def test_get_U(self):
np.testing.assert_almost_equal(
self.CO2_pmutt.get_U(T=self.T0, V=self.V0, units='J/mol'),
-875.1095022368354 * c.R('J/mol/K') * self.T0)
np.testing.assert_almost_equal(
self.CO2_pmutt.get_U(T=self.T0, V=self.V0, units='J/g'),
-875.1095022368354 * c.R('J/mol/K') * self.T0 / self.mw)
def test_get_Cp(self):
np.testing.assert_almost_equal(
self.CO2_pmutt.get_Cp(T=self.T0, V=self.V0, units='J/mol/K'),
3.9422622359004853 * c.R('J/mol/K'))
np.testing.assert_almost_equal(
self.CO2_pmutt.get_Cp(T=self.T0, V=self.V0, units='J/g/K'),
3.9422622359004853 * c.R('J/mol/K') / self.mw)
def _fit_HoRT(T_ref, HoRT_ref, a, units):
"""Fit a[5] coefficient in a_low and a_high attributes given the
dimensionless enthalpy
Parameters
----------
T_ref : float
Reference temperature in K
HoRT_ref : float
Reference dimensionless enthalpy
T_mid : float
Temperature to fit the offset
units : str
Units corresponding to Shomate polynomial. Units should be supported
by :class:`~pmutt.constants.R`.
Returns
-------
a : (8,) `numpy.ndarray`_
Lower coefficients of Shomate polynomial
.. _`numpy.ndarray`: https://docs.scipy.org/doc/numpy/reference/generated/numpy.ndarray.html
"""
a[5] = (HoRT_ref \
- get_shomate_HoRT(T=np.array([T_ref]), a=a, units=units)) \
*c.R(units)*T_ref/c.prefixes['k']
a[7] = - get_shomate_HoRT(T=np.array([c.T0('K')]), a=a, units=units) \
*c.R(units)*c.T0('K')/c.prefixes['k']
return a
def test_get_F(self):
np.testing.assert_almost_equal(
self.CO2_pmutt.get_F(T=self.T0, V=self.V0, units='J/mol'),
-900.6031596134445 * c.R('J/mol/K') * self.T0)
np.testing.assert_almost_equal(
self.CO2_pmutt.get_F(T=self.T0, V=self.V0, units='J/g'),
-900.6031596134445 * c.R('J/mol/K') * self.T0 / self.mw)
def get_UoRT(self, T=c.T0('K'), **kwargs):
"""Calculates the dimensionless internal energy using the Extended LSR
relationship
Parameters
----------
T : float, optional
Temperature in K. Default is 298.15 K
kwargs : keyword arguments
Parameters to calculate reference binding energy, surface
energy and gas-phase energy
Returns
-------
UoRT : float
Dimensionless internal energy
"""
# Check if number of surface species, gas species, and reactions are
# consistent
n_reactions = len(self.reactions)
n_surf = len(self.surf_species)
n_gas = len(self.gas_species)
n_slopes = len(self.slopes)
if n_reactions != n_surf \
or n_reactions != n_gas \
or n_reactions != n_slopes:
warn_msg = (
'Extended LSR can an inconsistent number of slopes {} '
'reactions ({}), gas species ({}), and surface species '
'({}). Some contributions may be ignored.'
''.format(n_slopes, n_reactions, n_surf, n_gas))
warn(warn_msg)
kwargs['T'] = T
kwargs['units'] = 'kcal/mol'
UoRT = 0.
for slope, reaction, surf_species, gas_species in zip(
self.slopes, self.reactions, self.surf_species,
self.gas_species):
try:
deltaE_ref = reaction.get_delta_E(**kwargs)
except AttributeError:
deltaE_ref = reaction.get_delta_H(**kwargs)
# Calculate surface energy
try:
E_surf = surf_species.get_E(**kwargs)
except AttributeError:
E_surf = surf_species.get_H(**kwargs)
# Calculate gas-phase energy
try:
E_gas = gas_species.get_E(**kwargs)
except AttributeError:
E_gas = gas_species.get_H(**kwargs)
UoRT += (slope * deltaE_ref + E_surf +
E_gas) / c.R('kcal/mol/K') / T
return UoRT + self.intercept / c.R('kcal/mol/K') / T
def test_get_FoRT(self):
self.assertAlmostEqual(self.lsr_const.get_UoRT(),
4.5 / c.R('kcal/mol/K') / c.T0('K'),
places=2)
self.assertAlmostEqual(self.lsr_shomate.get_UoRT(),
4.5 / c.R('kcal/mol/K') / c.T0('K'),
places=2)
self.assertAlmostEqual(self.lsr_statmech.get_UoRT(),
4.5 / c.R('kcal/mol/K') / c.T0('K'),
places=2)
def test_get_E(self):
np.testing.assert_almost_equal(
self.CO2_pmutt.get_E(T=self.T0, units='J/mol'),
-894.97476277965 * c.R('J/mol/K') * self.T0)
np.testing.assert_almost_equal(self.CO2_pmutt.get_E(T=self.T0,
units='J/mol',
include_ZPE=True),
-877.703643641077 * c.R('J/mol/K') *
self.T0,
decimal=2)
def test_get_H(self):
T = np.array([
500., 525., 550., 575., 600., 625., 650., 675., 700., 725., 750.,
775., 800., 825., 850., 875., 900., 925., 950., 975., 1000., 1025.,
1050., 1075., 1100., 1125., 1150., 1175., 1200., 1225., 1250.,
1275., 1300., 1325., 1350., 1375., 1400., 1425., 1450., 1475.,
1500., 1525., 1550., 1575., 1600., 1625., 1650., 1675., 1700.
])
H_expected = np.array([
-56.50439376, -53.61125042, -50.97965343, -48.57545097,
-46.37018744, -44.3399637, -42.46456033, -40.72675589,
-39.11179131, -37.60694517, -36.20119391, -34.88493792,
-33.64977889, -32.48833779, -31.39410484, -30.36131539,
-29.38484627, -28.46012919, -27.58307762, -26.75002503,
-25.9576724, -25.20304335, -24.48344574, -23.79643859,
-23.13980357, -22.5115202, -21.90974438, -21.3327896, -20.77911052,
-20.2472886, -19.73601934, -19.24410116, -18.7704255, -18.31396799,
-17.87378072, -17.44898523, -17.03876635, -16.64236662,
-16.25908132, -15.88825401, -15.52927251, -15.18156522,
-14.84459794, -14.5178708, -14.20091565, -13.89329361,
-13.59459279, -13.30442637, -13.02243068
]) * c.R('J/mol/K') * T
np.testing.assert_almost_equal(self.Shomate_direct.get_H(
T=T[0], units='J/mol'),
H_expected[0],
decimal=4)
np.testing.assert_array_almost_equal(self.Shomate_direct.get_H(
T=T, units='J/mol'),
H_expected,
decimal=4)
def test_get_Cp(self):
T = np.array([
500., 525., 550., 575., 600., 625., 650., 675., 700., 725., 750.,
775., 800., 825., 850., 875., 900., 925., 950., 975., 1000., 1025.,
1050., 1075., 1100., 1125., 1150., 1175., 1200., 1225., 1250.,
1275., 1300., 1325., 1350., 1375., 1400., 1425., 1450., 1475.,
1500., 1525., 1550., 1575., 1600., 1625., 1650., 1675., 1700.
])
Cp_expected = np.array([
4.235796744, 4.267598139, 4.300310233, 4.333821197, 4.368036178,
4.402873306, 4.438260758, 4.474134568, 4.510436977, 4.547115164,
4.584120285, 4.621406707, 4.658931423, 4.696653576, 4.734534089,
4.772535363, 4.810621034, 4.848755777, 4.886905141, 4.925035419,
4.963113539, 5.001106966, 5.038983636, 5.07671188, 5.114260381,
5.151598119, 5.18869434, 5.225518516, 5.262040323, 5.298229611,
5.334056387, 5.369490794, 5.404503098, 5.439063673, 5.47314299,
5.506711603, 5.539740144, 5.572199316, 5.604059881, 5.635292657,
5.665868512, 5.695758359, 5.724933152, 5.753363882, 5.781021572,
5.807877279, 5.833902083, 5.859067093, 5.883343439
]) * c.R('J/mol/K')
np.testing.assert_almost_equal(
self.Shomate_direct.get_Cp(T=T[0], units='J/mol/K'),
Cp_expected[0])
np.testing.assert_array_almost_equal(
self.Shomate_direct.get_Cp(T=T, units='J/mol/K'), Cp_expected)
def get_UoRT(self, T=c.T0('K'), **kwargs):
"""Calculates the dimensionless internal energy using the LSR
relationship
Parameters
----------
T : float, optional
Temperature in K. Default is 298.15 K
kwargs : keyword arguments
Parameters to calculate reference binding energy, surface
energy and gas-phase energy
Returns
-------
UoRT : float
Dimensionless internal energy
"""
kwargs['T'] = T
kwargs['units'] = 'kcal/mol'
# Calculate reference binding energy
try:
deltaE_ref = self.reaction.get_delta_E(**kwargs)
except AttributeError:
deltaE_ref = self.reaction.get_delta_H(**kwargs)
# Calculate surface energy
try:
E_surf = self.surf_specie.get_E(**kwargs)
except AttributeError:
E_surf = self.surf_specie.get_H(**kwargs)
# Calculate gas-phase energy
try:
E_gas = self.gas_specie.get_E(**kwargs)
except AttributeError:
E_gas = self.gas_specie.get_H(**kwargs)
return (self.slope*deltaE_ref + self.intercept + E_surf + E_gas) \
/c.R('kcal/mol/K')/T
def get_Cp(self, T, units, raise_error=True, raise_warning=True, **kwargs):
"""Calculate the heat capacity
Parameters
----------
T : float or (N,) `numpy.ndarray`_
Temperature(s) in K
units : str
Units as string. See :func:`~pmutt.constants.R` for accepted
units.
raise_error : bool, optional
If True, raises an error if any of the modes do not have the
quantity of interest. Default is True
raise_warning : bool, optional
Only relevant if raise_error is False. Raises a warning if any
of the modes do not have the quantity of interest. Default is
True
kwargs : key-word arguments
Arguments to calculate mixture model properties, if any
Returns
-------
Cp : float or (N,) `numpy.ndarray`_
Heat capacity
.. _`numpy.ndarray`: https://docs.scipy.org/doc/numpy/reference/generated/numpy.ndarray.html
"""
return self.get_CpoR(T=T,
raise_error=raise_error,
raise_warning=raise_warning,
**kwargs) * c.R(units)
def test_get_S(self):
T = np.array([
500., 525., 550., 575., 600., 625., 650., 675., 700., 725., 750.,
775., 800., 825., 850., 875., 900., 925., 950., 975., 1000., 1025.,
1050., 1075., 1100., 1125., 1150., 1175., 1200., 1225., 1250.,
1275., 1300., 1325., 1350., 1375., 1400., 1425., 1450., 1475.,
1500., 1525., 1550., 1575., 1600., 1625., 1650., 1675., 1700.
])
S_expected = np.array([
24.84034743, 25.04777818, 25.24705859, 25.43895148, 25.62411782,
25.803134, 25.97650557, 26.14467824, 26.30804687, 26.46696281,
26.62173993, 26.77265968, 26.91997528, 27.06391529, 27.20468657,
27.34247693, 27.47745721, 27.60978326, 27.73959751, 27.86703041,
27.99220165, 28.11522125, 28.23619048, 28.35520273, 28.47234423,
28.58769466, 28.7013278, 28.81331199, 28.92371063, 29.03258257,
29.13998246, 29.24596116, 29.35056593, 29.45384082, 29.5558268,
29.6565621, 29.75608232, 29.85442065, 29.95160805, 30.04767338,
30.14264358, 30.23654374, 30.32939729, 30.42122603, 30.5120503,
30.60188904, 30.69075988, 30.77867922, 30.8656623
]) * c.R('J/mol/K')
np.testing.assert_almost_equal(
self.Shomate_direct.get_S(T=T[0], units='J/mol/K'), S_expected[0])
np.testing.assert_array_almost_equal(
self.Shomate_direct.get_S(T=T, units='J/mol/K'), S_expected)
np.testing.assert_almost_equal(
self.Shomate_direct.get_S(T=T[0], units='J/g/K'),
S_expected[0] / self.mw)
np.testing.assert_array_almost_equal(
self.Shomate_direct.get_S(T=T, units='J/g/K'),
S_expected / self.mw)
def test_get_G(self):
T = np.array([
500., 525., 550., 575., 600., 625., 650., 675., 700., 725., 750.,
775., 800., 825., 850., 875., 900., 925., 950., 975., 1000., 1025.,
1050., 1075., 1100., 1125., 1150., 1175., 1200., 1225., 1250.,
1275., 1300., 1325., 1350., 1375., 1400., 1425., 1450., 1475.,
1500., 1525., 1550., 1575., 1600., 1625., 1650., 1675., 1700.
])
G_expected = np.array([
-81.34474118, -78.6590286, -76.22671203, -74.01440245,
-71.99430526, -70.14309771, -68.4410659, -66.87143413,
-65.41983818, -64.07390798, -62.82293385, -61.6575976,
-60.56975418, -59.55225307, -58.59879142, -57.70379231,
-56.86230349, -56.06991246, -55.32267513, -54.61705544,
-53.94987405, -53.31826459, -52.71963622, -52.15164133,
-51.6121478, -51.09921486, -50.61107217, -50.14610159,
-49.70282116, -49.27987116, -48.8760018, -48.49006232,
-48.12099143, -47.76780881, -47.42960753, -47.10554734,
-46.79484867, -46.49678727, -46.21068937, -45.9359274,
-45.67191608, -45.41810897, -45.17399522, -44.93909682,
-44.71296595, -44.49518265, -44.28535267, -44.08310559,
-43.88809298
]) * c.R('J/mol/K') * T
np.testing.assert_almost_equal(self.Shomate_direct.get_G(
T=T[0], units='J/mol'),
G_expected[0],
decimal=4)
np.testing.assert_array_almost_equal(self.Shomate_direct.get_G(
T=T, units='J/mol'),
G_expected,
decimal=4)
def get_G_act(self, units, T, P=1., rev=False, **kwargs):
"""Calculates the Gibbs energy of activation. If there is no transition
state species, calculates the delta Gibbs energy
Parameters
----------
rev : bool, optional
Reverse direction. If True, uses products as initial state
instead of reactants. Default is False
T : float
Temperature in K
P : float, optional
Pressure in bar. Default is 1 bar
kwargs : keyword arguments
Parameters required to calculate enthalpy of activation.
Returns
-------
HoRT_act : float
Dimensionless activation enthalpy. Returns the max of the
following to ensure stable MKM performance:
- Difference between reactants/products and the transition state
- Difference between the reactants and the products
- 0
"""
R_units = '{}/K'.format(units)
return self.get_GoRT_act(rev=rev, T=T, P=P, **kwargs)*T*c.R(R_units)
def test_get_H(self):
T = np.array([
500., 600., 700., 800., 900., 1000., 1100., 1200., 1300., 1400.,
1500., 1600., 1700., 1800., 1900., 2000., 2100., 2200
])
H_expected = c.R('J/mol/K')*T *\
np.array([-56.49930957, -46.36612849, -39.10913137, -33.64819891,
-29.38377578, -25.95653237, -23.13812007, -20.77654898,
-18.76677584, -17.03389718, -15.52306522, -14.19318522,
-13.01283758, -11.95756475, -11.00803153, -10.14874498,
-9.367140366, -8.652916499])
np.testing.assert_almost_equal(self.Nasa_direct.get_H(T=T[0],
units='J/mol'),
H_expected[0],
decimal=4)
np.testing.assert_array_almost_equal(self.Nasa_direct.get_H(
T=T, units='J/mol'),
H_expected,
decimal=4)
np.testing.assert_almost_equal(self.Nasa_direct.get_H(T=T[0],
units='J/g'),
H_expected[0] / self.mw,
decimal=4)
np.testing.assert_array_almost_equal(self.Nasa_direct.get_H(
T=T, units='J/g'),
H_expected / self.mw,
decimal=4)
def get_shomate_SoR(a, T, units):
"""Calculates the dimensionless entropy using Shomate polynomial form
Parameters
----------
a : (8,) `numpy.ndarray`_
Coefficients of Shomate polynomial
T : iterable
Temperature in K
units : str
Units corresponding to Shomate polynomial. Units should be supported
by :class:`~pmutt.constants.R`.
Returns
-------
SoR : float
Dimensionless entropy
.. _`numpy.ndarray`: https://docs.scipy.org/doc/numpy/reference/generated/numpy.ndarray.html
"""
t = T / 1000.
t_arr = np.array(
[[np.log(x), x, x**2 / 2., x**3 / 3., -1. / 2. / x**2, 0., 1., 0.]
for x in t])
SoR = np.dot(t_arr, a) / c.R(units)
return SoR
def test_get_GoRT(self):
expected_GoRT_CO2 = \
self.CO2_ASE.get_gibbs_energy(temperature=self.T0,
pressure=self.P0,
verbose=False)/c.R('eV/K')/self.T0
calc_GoRT_CO2 = self.CO2_pmutt.get_GoRT(T=self.T0, V=self.V0)
np.testing.assert_almost_equal(expected_GoRT_CO2, calc_GoRT_CO2, 3)
def get_Vm(self, T=c.T0('K'), P=c.P0('bar'), gas_phase=True):
"""Calculates the molar volume of a van der Waals gas
Parameters
----------
T : float, optional
Temperature in K. Default is standard temperature
P : float, optional
Pressure in bar. Default is standard pressure
gas_phase : bool, optional
Relevant if system is in vapor-liquid equilibrium. If True,
return the larger volume (gas phase). If False, returns the
smaller volume (liquid phase).
Returns
-------
Vm : float
Volume in m3
"""
P_SI = P * c.convert_unit(initial='bar', final='Pa')
Vm = np.roots([
P_SI, -(P_SI * self.b + c.R('J/mol/K') * T), self.a,
-self.a * self.b
])
real_Vm = np.real([Vm_i for Vm_i in Vm if np.isreal(Vm_i)])
if gas_phase:
return np.max(real_Vm)
else:
return np.min(real_Vm)
def get_Tc(self):
"""Calculates the critical temperature
Returns
-------
Tc : float
Critcial temperature in K
"""
return 8. * self.a / 27. / self.b / c.R('J/mol/K')
def get_SoR(self):
"""Calculate the dimensionless entropy
Returns
-------
SoR : float
Dimensionless entropy
"""
return self.S / c.R('eV/K')
def get_CpoR(self):
"""Calculate the dimensionless heat capacity (constant pressure)
Returns
-------
CpoR : float
Dimensionless heat capacity (constant pressure)
"""
return self.Cp / c.R('eV/K')
def get_CvoR(self):
"""Calculate the dimensionless heat capacity (constant volume)
Returns
-------
CvoR : float
Dimensionless heat capacity (constant volume)
"""
return self.Cv / c.R('eV/K')
def from_critical(cls, Tc, Pc):
"""Creates the van der Waals object from critical temperature and
pressure
Parameters
----------
Tc : float
Critical temperature in K
Pc : float
Critical pressure in bar
Returns
-------
vanDerWaalsEOS : vanDerWaalsEOS object
"""
Pc_SI = Pc * c.convert_unit(initial='bar', final='Pa')
a = 27. / 64. * (c.R('J/mol/K') * Tc)**2 / Pc_SI
b = c.R('J/mol/K') * Tc / 8. / Pc_SI
return cls(a=a, b=b)
def units(self, val):
try:
c.R(val)
except KeyError:
err_msg = ('Units, "{}", inputted into pmutt.empirical.Shomate '
'object are invalid. See pmutt.constants.R for '
'supported units.'.format(val))
raise ValueError(err_msg)
else:
self._units = val
def get_GoRT_2D(self,
x1_name,
x1_values,
x2_name,
x2_values,
G_units=None,
**kwargs):
"""Calculates the Gibbs free energy for all the reactions for two
varying parameters
Parameters
----------
x1_name : str
Name of first variable to vary
x1_values : iterable object
x1 values to use
x2_name : str
Name of second variable to vary
x2_values : iterable object
x2 values to use
G_units : str, optional
Units for G. If None, uses GoRT. Default is None
kwargs : keyword arguments
Other variables to use in the calculation
Returns
-------
GoRT : (M, N, O) `numpy.ndarray`_ of float
GoRT values. The first index corresponds to the number of
reactions. The second index corresponds to the conditions
specified by x_values.
stable_phases : (N, O) `numpy.ndarray`_ of int
Each element of the array corresponds to the index of the most
stable phase at the x_values.
"""
GoRT = np.zeros(shape=(len(self.reactions), len(x1_values),
len(x2_values)))
for i, (reaction, norm_factor) in enumerate(
zip(self.reactions, self.norm_factors)):
for j, x1 in enumerate(x1_values):
kwargs[x1_name] = x1
for k, x2 in enumerate(x2_values):
kwargs[x2_name] = x2
GoRT[i, j, k] = \
reaction.get_delta_GoRT(**kwargs)/norm_factor
# Add unit corrections
if G_units is not None:
GoRT[i, j, k] *= c.R('{}/K'.format(G_units)) *\
kwargs['T']
# Take a transpose
GoRT_T = GoRT.transpose((1, 2, 0))
stable_phases = np.zeros((len(x1_values), len(x2_values)))
for i, GoRT_row in enumerate(GoRT_T):
stable_phases[i, :] = np.nanargmin(GoRT_row, axis=1)
return GoRT, stable_phases
def get_ZPE(self):
"""Calculate zero point energy
:math:`u^o_D = u^o +\\frac{9}{8}R\\Theta_D`
Returns
-------
zpe : float
Zero point energy in eV
"""
return self.interaction_energy \
+ 9./8.*c.R('eV/K')*self.debye_temperature
def get_GoRT(self, T=c.T0('K')):
"""Calculate the dimensionless Gibbs energy
Parameters
----------
T : float, optional
Temperature in K. Default is 298.15 K
Returns
-------
GoRT : float
Dimensionless Gibbs energy
"""
return self.G / c.R('eV/K') / T
def get_HoRT(self, T=c.T0('K')):
"""Calculate the dimensionless enthalpy
Parameters
----------
T : float, optional
Temperature in K. Default is 298.15 K
Returns
-------
HoRT : float
Dimensionless enthalpy
"""
return self.H / c.R('eV/K') / T
def test_get_S(self):
T = np.array([500., 600., 700., 800., 900., 1000., 1100., 1200.,
1300., 1400., 1500., 1600., 1700., 1800., 1900.,
2000., 2100., 2200])
S_expected = c.R('J/mol/K') *\
np.array([24.84583501, 25.62943045, 26.31248017, 26.92360771,
27.48073089, 27.99565652, 28.47647349, 28.92890014,
29.35709049, 29.76414079, 30.15242096, 30.52379873,
30.87979567, 31.22169282, 31.55059054, 31.86744523,
32.17309661, 32.46828858])
np.testing.assert_almost_equal(self.Nasa_direct.get_S(T=T[0], units='J/mol/K'),
S_expected[0])
np.testing.assert_array_almost_equal(self.Nasa_direct.get_S(T=T, units='J/mol/K'),
S_expected)
def test_get_Cp(self):
T = np.array([500., 600., 700., 800., 900., 1000., 1100., 1200.,
1300., 1400., 1500., 1600., 1700., 1800., 1900.,
2000., 2100., 2200])
Cp_expected = c.R('J/mol/K') *\
np.array([4.238636088, 4.363835667,
4.503924733, 4.654023202, 4.809813915, 4.967542636,
5.124018051, 5.276611768, 5.423258319, 5.56245516,
5.693262665, 5.815304137, 5.928750505, 6.034087273,
6.131819121, 6.222433488, 6.306400563, 6.384173277])
np.testing.assert_almost_equal(self.Nasa_direct.get_Cp(T=T[0], units='J/mol/K'),
Cp_expected[0])
np.testing.assert_array_almost_equal(self.Nasa_direct.get_Cp(T=T, units='J/mol/K'),
Cp_expected)
