ASE Manual Release 3.6.1.2825 CAMd - CampOS Wiki

Use:
See Also:
eos = EquationOfState(volumes, energies, eos=’sjeos’)
v0, e0, B = eos.fit()
eos.plot()
The Equation of state tutorial.
7.26.2 Symmetry analysis
http://spglib.sourceforge.net/pyspglibForASE/
7.26.3 Phonons
http://phonopy.sourceforge.net/
7.27 Thermochemistry
ASE Manual, Release 3.6.1.2828
ASE contains a thermochemistry module that lets the user derive commonly desired thermodynamic quantities
from ASE output and some user-specified parameters. Two cases are currently handled by this module: the
ideal-gas limit (in which translational and rotational degrees of freedom are taken into account) and the harmonic
limit (generally used for adsorbates, in which all degrees of freedom are treated harmonically). Both cases rely on
good vibrational energies being fed to the calculators, which can be calculated with the vibrations module.
7.27.1 Ideal-gas limit
The thermodynamic quantities of ideal gases are calculated by assuming that all spatial degrees of freedom are separable
into translational, rotational, and vibrational degrees of freedom. The IdealGasThermo class supports
calculation of enthalpy (H), entropy (S), and free energy (G), and has the interface listed below.
class ase.thermochemistry.IdealGasThermo(vib_energies, geometry, electronicenergy=None,
atoms=None, symmetrynumber=None,
spin=None, natoms=None)
Class for calculating thermodynamic properties of a molecule based on statistical mechanical treatments in
the ideal gas approximation.
Inputs for enthalpy calculations:
vib_energies [list] a list of the vibrational energies of the molecule (e.g., from
ase.vibrations.Vibrations.get_energies). The number of vibrations used is automatically calculated
by the geometry and the number of atoms. If more are specified than are needed, then the lowest
numbered vibrations are neglected. If either atoms or natoms is unspecified, then uses the entire list.
Units are eV.
geometry [‘monatomic’, ‘linear’, or ‘nonlinear’] geometry of the molecule
electronicenergy [float] the electronic energy in eV (If electronicenergy is unspecified, then the methods
of this class can be interpreted as the enthalpy and free energy corrections.)
natoms [integer] the number of atoms, used along with ‘geometry’ to determine how many vibrations to
use. (Not needed if an atoms object is supplied in ‘atoms’ or if the user desires the entire list of
vibrations to be used.)
Extra inputs needed for for entropy / free energy calculations:
atoms [an ASE atoms object] used to calculate rotational moments of inertia and molecular mass
7.27. Thermochemistry 173