/usr/share/python-ase/doc/ase/units.rst is in python-ase-doc 3.12.0-2.
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 | .. module:: ase.units
=====
Units
=====
Physical units are defined in the :git:`ase/units.py` module. Electron volts
(``eV``) and angstroms (``Ang``) are defined as 1.0.
Other units are (amongst others)
``nm``, ``Bohr``, ``Hartree`` or ``Ha``, ``kJ``, ``kcal``, ``mol``,
``Rydberg`` or ``Ry``, ``second``, ``fs`` and ``kB``.
.. note::
As of version 3.12.0, all constants are taken from the 2014_
version of the CODATA suggestions. Before that, all constants were taken
from the 1986_ version. There is, however, a way to create all units
depending on other versions of CODATA via the :func:`create_units` function
(see Changing the CODATA version).
.. _1986: http://physics.nist.gov/cuu/Constants/archive1986.html
.. _2014: http://arxiv.org/pdf/1507.07956.pdf
Examples:
>>> from ase.units import *
>>> 2 * Bohr
1.0583545150138329
>>> 25 * Rydberg
340.14244569396635
>>> 100 * kJ/mol
1.0364272141304978
>>> 300 * kB
0.025852157076770025
>>> 0.1 * fs
0.009822693531550318
>>> print('1 Hartree =', Hartree * mol / kcal, 'kcal/mol')
1 Hartree = 627.50954059388 kcal/mol
Changing the CODATA version
---------------------------
If you just require an additional set of units that are based on a different
version of CODATA, you can use the ``create_units(codata_version)`` function.
It supports CODATA versions ``'1986'``, ``'1998'``, ``'2002'``, ``'2006'``,
``'2010'``, ``'2014'``. This function will return a dictionary with key-value
pairs of all the constants defined in the :mod:`ase.units` module, but based on
the CODATA version just selected:
>>> from ase.units import create_units
>>> units = create_units('1986')
>>> print(units['Bohr'])
0.5291772575069165
>>> units = create_units('2014')
>>> print(units['Bohr'])
0.5291772105638411
.. autofunction:: create_units
|