def i_charge(self, i):
self._i_charge = check_return_property('i_charge', i)
if not self._i_charge:
if self.formula:
charge = charge_from_formula(self.formula)
chem_MW = molecular_weight(self.atoms)
i = charge/chem_MW * self.i_mass
self._i_charge = check_return_property('i_charge', i)
else: self._i_charge = 0.
def charge(self):
"""Charge of the species as an integer.
Computed as a property as most species do not have a charge and so
storing it would be a waste of memory.
"""
try:
return self._charge
except AttributeError:
self._charge = charge_from_formula(self.formula)
return self._charge
def test_Marcus_ion_conductivities():
# Check the CAS numbers are the "canonical" ones
assert all([CAS_from_any(i) == i for i in Marcus_ion_conductivities.index])
# Check the charges match up
for v, CAS in zip(Marcus_ion_conductivities['Charge'], Marcus_ion_conductivities.index):
assert v == charge_from_formula(pubchem_db.search_CAS(CAS).formula)
# Even check the formulas work!
for formula, CAS in zip(Marcus_ion_conductivities['Formula'], Marcus_ion_conductivities.index):
assert pubchem_db.search_CAS(CAS_from_any(formula)).CASs == CAS
def i_COD(self, i):
if i is not None: self._i_COD = check_return_property('i_COD', i)
else:
if self.organic or self.formula in ('H2', 'O2', 'N2', 'NO2-', 'NO3-'):
if self.measured_as == 'COD': self._i_COD = 1.
elif not self.atoms:
raise AttributeError(f"Must specify `i_COD` for organic component {self.ID}, "
f"which is not measured as COD and has no formula.")
else:
chem_MW = molecular_weight(self.atoms)
chem_charge = charge_from_formula(self.formula)
if self.formula in ('O2', 'N2', 'NO2-', 'NO3-'):
cod = electron_acceptor_cod(self.atoms, chem_charge) * molecular_weight({'O':2})
else:
Cr2O7 = - cod_test_stoichiometry(self.atoms, chem_charge)['Cr2O7-2']
cod = Cr2O7 * 1.5 * molecular_weight({'O':2})
self._i_COD = check_return_property('i_COD', cod/chem_MW * self.i_mass)
else: self._i_COD = 0.
def i_mass(self, i):
if self.atoms:
if i: raise AttributeError(f'Component {self.ID} has formula, i_mass '
f'is calculated, cannot be set.')
else:
if self.measured_as in self.atoms:
i = 1/get_mass_frac(self.atoms)[self.measured_as]
elif self.measured_as == 'COD':
chem_MW = molecular_weight(self.atoms)
chem_charge = charge_from_formula(self.formula)
Cr2O7 = - cod_test_stoichiometry(self.atoms, chem_charge)['Cr2O7-2']
cod = Cr2O7 * 1.5 * molecular_weight({'O':2})
i = chem_MW/cod
elif self.measured_as:
raise AttributeError(f'Must specify i_mass for component {self.ID} '
f'measured as {self.measured_as}.')
if self.measured_as == None:
if i and i != 1:
raise AttributeError(f'Component {self.ID} is measured as itself, '
f'i_mass cannot be set to values other than 1.')
i = 1
self._i_mass = check_return_property('i_mass', i)