pmutt.statmech.elec.GroundStateElec

class pmutt.statmech.elec.GroundStateElec(potentialenergy=None, spin=0.0, atoms=None, D0=None)

Bases: _ModelBase

Electronic modes using the ideal gas assumption. Equations sourced from:

Sandler, S. I. An Introduction to Applied Statistical Thermodynamics; John Wiley & Sons, 2010.

potentialenergy

Potential energy in eV. If this value and atoms are not specified, defaults to 0

Type:: float, optional

spin

The total electron spin. Default is 0

0 for molecules in which all electrons are paired
0.5 for a free radical with a single unpaired electron
1.0 for a triplet with two unpaired electrons, such as O ₂

Type:: float, optional

atoms

If potentialenergy is not specified, the energy will be obtained using atoms.get_potential_energy().

Type:: ase.Atoms object, optional

D0

Bond strength in eV. Preferentially used when calculating partition coefficient.

Type:: float, optional

__init__(potentialenergy=None, spin=0.0, atoms=None, D0=None)

Methods

`__init__`([potentialenergy, spin, atoms, D0])
`from_dict`(json_obj)	Recreate an object from the JSON representation.
`get_Cp`(units, **kwargs)	Calculate the heat capacity (constant P)
`get_CpoR`()	Calculates the dimensionless heat capacity at constant pressure
`get_Cv`(units, **kwargs)	Calculate the heat capacity (constant V)
`get_CvoR`()	Calculates the dimensionless heat capacity at constant volume
`get_F`(units[, T])	Calculate the Helmholtz energy
`get_FoRT`(T)	Calculates the dimensionless Helmholtz energy
`get_G`(units[, T])	Calculate the Gibbs energy
`get_GoRT`(T)	Calculates the dimensionless Gibbs energy
`get_H`(units[, T])	Calculate the enthalpy
`get_HoRT`(T)	Calculates the dimensionless enthalpy
`get_S`(units, **kwargs)	Calculate the entropy
`get_SoR`()	Calculates the dimensionless entropy
`get_U`(units[, T])	Calculate the internal energy
`get_UoRT`(T)	Calculates the imensionless internal energy
`get_q`(T[, ignore_q_elec])	Calculates the partition function
`to_dict`()	Represents object as dictionary with JSON-accepted datatypes

Attributes

spin

classmethod from_dict(json_obj)

Recreate an object from the JSON representation.

Parameters:: json_obj (dict) – JSON representation
Returns:: Obj
Return type:: Appropriate object

get_Cp(units, **kwargs)

Calculate the heat capacity (constant P)

Parameters:

units (str) – Units as string. See R() for accepted units.
kwargs (keyword arguments) – Parameters needed by get_CpoR

Returns:

Cp – Heat capacity (constant P) in appropriate units

Return type:

float

get_CpoR()

Calculates the dimensionless heat capacity at constant pressure

\(\frac{C_P^{elec}}{R}=\frac{C_V^{elec}}{R}=0\)

Returns:: CpoR_elec – Electronic dimensionless heat capacity at constant pressure
Return type:: float

get_Cv(units, **kwargs)

Calculate the heat capacity (constant V)

Parameters:

units (str) – Units as string. See R() for accepted units.
kwargs (keyword arguments) – Parameters needed by get_CvoR

Returns:

Cv – Heat capacity (constant V) in appropriate units

Return type:

float

get_CvoR()

Calculates the dimensionless heat capacity at constant volume

\(\frac{C_V^{elec}}{R}=0\)

Returns:: CvoR_elec – electronic dimensionless heat capacity at constant volume
Return type:: float

get_F(units, T=298.15, **kwargs)

Calculate the Helmholtz energy

Parameters:

units (str) – Units as string. See R() for accepted units but omit the ‘/K’ (e.g. J/mol).
T (float, optional) – Temperature in K. Default is 298.15 K
kwargs (keyword arguments) – Parameters needed by get_FoRT

Returns:

F – Hemholtz energy in appropriate units

Return type:

float

get_FoRT(T)

Calculates the dimensionless Helmholtz energy

\(\frac{A^{elec}}{RT}=\frac{U^{elec}}{RT}-\frac{S^{elec}}{R}\)

Parameters:: T (float) – Temperature in K
Returns:: FoRT_elec – Electronic dimensionless Helmholtz energy
Return type:: float

get_G(units, T=298.15, **kwargs)

Calculate the Gibbs energy

Parameters:

units (str) – Units as string. See R() for accepted units but omit the ‘/K’ (e.g. J/mol).
T (float, optional) – Temperature in K. Default is 298.15 K
kwargs (keyword arguments) – Parameters needed by get_GoRT

Returns:

G – Gibbs energy in appropriate units

Return type:

float

get_GoRT(T)

Calculates the dimensionless Gibbs energy

\(\frac{G^{elec}}{RT}=\frac{H^{elec}}{RT}-\frac{S^{elec}}{R}\)

Parameters:: T (float) – Temperature in K
Returns:: GoRT_elec – Electronic dimensionless Gibbs energy
Return type:: float

get_H(units, T=298.15, **kwargs)

Calculate the enthalpy

Parameters:

units (str) – Units as string. See R() for accepted units but omit the ‘/K’ (e.g. J/mol).
T (float, optional) – Temperature in K. Default is 298.15 K
kwargs (keyword arguments) – Parameters needed by get_HoRT

Returns:

H – Enthalpy in appropriate units

Return type:

float

get_HoRT(T)

Calculates the dimensionless enthalpy

\(\frac{H^{elec}}{RT}=\frac{U^{elec}}{RT}\)

Parameters:: T (float) – Temperature in K
Returns:: HoRT_elec – Electronic dimensionless enthalpy
Return type:: float

get_S(units, **kwargs)

Calculate the entropy

Parameters:

units (str) – Units as string. See R() for accepted units.
kwargs (keyword arguments) – Parameters needed by get_SoR

Returns:

S – Entropy in appropriate units

Return type:

float

get_SoR()

Calculates the dimensionless entropy

\(\frac{S^{elec}}{R}=\log \omega\)

Returns:: SoR_elec – Electronic dimensionless entropy
Return type:: float

get_U(units, T=298.15, **kwargs)

Calculate the internal energy

Parameters:

units (str) – Units as string. See R() for accepted units but omit the ‘/K’ (e.g. J/mol).
T (float, optional) – Temperature in K. Default is 298.15 K
kwargs (keyword arguments) – Parameters needed by get_UoRT

Returns:

U – Internal energy in appropriate units

Return type:

float

get_UoRT(T)

Calculates the imensionless internal energy

\(\frac{U^{elec}}{RT}=\frac{E}{RT}\)

Parameters:: T (float) – Temperature in K
Returns:: UoRT_elec – Electronic dimensionless internal energy
Return type:: float

get_q(T, ignore_q_elec=True)

Calculates the partition function

\(q^{elec}=1 + \omega_i \exp\bigg(-\frac{E}{RT}\bigg)\)

Parameters:

T (float) – Temperature in K
ignore_q_elec (bool, optional) – Ignore contribution of electronic mode to partition function . Often necessary since DFT’s value for potentialenergy is very negative causing q_elec to go to infinity. Default is True

Returns:

q_elec – Electronic partition function

Return type:

float

property spin

to_dict()

Represents object as dictionary with JSON-accepted datatypes

Returns:: obj_dict
Return type:: dict