        <li class="right" >
          <a href="methods.html" title="Description of input structure"
             accesskey="P">previous</a> |</li>
        <li class="nav-item nav-item-0"><a href="../index.html">BAGEL Manual</a> &#187;</li>
          <li class="nav-item nav-item-1"><a href="../user-manual.html" ><strong>BAGEL user manual</strong></a> &#187;</li>
          <li class="nav-item nav-item-2"><a href="grad.html" accesskey="U">Nuclear gradients and related functionalities</a> &#187;</li> 
      </ul>
    </div>  

    <div class="document">
      <div class="documentwrapper">
        <div class="bodywrapper">
          <div class="body" role="main">
            
  <div class="section" id="nuclear-gradient-and-derivative-coupling">
<span id="force"></span><h1>Nuclear gradient and derivative coupling<a class="headerlink" href="#nuclear-gradient-and-derivative-coupling" title="Permalink to this headline"></a></h1>
<div class="section" id="description">
<h2>Description<a class="headerlink" href="#description" title="Permalink to this headline"></a></h2>
<p>The force section can be used to compute the analytical gradient (force), the numerical gradient by finite difference, or the non-adiabatic coupling matrix elements (NACME). Analytical gradients are implemented for unrestricted Hartree–Fock (UHF), restricted open-shell Hartree–Fock (ROHF), restricted Hartree–Fock (RHF), Dirac–Hartree–Fock (DHF), Møller–Plesset perturbation theory (MP2), complete active space self consistent field (CASSCF), and multireference perturbation theory (CASPT2). For CASSCF and CASPT2, it is also possible to perform multiple evaluations of the gradients without repeating the energy calculations.
In addition, the relaxed density in MP2, SA-CASSCF, and CASPT2 calculations can be printed in the Gaussian Cube format.</p>
</div>
<div class="section" id="keywords">
<h2>Keywords<a class="headerlink" href="#keywords" title="Permalink to this headline"></a></h2>
<div class="section" id="required-keywords">
<h3>Required Keywords<a class="headerlink" href="#required-keywords" title="Permalink to this headline"></a></h3>
<div class="topic">
<p class="topic-title first"><code class="docutils literal"><span class="pre">title</span></code></p>
<div class="line-block">
<div class="line"><strong>Description:</strong> The title of the type of gradient calculation being performed.</div>
<div class="line"><strong>Datatype:</strong> string</div>
<div class="line"><strong>Values:</strong> (force, nacme, dgrad, forces)</div>
<div class="line-block">
<div class="line"><code class="docutils literal"><span class="pre">force</span></code>: Calculates the gradient (force)</div>
<div class="line"><code class="docutils literal"><span class="pre">nacme</span></code>: Calculates the non-adiabatic coupling matrix elements</div>
<div class="line"><code class="docutils literal"><span class="pre">dgrad</span></code>: Difference gradient (only available for CASSCF)</div>
<div class="line"><code class="docutils literal"><span class="pre">forces</span></code>: Calculates many gradients [available for multi-state methods, such as SA-CASSCF and (X)MS-CASPT2]</div>
</div>
<div class="line"><strong>Default:</strong> N/A</div>
</div>
</div>
<div class="topic">
<p class="topic-title first"><code class="docutils literal"><span class="pre">method</span></code></p>
<div class="line-block">
<div class="line"><strong>Description:</strong> The method input block allows the user to specify one or more methods to be used in the gradient calculation. See section on input structure for more information.</div>
</div>
</div>
<div class="topic">
<p class="topic-title first"><code class="docutils literal"><span class="pre">grads</span></code></p>
<div class="line-block">
<div class="line"><strong>Description:</strong> The grads input block allows the user to specify one or more gradients to be calculated. The keywords <code class="docutils literal"><span class="pre">title</span></code>, <code class="docutils literal"><span class="pre">target</span></code>, <code class="docutils literal"><span class="pre">target2</span></code>, <code class="docutils literal"><span class="pre">nacmtype</span></code>, <code class="docutils literal"><span class="pre">maxziter</span></code> can be specified for each gradient evaluation. See below for example.</div>
</div>
</div>
<div class="topic">
<p class="topic-title first"><code class="docutils literal"><span class="pre">nacmtype</span></code></p>
<div class="line-block">
<div class="line"><strong>Description:</strong> Type of non-adiabatic coupling matrix element to be computed</div>
<div class="line"><strong>Datatype:</strong> string</div>
<div class="line"><strong>Values:</strong></div>
<div class="line-block">
<div class="line"><code class="docutils literal"><span class="pre">full</span></code>: Full non-adiabatic coupling</div>
<div class="line"><code class="docutils literal"><span class="pre">interstate</span></code>: Interstate coupling</div>
<div class="line"><code class="docutils literal"><span class="pre">etf</span></code>: Non-adiabtic coupling with built-in electronic translational factor (ETF)</div>
<div class="line"><code class="docutils literal"><span class="pre">noweight</span></code>: Interstate coupling without weighting it by energy gap</div>
</div>
<div class="line"><strong>Default:</strong> full.</div>
</div>
</div>
</div>
<div class="section" id="optional-keywords">
<h3>Optional Keywords<a class="headerlink" href="#optional-keywords" title="Permalink to this headline"></a></h3>
<div class="topic">
<p class="topic-title first"><code class="docutils literal"><span class="pre">numerical</span></code></p>
<div class="line-block">
<div class="line"><strong>Description:</strong> The gradients will be computed by finite difference.</div>
<div class="line"><strong>Datatype:</strong> bool</div>
<div class="line"><strong>Values:</strong></div>
<div class="line-block">
<div class="line"><code class="docutils literal"><span class="pre">true</span></code>: Uses finite difference</div>
<div class="line"><code class="docutils literal"><span class="pre">false</span></code> : Uses analytical gradient</div>
</div>
<div class="line"><strong>Default:</strong> false</div>
<div class="line"><strong>Recommendation:</strong> If available, use analytical gradient. If analytical gradient is not available, BAGEL automatically switches to numerical gradient.</div>
</div>
</div>
<div class="topic">
<p class="topic-title first"><code class="docutils literal"><span class="pre">dx</span></code></p>
<div class="line-block">
<div class="line"><strong>Description:</strong> The step size used in the displacements in the finite difference calculations. The units are bohr.</div>
<div class="line"><strong>Datatype:</strong> double precision</div>
<div class="line"><strong>Default:</strong> 1.0e-3</div>
</div>
</div>
<div class="topic">
<p class="topic-title first"><code class="docutils literal"><span class="pre">target</span></code></p>
<div class="line-block">
<div class="line"><strong>Description:</strong> The target state for the energy and gradient evaluation (e.g. which state in a state-averaged CASSCF calculation)</div>
<div class="line"><strong>Datatype:</strong> int</div>
<div class="line"><strong>Values:</strong></div>
<div class="line-block">
<div class="line"><code class="docutils literal"><span class="pre">int</span></code>: ground state = 0</div>
</div>
<div class="line"><strong>Default:</strong> 0</div>
</div>
</div>
<div class="topic">
<p class="topic-title first"><code class="docutils literal"><span class="pre">target2</span></code></p>
<div class="line-block">
<div class="line"><strong>Description:</strong> In an NACME or DGRAD calculation, target2 designates the target state for the second state.</div>
<div class="line"><strong>Datatype:</strong> int</div>
<div class="line"><strong>Values:</strong></div>
<div class="line-block">
<div class="line"><code class="docutils literal"><span class="pre">int</span></code>: first exited state = 1</div>
</div>
<div class="line"><strong>Default:</strong> 1</div>
</div>
</div>
<div class="topic">
<p class="topic-title first"><code class="docutils literal"><span class="pre">dipole</span></code></p>
<div class="line-block">
<div class="line"><strong>Description:</strong> Calculate unrelaxed (transition) dipole moments, available in SA-CASSCF and XMS-CASPT2.</div>
<div class="line"><strong>Datatype:</strong> bool</div>
<div class="line"><strong>Default:</strong> false</div>
</div>
</div>
<div class="topic">
<p class="topic-title first"><code class="docutils literal"><span class="pre">export</span></code></p>
<div class="line-block">
<div class="line"><strong>Description:</strong> This option will export the nuclear gradient to a text file.</div>
<div class="line"><strong>Datatype:</strong> bool</div>
<div class="line"><strong>Default:</strong> false</div>
<div class="line"><strong>Recommendation:</strong> This is used to interface with the QM/MM program. See section on non-adiabatic dynamics.</div>
</div>
</div>
<div class="topic">
<p class="topic-title first"><code class="docutils literal"><span class="pre">export_single</span></code></p>
<div class="line-block">
<div class="line"><strong>Description:</strong> This option will export the nuclear gradient to a text file for a single state.</div>
<div class="line"><strong>Datatype:</strong> bool</div>
<div class="line"><strong>Default:</strong> false</div>
<div class="line"><strong>Recommendation:</strong> This is used to interface with the QM/MM program. See section on non-adiabatic dynamics.</div>
</div>
</div>
<div class="topic">
<p class="topic-title first"><code class="docutils literal"><span class="pre">maxziter</span></code></p>
<div class="line-block">
<div class="line"><strong>Description:</strong> Maximum number of Z-vector iterations for gradient evaluation. Applies to SA-CASSCF, CASPT2, and MP2 calculations.</div>
<div class="line"><strong>Datatype:</strong> int</div>
<div class="line"><strong>Default:</strong> 100</div>
<div class="line"><strong>Recommendation:</strong> Increase the value when Z-vector equation does not converge.</div>
</div>
</div>
<div class="topic">
<p class="topic-title first"><code class="docutils literal"><span class="pre">nproc</span></code></p>
<div class="line-block">
<div class="line"><strong>Description:</strong> The numerical gradient code is embarrassingly parallelized so that the displacements in the finite difference calculations can be run at the same time. The nproc keyword allows the user to specify the number of MPI processes to be used for each energy calculation.</div>
<div class="line"><strong>Datatype:</strong> int</div>
<div class="line"><strong>Default:</strong> 1</div>
</div>
</div>
<div class="topic">
<p class="topic-title first"><code class="docutils literal"><span class="pre">density_print</span></code></p>
<div class="line-block">
<div class="line"><strong>Description:</strong> Print relaxed densities in the Gaussian Cube format. Applies to SA-CASSCF, CASPT2, and MP2 calculations. The options for density printing can be specified in <code class="docutils literal"><span class="pre">moprint</span></code> block (see below for example and <a class="reference internal" href="../miscellaneous/moprint.html#moprint"><span class="std std-ref">here</span></a> for the keywords).</div>
<div class="line"><strong>Datatype:</strong> bool</div>
<div class="line"><strong>Default:</strong> false</div>
</div>
</div>
</div>
</div>
<div class="section" id="example">
<h2>Example<a class="headerlink" href="#example" title="Permalink to this headline"></a></h2>
<p>The benzophenone molecule</p>
<div class="align-center figure" id="id1">
<a class="reference internal image-reference" href="../_images/benzophenone.png"><img alt="alternate text" src="../_images/benzophenone.png" style="width: 200px;" /></a>
<p class="caption"><span class="caption-text">The benzophenone molecule with carbon atoms in grey, oxygen in red, and hydrogen in white.</span></p>
</div>
<div class="section" id="sample-input-force">
<h3>Sample input: force<a class="headerlink" href="#sample-input-force" title="Permalink to this headline"></a></h3>
<div class="highlight-javascript"><div class="highlight"><pre><span></span> <span class="p">{</span> <span class="s2">&quot;bagel&quot;</span> <span class="o">:</span> <span class="p">[</span>

 <span class="p">{</span>
   <span class="s2">&quot;title&quot;</span> <span class="o">:</span> <span class="s2">&quot;molecule&quot;</span><span class="p">,</span>
   <span class="s2">&quot;basis&quot;</span> <span class="o">:</span> <span class="s2">&quot;cc-pvdz&quot;</span><span class="p">,</span>
   <span class="s2">&quot;df_basis&quot;</span> <span class="o">:</span> <span class="s2">&quot;cc-pvdz-jkfit&quot;</span><span class="p">,</span>
   <span class="s2">&quot;angstrom&quot;</span> <span class="o">:</span> <span class="kc">false</span><span class="p">,</span>
   <span class="s2">&quot;geometry&quot;</span> <span class="o">:</span> <span class="p">[</span>
   <span class="p">{</span> <span class="s2">&quot;atom&quot;</span> <span class="o">:</span> <span class="s2">&quot;C&quot;</span><span class="p">,</span> <span class="s2">&quot;xyz&quot;</span> <span class="o">:</span> <span class="p">[</span>     <span class="o">-</span><span class="mf">2.002493</span><span class="p">,</span>     <span class="o">-</span><span class="mf">2.027773</span><span class="p">,</span>      <span class="mf">0.004882</span> <span class="p">]</span> <span class="p">},</span>
   <span class="p">{</span> <span class="s2">&quot;atom&quot;</span> <span class="o">:</span> <span class="s2">&quot;C&quot;</span><span class="p">,</span> <span class="s2">&quot;xyz&quot;</span> <span class="o">:</span> <span class="p">[</span>     <span class="o">-</span><span class="mf">2.506057</span><span class="p">,</span>     <span class="o">-</span><span class="mf">4.613700</span><span class="p">,</span>      <span class="mf">0.009896</span> <span class="p">]</span> <span class="p">},</span>
   <span class="p">{</span> <span class="s2">&quot;atom&quot;</span> <span class="o">:</span> <span class="s2">&quot;C&quot;</span><span class="p">,</span> <span class="s2">&quot;xyz&quot;</span> <span class="o">:</span> <span class="p">[</span>      <span class="mf">0.536515</span><span class="p">,</span>     <span class="o">-</span><span class="mf">1.276360</span><span class="p">,</span>      <span class="mf">0.003515</span> <span class="p">]</span> <span class="p">},</span>
   <span class="p">{</span> <span class="s2">&quot;atom&quot;</span> <span class="o">:</span> <span class="s2">&quot;C&quot;</span><span class="p">,</span> <span class="s2">&quot;xyz&quot;</span> <span class="o">:</span> <span class="p">[</span>     <span class="o">-</span><span class="mf">0.558724</span><span class="p">,</span>     <span class="o">-</span><span class="mf">6.375134</span><span class="p">,</span>      <span class="mf">0.013503</span> <span class="p">]</span> <span class="p">},</span>
   <span class="p">{</span> <span class="s2">&quot;atom&quot;</span> <span class="o">:</span> <span class="s2">&quot;H&quot;</span><span class="p">,</span> <span class="s2">&quot;xyz&quot;</span> <span class="o">:</span> <span class="p">[</span>     <span class="o">-</span><span class="mf">4.396140</span><span class="p">,</span>     <span class="o">-</span><span class="mf">5.341490</span><span class="p">,</span>      <span class="mf">0.011057</span> <span class="p">]</span> <span class="p">},</span>
   <span class="p">{</span> <span class="s2">&quot;atom&quot;</span> <span class="o">:</span> <span class="s2">&quot;C&quot;</span><span class="p">,</span> <span class="s2">&quot;xyz&quot;</span> <span class="o">:</span> <span class="p">[</span>      <span class="mf">2.478233</span><span class="p">,</span>     <span class="o">-</span><span class="mf">3.024614</span><span class="p">,</span>      <span class="mf">0.007049</span> <span class="p">]</span> <span class="p">},</span>
   <span class="p">{</span> <span class="s2">&quot;atom&quot;</span> <span class="o">:</span> <span class="s2">&quot;H&quot;</span><span class="p">,</span> <span class="s2">&quot;xyz&quot;</span> <span class="o">:</span> <span class="p">[</span>      <span class="mf">0.959539</span><span class="p">,</span>      <span class="mf">0.714937</span><span class="p">,</span>     <span class="o">-</span><span class="mf">0.000292</span> <span class="p">]</span> <span class="p">},</span>
   <span class="p">{</span> <span class="s2">&quot;atom&quot;</span> <span class="o">:</span> <span class="s2">&quot;C&quot;</span><span class="p">,</span> <span class="s2">&quot;xyz&quot;</span> <span class="o">:</span> <span class="p">[</span>      <span class="mf">1.936441</span><span class="p">,</span>     <span class="o">-</span><span class="mf">5.592475</span><span class="p">,</span>      <span class="mf">0.012127</span> <span class="p">]</span> <span class="p">},</span>
   <span class="p">{</span> <span class="s2">&quot;atom&quot;</span> <span class="o">:</span> <span class="s2">&quot;H&quot;</span><span class="p">,</span> <span class="s2">&quot;xyz&quot;</span> <span class="o">:</span> <span class="p">[</span>     <span class="o">-</span><span class="mf">1.012481</span><span class="p">,</span>     <span class="o">-</span><span class="mf">8.367883</span><span class="p">,</span>      <span class="mf">0.017419</span> <span class="p">]</span> <span class="p">},</span>
   <span class="p">{</span> <span class="s2">&quot;atom&quot;</span> <span class="o">:</span> <span class="s2">&quot;H&quot;</span><span class="p">,</span> <span class="s2">&quot;xyz&quot;</span> <span class="o">:</span> <span class="p">[</span>      <span class="mf">4.418042</span><span class="p">,</span>     <span class="o">-</span><span class="mf">2.380738</span><span class="p">,</span>      <span class="mf">0.005919</span> <span class="p">]</span> <span class="p">},</span>
   <span class="p">{</span> <span class="s2">&quot;atom&quot;</span> <span class="o">:</span> <span class="s2">&quot;H&quot;</span><span class="p">,</span> <span class="s2">&quot;xyz&quot;</span> <span class="o">:</span> <span class="p">[</span>      <span class="mf">3.448750</span><span class="p">,</span>     <span class="o">-</span><span class="mf">6.968581</span><span class="p">,</span>      <span class="mf">0.014980</span> <span class="p">]</span> <span class="p">},</span>
   <span class="p">{</span> <span class="s2">&quot;atom&quot;</span> <span class="o">:</span> <span class="s2">&quot;C&quot;</span><span class="p">,</span> <span class="s2">&quot;xyz&quot;</span> <span class="o">:</span> <span class="p">[</span>     <span class="o">-</span><span class="mf">6.758666</span><span class="p">,</span>     <span class="o">-</span><span class="mf">0.057378</span><span class="p">,</span>      <span class="mf">0.001157</span> <span class="p">]</span> <span class="p">},</span>
   <span class="p">{</span> <span class="s2">&quot;atom&quot;</span> <span class="o">:</span> <span class="s2">&quot;C&quot;</span><span class="p">,</span> <span class="s2">&quot;xyz&quot;</span> <span class="o">:</span> <span class="p">[</span>     <span class="o">-</span><span class="mf">8.231109</span><span class="p">,</span>     <span class="o">-</span><span class="mf">2.241648</span><span class="p">,</span>      <span class="mf">0.000224</span> <span class="p">]</span> <span class="p">},</span>
   <span class="p">{</span> <span class="s2">&quot;atom&quot;</span> <span class="o">:</span> <span class="s2">&quot;C&quot;</span><span class="p">,</span> <span class="s2">&quot;xyz&quot;</span> <span class="o">:</span> <span class="p">[</span>     <span class="o">-</span><span class="mf">8.022986</span><span class="p">,</span>      <span class="mf">2.269249</span><span class="p">,</span>      <span class="mf">0.001194</span> <span class="p">]</span> <span class="p">},</span>
   <span class="p">{</span> <span class="s2">&quot;atom&quot;</span> <span class="o">:</span> <span class="s2">&quot;C&quot;</span><span class="p">,</span> <span class="s2">&quot;xyz&quot;</span> <span class="o">:</span> <span class="p">[</span>    <span class="o">-</span><span class="mf">10.853532</span><span class="p">,</span>     <span class="o">-</span><span class="mf">2.110536</span><span class="p">,</span>     <span class="o">-</span><span class="mf">0.000769</span> <span class="p">]</span> <span class="p">},</span>
   <span class="p">{</span> <span class="s2">&quot;atom&quot;</span> <span class="o">:</span> <span class="s2">&quot;H&quot;</span><span class="p">,</span> <span class="s2">&quot;xyz&quot;</span> <span class="o">:</span> <span class="p">[</span>     <span class="o">-</span><span class="mf">7.410047</span><span class="p">,</span>     <span class="o">-</span><span class="mf">4.093049</span><span class="p">,</span>      <span class="mf">0.000224</span> <span class="p">]</span> <span class="p">},</span>
   <span class="p">{</span> <span class="s2">&quot;atom&quot;</span> <span class="o">:</span> <span class="s2">&quot;C&quot;</span><span class="p">,</span> <span class="s2">&quot;xyz&quot;</span> <span class="o">:</span> <span class="p">[</span>    <span class="o">-</span><span class="mf">10.632155</span><span class="p">,</span>      <span class="mf">2.405932</span><span class="p">,</span>      <span class="mf">0.000369</span> <span class="p">]</span> <span class="p">},</span>
   <span class="p">{</span> <span class="s2">&quot;atom&quot;</span> <span class="o">:</span> <span class="s2">&quot;H&quot;</span><span class="p">,</span> <span class="s2">&quot;xyz&quot;</span> <span class="o">:</span> <span class="p">[</span>     <span class="o">-</span><span class="mf">6.913797</span><span class="p">,</span>      <span class="mf">3.976253</span><span class="p">,</span>      <span class="mf">0.001805</span> <span class="p">]</span> <span class="p">},</span>
   <span class="p">{</span> <span class="s2">&quot;atom&quot;</span> <span class="o">:</span> <span class="s2">&quot;C&quot;</span><span class="p">,</span> <span class="s2">&quot;xyz&quot;</span> <span class="o">:</span> <span class="p">[</span>    <span class="o">-</span><span class="mf">12.064741</span><span class="p">,</span>      <span class="mf">0.207004</span><span class="p">,</span>     <span class="o">-</span><span class="mf">0.000695</span> <span class="p">]</span> <span class="p">},</span>
   <span class="p">{</span> <span class="s2">&quot;atom&quot;</span> <span class="o">:</span> <span class="s2">&quot;H&quot;</span><span class="p">,</span> <span class="s2">&quot;xyz&quot;</span> <span class="o">:</span> <span class="p">[</span>    <span class="o">-</span><span class="mf">11.941318</span><span class="p">,</span>     <span class="o">-</span><span class="mf">3.840822</span><span class="p">,</span>     <span class="o">-</span><span class="mf">0.001614</span> <span class="p">]</span> <span class="p">},</span>
   <span class="p">{</span> <span class="s2">&quot;atom&quot;</span> <span class="o">:</span> <span class="s2">&quot;H&quot;</span><span class="p">,</span> <span class="s2">&quot;xyz&quot;</span> <span class="o">:</span> <span class="p">[</span>    <span class="o">-</span><span class="mf">11.548963</span><span class="p">,</span>      <span class="mf">4.232744</span><span class="p">,</span>      <span class="mf">0.000447</span> <span class="p">]</span> <span class="p">},</span>
   <span class="p">{</span> <span class="s2">&quot;atom&quot;</span> <span class="o">:</span> <span class="s2">&quot;H&quot;</span><span class="p">,</span> <span class="s2">&quot;xyz&quot;</span> <span class="o">:</span> <span class="p">[</span>    <span class="o">-</span><span class="mf">14.107194</span><span class="p">,</span>      <span class="mf">0.302907</span><span class="p">,</span>     <span class="o">-</span><span class="mf">0.001460</span> <span class="p">]</span> <span class="p">},</span>
   <span class="p">{</span> <span class="s2">&quot;atom&quot;</span> <span class="o">:</span> <span class="s2">&quot;C&quot;</span><span class="p">,</span> <span class="s2">&quot;xyz&quot;</span> <span class="o">:</span> <span class="p">[</span>     <span class="o">-</span><span class="mf">3.892311</span><span class="p">,</span>      <span class="mf">0.136360</span><span class="p">,</span>      <span class="mf">0.001267</span> <span class="p">]</span> <span class="p">},</span>
   <span class="p">{</span> <span class="s2">&quot;atom&quot;</span> <span class="o">:</span> <span class="s2">&quot;O&quot;</span><span class="p">,</span> <span class="s2">&quot;xyz&quot;</span> <span class="o">:</span> <span class="p">[</span>     <span class="o">-</span><span class="mf">3.026383</span><span class="p">,</span>      <span class="mf">2.227189</span><span class="p">,</span>     <span class="o">-</span><span class="mf">0.001563</span> <span class="p">]</span> <span class="p">}</span>
   <span class="p">]</span>
 <span class="p">},</span>

 <span class="p">{</span>
   <span class="s2">&quot;title&quot;</span> <span class="o">:</span> <span class="s2">&quot;force&quot;</span><span class="p">,</span>
    <span class="s2">&quot;method&quot;</span> <span class="o">:</span> <span class="p">[</span> <span class="p">{</span>
     <span class="s2">&quot;title&quot;</span> <span class="o">:</span> <span class="s2">&quot;hf&quot;</span><span class="p">,</span>
     <span class="s2">&quot;thresh&quot;</span> <span class="o">:</span> <span class="mf">1.0e-12</span>
   <span class="p">}</span> <span class="p">]</span>
 <span class="p">}</span>
<span class="p">]}</span>
</pre></div>
</div>
<p>Using the same molecule block, a XMS-CASPT2 analytical gradient calculation can be performed.
In this particular example as is often the case, the active keyword is used to select the orbitals for the active space that includes 4 electrons and 3 orbitals.
Three sets of  <span class="math">\(\pi\)</span> and <span class="math">\(\pi^*\)</span> orbitals localized on the phenyl rings are included along with one non-bonding orbital (oxygen lone pair).
The CASSCF orbitals are state-averaged over two states.</p>
<div class="highlight-javascript"><div class="highlight"><pre><span></span><span class="p">{</span>
  <span class="s2">&quot;title&quot;</span> <span class="o">:</span> <span class="s2">&quot;casscf&quot;</span><span class="p">,</span>
  <span class="s2">&quot;nstate&quot;</span> <span class="o">:</span> <span class="mi">2</span><span class="p">,</span>
  <span class="s2">&quot;nclosed&quot;</span> <span class="o">:</span> <span class="mi">46</span><span class="p">,</span>
  <span class="s2">&quot;nact&quot;</span> <span class="o">:</span> <span class="mi">3</span><span class="p">,</span>
  <span class="s2">&quot;active&quot;</span> <span class="o">:</span> <span class="p">[</span><span class="mi">37</span><span class="p">,</span> <span class="mi">44</span><span class="p">,</span> <span class="mi">49</span><span class="p">]</span>
<span class="p">},</span>

<span class="p">{</span>
  <span class="s2">&quot;title&quot;</span> <span class="o">:</span> <span class="s2">&quot;force&quot;</span><span class="p">,</span>
   <span class="s2">&quot;target&quot;</span> <span class="o">:</span> <span class="mi">0</span><span class="p">,</span>
   <span class="s2">&quot;method&quot;</span> <span class="o">:</span> <span class="p">[</span> <span class="p">{</span>
     <span class="s2">&quot;title&quot;</span> <span class="o">:</span> <span class="s2">&quot;caspt2&quot;</span><span class="p">,</span>
       <span class="s2">&quot;smith&quot;</span> <span class="o">:</span> <span class="p">{</span>
         <span class="s2">&quot;method&quot;</span> <span class="o">:</span> <span class="s2">&quot;caspt2&quot;</span><span class="p">,</span>
         <span class="s2">&quot;ms&quot;</span> <span class="o">:</span> <span class="s2">&quot;true&quot;</span><span class="p">,</span>
         <span class="s2">&quot;xms&quot;</span> <span class="o">:</span> <span class="s2">&quot;true&quot;</span><span class="p">,</span>
         <span class="s2">&quot;sssr&quot;</span> <span class="o">:</span> <span class="s2">&quot;true&quot;</span><span class="p">,</span>
         <span class="s2">&quot;shift&quot;</span> <span class="o">:</span> <span class="mf">0.2</span><span class="p">,</span>
         <span class="s2">&quot;frozen&quot;</span> <span class="o">:</span> <span class="kc">true</span>
     <span class="p">},</span>
     <span class="s2">&quot;nstate&quot;</span> <span class="o">:</span> <span class="mi">2</span><span class="p">,</span>
     <span class="s2">&quot;nact&quot;</span> <span class="o">:</span> <span class="mi">3</span><span class="p">,</span>
     <span class="s2">&quot;nclosed&quot;</span> <span class="o">:</span> <span class="mi">46</span>
   <span class="p">}</span> <span class="p">]</span>
 <span class="p">}</span>
</pre></div>
</div>
</div>
<div class="section" id="sample-input-nacme-and-dgrad">
<h3>Sample input: NACME and DGRAD<a class="headerlink" href="#sample-input-nacme-and-dgrad" title="Permalink to this headline"></a></h3>
<div class="highlight-javascript"><div class="highlight"><pre><span></span><span class="p">{</span>
 <span class="s2">&quot;title&quot;</span> <span class="o">:</span> <span class="s2">&quot;nacme&quot;</span><span class="p">,</span>
   <span class="s2">&quot;target&quot;</span> <span class="o">:</span> <span class="mi">0</span><span class="p">,</span>
   <span class="s2">&quot;target2&quot;</span> <span class="o">:</span> <span class="mi">1</span><span class="p">,</span>
   <span class="s2">&quot;method&quot;</span> <span class="o">:</span> <span class="p">[</span> <span class="p">{</span>
     <span class="s2">&quot;title&quot;</span> <span class="o">:</span> <span class="s2">&quot;caspt2&quot;</span><span class="p">,</span>
       <span class="s2">&quot;smith&quot;</span> <span class="o">:</span> <span class="p">{</span>
         <span class="s2">&quot;method&quot;</span> <span class="o">:</span> <span class="s2">&quot;caspt2&quot;</span><span class="p">,</span>
         <span class="s2">&quot;ms&quot;</span> <span class="o">:</span> <span class="s2">&quot;true&quot;</span><span class="p">,</span>
         <span class="s2">&quot;xms&quot;</span> <span class="o">:</span> <span class="s2">&quot;true&quot;</span><span class="p">,</span>
         <span class="s2">&quot;sssr&quot;</span> <span class="o">:</span> <span class="s2">&quot;true&quot;</span><span class="p">,</span>
         <span class="s2">&quot;shift&quot;</span> <span class="o">:</span> <span class="mf">0.2</span><span class="p">,</span>
         <span class="s2">&quot;frozen&quot;</span> <span class="o">:</span> <span class="kc">true</span>
     <span class="p">},</span>
     <span class="s2">&quot;nstate&quot;</span> <span class="o">:</span> <span class="mi">3</span><span class="p">,</span>
     <span class="s2">&quot;nact&quot;</span> <span class="o">:</span> <span class="mi">7</span><span class="p">,</span>
     <span class="s2">&quot;nclosed&quot;</span> <span class="o">:</span> <span class="mi">44</span>
   <span class="p">}</span> <span class="p">]</span>
 <span class="p">}</span>
</pre></div>
</div>
<p>Using the keyword <code class="docutils literal"><span class="pre">forces</span></code>, you can run multiple gradient or derivative coupling calculations without repeating the energy calculations. The example below evaluates the nuclear gradient of the energy of the ground state, the first excited state, and the interstate coupling vector (<code class="docutils literal"><span class="pre">nacmtype</span></code> is <code class="docutils literal"><span class="pre">interstate</span></code>) between these two states.</p>
<div class="highlight-javascript"><div class="highlight"><pre><span></span><span class="p">{</span>
 <span class="s2">&quot;title&quot;</span> <span class="o">:</span> <span class="s2">&quot;forces&quot;</span><span class="p">,</span>
   <span class="s2">&quot;grads&quot;</span> <span class="o">:</span> <span class="p">[</span>
     <span class="p">{</span> <span class="s2">&quot;title&quot;</span> <span class="o">:</span> <span class="s2">&quot;force&quot;</span><span class="p">,</span> <span class="s2">&quot;target&quot;</span> <span class="o">:</span> <span class="mi">0</span> <span class="p">},</span>
     <span class="p">{</span> <span class="s2">&quot;title&quot;</span> <span class="o">:</span> <span class="s2">&quot;force&quot;</span><span class="p">,</span> <span class="s2">&quot;target&quot;</span> <span class="o">:</span> <span class="mi">1</span> <span class="p">},</span>
     <span class="p">{</span> <span class="s2">&quot;title&quot;</span> <span class="o">:</span> <span class="s2">&quot;nacme&quot;</span><span class="p">,</span> <span class="s2">&quot;target&quot;</span> <span class="o">:</span> <span class="mi">0</span><span class="p">,</span> <span class="s2">&quot;target2&quot;</span> <span class="o">:</span> <span class="mi">1</span><span class="p">,</span> <span class="s2">&quot;nacmtype&quot;</span> <span class="o">:</span> <span class="s2">&quot;interstate&quot;</span> <span class="p">}</span>
   <span class="p">],</span>
   <span class="s2">&quot;method&quot;</span> <span class="o">:</span> <span class="p">[</span> <span class="p">{</span>
     <span class="s2">&quot;title&quot;</span> <span class="o">:</span> <span class="s2">&quot;caspt2&quot;</span><span class="p">,</span>
       <span class="s2">&quot;smith&quot;</span> <span class="o">:</span> <span class="p">{</span>
         <span class="s2">&quot;method&quot;</span> <span class="o">:</span> <span class="s2">&quot;caspt2&quot;</span><span class="p">,</span>
         <span class="s2">&quot;ms&quot;</span> <span class="o">:</span> <span class="s2">&quot;true&quot;</span><span class="p">,</span>
         <span class="s2">&quot;xms&quot;</span> <span class="o">:</span> <span class="s2">&quot;true&quot;</span><span class="p">,</span>
         <span class="s2">&quot;sssr&quot;</span> <span class="o">:</span> <span class="s2">&quot;true&quot;</span><span class="p">,</span>
         <span class="s2">&quot;shift&quot;</span> <span class="o">:</span> <span class="mf">0.2</span><span class="p">,</span>
         <span class="s2">&quot;frozen&quot;</span> <span class="o">:</span> <span class="kc">true</span>
     <span class="p">},</span>
     <span class="s2">&quot;nstate&quot;</span> <span class="o">:</span> <span class="mi">3</span><span class="p">,</span>
     <span class="s2">&quot;nact&quot;</span> <span class="o">:</span> <span class="mi">7</span><span class="p">,</span>
     <span class="s2">&quot;nclosed&quot;</span> <span class="o">:</span> <span class="mi">44</span>
   <span class="p">}</span> <span class="p">]</span>
 <span class="p">}</span>
</pre></div>
</div>
</div>
<div class="section" id="sample-input-printing-relaxed-density">
<h3>Sample input: Printing relaxed density<a class="headerlink" href="#sample-input-printing-relaxed-density" title="Permalink to this headline"></a></h3>
<p>The relaxed density in MP2, SA-CASSCF, and CASPT2 gradient calculations can be printed in the Gaussian Cube format (<code class="docutils literal"><span class="pre">density.cub</span></code> file) by setting the keyword <code class="docutils literal"><span class="pre">density_print</span></code> to true
(see the example below).</p>
<div class="highlight-javascript"><div class="highlight"><pre><span></span><span class="p">{</span> <span class="s2">&quot;bagel&quot;</span> <span class="o">:</span> <span class="p">[</span>

<span class="p">{</span>
  <span class="s2">&quot;title&quot;</span> <span class="o">:</span> <span class="s2">&quot;molecule&quot;</span><span class="p">,</span>
  <span class="s2">&quot;basis&quot;</span> <span class="o">:</span> <span class="s2">&quot;svp&quot;</span><span class="p">,</span>
  <span class="s2">&quot;df_basis&quot;</span> <span class="o">:</span> <span class="s2">&quot;svp-jkfit&quot;</span><span class="p">,</span>
  <span class="s2">&quot;geometry&quot;</span> <span class="o">:</span> <span class="p">[</span>
    <span class="p">{</span> <span class="s2">&quot;atom&quot;</span> <span class="o">:</span> <span class="s2">&quot;Li&quot;</span><span class="p">,</span> <span class="s2">&quot;xyz&quot;</span> <span class="o">:</span> <span class="p">[</span> <span class="mf">0.000000</span><span class="p">,</span> <span class="mf">0.000000</span><span class="p">,</span> <span class="mf">6.000000</span><span class="p">]</span> <span class="p">},</span>
    <span class="p">{</span> <span class="s2">&quot;atom&quot;</span> <span class="o">:</span> <span class="s2">&quot;F&quot;</span><span class="p">,</span>  <span class="s2">&quot;xyz&quot;</span> <span class="o">:</span> <span class="p">[</span> <span class="mf">0.000000</span><span class="p">,</span> <span class="mf">0.000000</span><span class="p">,</span> <span class="mf">0.000000</span><span class="p">]</span> <span class="p">}</span>
  <span class="p">]</span>
<span class="p">},</span>

<span class="p">{</span>
  <span class="s2">&quot;title&quot;</span> <span class="o">:</span> <span class="s2">&quot;force&quot;</span><span class="p">,</span>
  <span class="s2">&quot;target&quot;</span> <span class="o">:</span> <span class="mi">0</span><span class="p">,</span>
  <span class="s2">&quot;density_print&quot;</span> <span class="o">:</span> <span class="kc">true</span><span class="p">,</span>
  <span class="s2">&quot;moprint&quot;</span> <span class="o">:</span> <span class="p">{</span>
    <span class="s2">&quot;inc_size&quot;</span> <span class="o">:</span> <span class="p">[</span> <span class="mf">0.20</span><span class="p">,</span> <span class="mf">0.20</span><span class="p">,</span> <span class="mf">0.20</span><span class="p">]</span>
  <span class="p">},</span>
  <span class="s2">&quot;method&quot;</span> <span class="o">:</span> <span class="p">[</span> <span class="p">{</span>
    <span class="s2">&quot;title&quot;</span> <span class="o">:</span> <span class="s2">&quot;caspt2&quot;</span><span class="p">,</span>
    <span class="s2">&quot;smith&quot;</span> <span class="o">:</span> <span class="p">{</span>
      <span class="s2">&quot;method&quot;</span> <span class="o">:</span> <span class="s2">&quot;caspt2&quot;</span><span class="p">,</span>
      <span class="s2">&quot;shift&quot;</span> <span class="o">:</span> <span class="mf">0.2</span><span class="p">,</span>
      <span class="s2">&quot;frozen&quot;</span> <span class="o">:</span> <span class="kc">true</span>
    <span class="p">},</span>
    <span class="s2">&quot;nstate&quot;</span> <span class="o">:</span> <span class="mi">4</span><span class="p">,</span>
    <span class="s2">&quot;nact&quot;</span> <span class="o">:</span> <span class="mi">4</span><span class="p">,</span>
    <span class="s2">&quot;nclosed&quot;</span> <span class="o">:</span> <span class="mi">3</span>
  <span class="p">}</span> <span class="p">]</span>
<span class="p">}</span>

<span class="p">]}</span>
</pre></div>
</div>
<p>Using the keyword <code class="docutils literal"><span class="pre">forces</span></code>, you can print multiple relaxed densities without repeating the energy calculations.
The example below prints all the XMS-CASPT2 relaxed densities.</p>
<div class="highlight-javascript"><div class="highlight"><pre><span></span><span class="p">{</span>
  <span class="s2">&quot;title&quot;</span> <span class="o">:</span> <span class="s2">&quot;forces&quot;</span><span class="p">,</span>
  <span class="s2">&quot;grads&quot;</span> <span class="o">:</span> <span class="p">[</span>
    <span class="p">{</span> <span class="s2">&quot;title&quot;</span> <span class="o">:</span> <span class="s2">&quot;force&quot;</span><span class="p">,</span> <span class="s2">&quot;target&quot;</span> <span class="o">:</span> <span class="mi">0</span><span class="p">,</span> <span class="s2">&quot;density_print&quot;</span> <span class="o">:</span> <span class="kc">true</span><span class="p">,</span> <span class="s2">&quot;moprint&quot;</span> <span class="o">:</span> <span class="p">{</span> <span class="s2">&quot;density_filename&quot;</span> <span class="o">:</span> <span class="s2">&quot;density_0&quot;</span> <span class="p">}</span> <span class="p">},</span>
    <span class="p">{</span> <span class="s2">&quot;title&quot;</span> <span class="o">:</span> <span class="s2">&quot;force&quot;</span><span class="p">,</span> <span class="s2">&quot;target&quot;</span> <span class="o">:</span> <span class="mi">1</span><span class="p">,</span> <span class="s2">&quot;density_print&quot;</span> <span class="o">:</span> <span class="kc">true</span><span class="p">,</span> <span class="s2">&quot;moprint&quot;</span> <span class="o">:</span> <span class="p">{</span> <span class="s2">&quot;density_filename&quot;</span> <span class="o">:</span> <span class="s2">&quot;density_1&quot;</span> <span class="p">}</span> <span class="p">},</span>
    <span class="p">{</span> <span class="s2">&quot;title&quot;</span> <span class="o">:</span> <span class="s2">&quot;force&quot;</span><span class="p">,</span> <span class="s2">&quot;target&quot;</span> <span class="o">:</span> <span class="mi">2</span><span class="p">,</span> <span class="s2">&quot;density_print&quot;</span> <span class="o">:</span> <span class="kc">true</span><span class="p">,</span> <span class="s2">&quot;moprint&quot;</span> <span class="o">:</span> <span class="p">{</span> <span class="s2">&quot;density_filename&quot;</span> <span class="o">:</span> <span class="s2">&quot;density_2&quot;</span> <span class="p">}</span> <span class="p">},</span>
    <span class="p">{</span> <span class="s2">&quot;title&quot;</span> <span class="o">:</span> <span class="s2">&quot;force&quot;</span><span class="p">,</span> <span class="s2">&quot;target&quot;</span> <span class="o">:</span> <span class="mi">3</span><span class="p">,</span> <span class="s2">&quot;density_print&quot;</span> <span class="o">:</span> <span class="kc">true</span><span class="p">,</span> <span class="s2">&quot;moprint&quot;</span> <span class="o">:</span> <span class="p">{</span> <span class="s2">&quot;density_filename&quot;</span> <span class="o">:</span> <span class="s2">&quot;density_3&quot;</span> <span class="p">}</span> <span class="p">}</span>
  <span class="p">],</span>
  <span class="s2">&quot;method&quot;</span> <span class="o">:</span> <span class="p">[</span> <span class="p">{</span>
    <span class="s2">&quot;title&quot;</span> <span class="o">:</span> <span class="s2">&quot;caspt2&quot;</span><span class="p">,</span>
    <span class="s2">&quot;smith&quot;</span> <span class="o">:</span> <span class="p">{</span>
      <span class="s2">&quot;method&quot;</span> <span class="o">:</span> <span class="s2">&quot;caspt2&quot;</span><span class="p">,</span>
      <span class="s2">&quot;ms&quot;</span> <span class="o">:</span> <span class="s2">&quot;true&quot;</span><span class="p">,</span>
      <span class="s2">&quot;xms&quot;</span> <span class="o">:</span> <span class="s2">&quot;true&quot;</span><span class="p">,</span>
      <span class="s2">&quot;sssr&quot;</span> <span class="o">:</span> <span class="s2">&quot;true&quot;</span><span class="p">,</span>
      <span class="s2">&quot;shift&quot;</span> <span class="o">:</span> <span class="mf">0.2</span><span class="p">,</span>
      <span class="s2">&quot;frozen&quot;</span> <span class="o">:</span> <span class="kc">true</span>
    <span class="p">},</span>
    <span class="s2">&quot;nstate&quot;</span> <span class="o">:</span> <span class="mi">4</span><span class="p">,</span>
    <span class="s2">&quot;nact&quot;</span> <span class="o">:</span> <span class="mi">4</span><span class="p">,</span>
    <span class="s2">&quot;nclosed&quot;</span> <span class="o">:</span> <span class="mi">3</span>
  <span class="p">}</span> <span class="p">]</span>
<span class="p">}</span>
</pre></div>
</div>
</div>
</div>
<div class="section" id="references">
<h2>References<a class="headerlink" href="#references" title="Permalink to this headline"></a></h2>
<div class="section" id="bagel-references">
<h3>BAGEL References<a class="headerlink" href="#bagel-references" title="Permalink to this headline"></a></h3>
<table border="1" class="docutils">
<colgroup>
<col width="37%" />
<col width="63%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Description of Reference</th>
<th class="head">Reference</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>SS-CASPT2 gradient</td>
<td>M. K. MacLeod and T. Shiozaki, J. Chem. Phys. <strong>142</strong>, 051103 (2015).</td>
</tr>
<tr class="row-odd"><td>(X)MS-CASPT2 gradient</td>
<td>B. Vlaisavljevich and T. Shiozaki, J. Chem. Theory Comput. <strong>12</strong>, 3781 (2016).</td>
</tr>
<tr class="row-even"><td>(X)MS-CASPT2 derivative coupling</td>
<td>J. W. Park and T. Shiozaki, J. Chem. Theory Comput. <strong>13</strong>, 2561 (2017).</td>
</tr>
<tr class="row-odd"><td>Current (X)MS-CASPT2 gradient algorithm</td>
<td>J. W. Park and T. Shiozaki, J. Chem. Theory Comput. <strong>13</strong>, 3676 (2017).</td>
</tr>
</tbody>
</table>
</div>
<div class="section" id="general-references">
<h3>General References<a class="headerlink" href="#general-references" title="Permalink to this headline"></a></h3>
<table border="1" class="docutils">
<colgroup>
<col width="37%" />
<col width="63%" />
</colgroup>
<thead valign="bottom">
<tr class="row-odd"><th class="head">Description of Reference</th>
<th class="head">Reference</th>
</tr>
</thead>
<tbody valign="top">
<tr class="row-even"><td>General review of gradient methods</td>
<td>P. Pulay, WIREs Comput. Mol. Sci. <strong>4</strong>, 169-181 (2014).</td>
</tr>
</tbody>
</table>
</div>
</div>
</div>


          </div>
        </div>
      </div>
      <div class="sphinxsidebar" role="navigation" aria-label="main navigation">
        <div class="sphinxsidebarwrapper">
<h3><a href="../index.html">Table Of Contents</a></h3>
<ul class="current">
<li class="toctree-l1 current"><a class="reference internal" href="../user-manual.html"><strong>BAGEL user manual</strong></a><ul class="current">
<li class="toctree-l2"><a class="reference internal" href="../quickstart/quickstart.html">First steps with BAGEL</a></li>
<li class="toctree-l2"><a class="reference internal" href="../molecule/molecule-toc.html">Molecule specification</a></li>
<li class="toctree-l2"><a class="reference internal" href="../scf/scf.html">Self-consistent field</a></li>
<li class="toctree-l2"><a class="reference internal" href="../ci/ci_methods.html">Configuration interaction</a></li>
<li class="toctree-l2"><a class="reference internal" href="../multi/multi.html">Multiconfiguration self-consistent field</a></li>
<li class="toctree-l2"><a class="reference internal" href="../pt2/pt2.html">Perturbation theory</a></li>
<li class="toctree-l2"><a class="reference internal" href="../smith/smith.html">SMITH3-generated code</a></li>
<li class="toctree-l2 current"><a class="reference internal" href="grad.html">Nuclear gradients and related functionalities</a></li>
<li class="toctree-l2"><a class="reference internal" href="../asd/asd.html">Active space decomposition method</a></li>
<li class="toctree-l2"><a class="reference internal" href="../miscellaneous/misc.html">Miscellaneous features</a></li>
<li class="toctree-l2"><a class="reference internal" href="../supp_info/supp_info.html">Supplementary information</a></li>
<li class="toctree-l2"><a class="reference internal" href="../author.html">Author contributions</a></li>
<li class="toctree-l2"><a class="reference internal" href="../funding.html">Funding and citation</a></li>
</ul>
</li>
</ul>

  <h4>Previous topic</h4>
  <p class="topless"><a href="methods.html"
                        title="previous chapter">Description of input structure</a></p>
  <h4>Next topic</h4>
  <p class="topless"><a href="../opt/optimize.html"
                        title="next chapter">Molecular geometry optimization</a></p>
<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="../opt/optimize.html" title="Molecular geometry optimization"
             >next</a></li>
        <li class="right" >
          <a href="methods.html" title="Description of input structure"
             >previous</a> |</li>
        <li class="nav-item nav-item-0"><a href="../index.html">BAGEL Manual</a> &#187;</li>
          <li class="nav-item nav-item-1"><a href="../user-manual.html" ><strong>BAGEL user manual</strong></a> &#187;</li>
          <li class="nav-item nav-item-2"><a href="grad.html" >Nuclear gradients and related functionalities</a> &#187;</li> 
      </ul>
    </div>
    <div class="footer" role="contentinfo">
        &#169; Copyright 2017, Shiozaki Group.
    </div>
  </body>
</html>