def get_pourbaix_entries(self, chemsys):
"""
A helper function to get all entries necessary to generate
a pourbaix diagram from the rest interface.
Args:
chemsys ([str]): A list of elements comprising the chemical
system, e.g. ['Li', 'Fe']
"""
from pymatgen.analysis.pourbaix.entry import PourbaixEntry, IonEntry
from pymatgen.analysis.phase_diagram import PhaseDiagram
from pymatgen.core.ion import Ion
from pymatgen.entries.compatibility import\
MaterialsProjectAqueousCompatibility
chemsys = list(set(chemsys + ['O', 'H']))
entries = self.get_entries_in_chemsys(chemsys,
property_data=['e_above_hull'],
compatible_only=False)
compat = MaterialsProjectAqueousCompatibility("Advanced")
entries = compat.process_entries(entries)
solid_pd = PhaseDiagram(
entries) # Need this to get ion formation energy
url = '/pourbaix_diagram/reference_data/' + '-'.join(chemsys)
ion_data = self._make_request(url)
pbx_entries = []
for entry in entries:
if not set(entry.composition.elements)\
<= {Element('H'), Element('O')}:
pbx_entry = PourbaixEntry(entry)
pbx_entry.g0_replace(solid_pd.get_form_energy(entry))
pbx_entry.reduced_entry()
pbx_entries.append(pbx_entry)
# position the ion energies relative to most stable reference state
for n, i_d in enumerate(ion_data):
ion_entry = IonEntry(Ion.from_formula(i_d['Name']), i_d['Energy'])
refs = [
e for e in entries
if e.composition.reduced_formula == i_d['Reference Solid']
]
if not refs:
raise ValueError("Reference solid not contained in entry list")
stable_ref = sorted(refs, key=lambda x: x.data['e_above_hull'])[0]
rf = stable_ref.composition.get_reduced_composition_and_factor()[1]
solid_diff = solid_pd.get_form_energy(stable_ref)\
- i_d['Reference solid energy'] * rf
elt = i_d['Major_Elements'][0]
correction_factor = ion_entry.ion.composition[elt]\
/ stable_ref.composition[elt]
correction = solid_diff * correction_factor
pbx_entries.append(
PourbaixEntry(ion_entry, correction, 'ion-{}'.format(n)))
return pbx_entries
def get_pourbaix_entries(self, chemsys):
"""
A helper function to get all entries necessary to generate
a pourbaix diagram from the rest interface.
Args:
chemsys ([str]): A list of elements comprising the chemical
system, e.g. ['Li', 'Fe']
"""
from pymatgen.analysis.pourbaix.entry import PourbaixEntry, IonEntry
from pymatgen.analysis.phase_diagram import PhaseDiagram
from pymatgen.core.ion import Ion
from pymatgen.entries.compatibility import\
MaterialsProjectAqueousCompatibility
chemsys = list(set(chemsys + ['O', 'H']))
entries = self.get_entries_in_chemsys(
chemsys, property_data=['e_above_hull'], compatible_only=False)
compat = MaterialsProjectAqueousCompatibility("Advanced")
entries = compat.process_entries(entries)
solid_pd = PhaseDiagram(entries) # Need this to get ion formation energy
url = '/pourbaix_diagram/reference_data/' + '-'.join(chemsys)
ion_data = self._make_request(url)
pbx_entries = []
for entry in entries:
if not set(entry.composition.elements)\
<= {Element('H'), Element('O')}:
pbx_entry = PourbaixEntry(entry)
pbx_entry.g0_replace(solid_pd.get_form_energy(entry))
pbx_entry.reduced_entry()
pbx_entries.append(pbx_entry)
# position the ion energies relative to most stable reference state
for n, i_d in enumerate(ion_data):
ion_entry = IonEntry(Ion.from_formula(i_d['Name']), i_d['Energy'])
refs = [e for e in entries
if e.composition.reduced_formula == i_d['Reference Solid']]
if not refs:
raise ValueError("Reference solid not contained in entry list")
stable_ref = sorted(refs, key=lambda x: x.data['e_above_hull'])[0]
rf = stable_ref.composition.get_reduced_composition_and_factor()[1]
solid_diff = solid_pd.get_form_energy(stable_ref)\
- i_d['Reference solid energy'] * rf
elt = i_d['Major_Elements'][0]
correction_factor = ion_entry.ion.composition[elt]\
/ stable_ref.composition[elt]
correction = solid_diff * correction_factor
pbx_entries.append(PourbaixEntry(ion_entry, correction,
'ion-{}'.format(n)))
return pbx_entries
def test_get_ion_entries(self, mpr):
entries = mpr.get_entries_in_chemsys("Ti-O-H")
pd = PhaseDiagram(entries)
ion_entry_data = mpr.get_ion_reference_data_for_chemsys("Ti-O-H")
ion_entries = mpr.get_ion_entries(pd, ion_entry_data)
assert len(ion_entries) == 5
assert all([isinstance(i, IonEntry) for i in ion_entries])
# test an incomplete phase diagram
entries = mpr.get_entries_in_chemsys("Ti-O")
pd = PhaseDiagram(entries)
with pytest.raises(ValueError,
match="The phase diagram chemical system"):
mpr.get_ion_entries(pd)
# test ion energy calculation
ion_data = mpr.get_ion_reference_data_for_chemsys('S')
ion_ref_comps = [
Ion.from_formula(d["data"]["RefSolid"]).composition
for d in ion_data
]
ion_ref_elts = set(
itertools.chain.from_iterable(i.elements for i in ion_ref_comps))
ion_ref_entries = mpr.get_entries_in_chemsys(
list([str(e) for e in ion_ref_elts] + ["O", "H"]))
mpc = MaterialsProjectAqueousCompatibility()
ion_ref_entries = mpc.process_entries(ion_ref_entries)
ion_ref_pd = PhaseDiagram(ion_ref_entries)
ion_entries = mpr.get_ion_entries(ion_ref_pd, ion_ref_data=ion_data)
# In ion ref data, SO4-2 is -744.27 kJ/mol; ref solid is -1,279.0 kJ/mol
# so the ion entry should have an energy (-744.27 +1279) = 534.73 kJ/mol
# or 5.542 eV/f.u. above the energy of Na2SO4
so4_two_minus = [
e for e in ion_entries if e.ion.reduced_formula == "SO4[-2]"
][0]
# the ref solid is Na2SO4, ground state mp-4770
# the rf factor correction is necessary to make sure the composition
# of the reference solid is normalized to a single formula unit
ref_solid_entry = [
e for e in ion_ref_entries if e.entry_id == 'mp-4770'
][0]
rf = ref_solid_entry.composition.get_reduced_composition_and_factor(
)[1]
solid_energy = ion_ref_pd.get_form_energy(ref_solid_entry) / rf
assert np.allclose(so4_two_minus.energy,
solid_energy + 5.542,
atol=1e-3)
def get_pourbaix_entries(self, chemsys):
"""
A helper function to get all entries necessary to generate
a pourbaix diagram from the rest interface.
Args:
chemsys ([str]): A list of elements comprising the chemical
system, e.g. ['Li', 'Fe']
"""
from pymatgen.analysis.pourbaix_diagram import PourbaixEntry, IonEntry
from pymatgen.analysis.phase_diagram import PhaseDiagram
from pymatgen.core.ion import Ion
from pymatgen.entries.compatibility import\
MaterialsProjectAqueousCompatibility
pbx_entries = []
# Get ion entries first, because certain ions have reference
# solids that aren't necessarily in the chemsys (Na2SO4)
url = '/pourbaix_diagram/reference_data/' + '-'.join(chemsys)
ion_data = self._make_request(url)
ion_ref_comps = [Composition(d['Reference Solid']) for d in ion_data]
ion_ref_elts = list(itertools.chain.from_iterable(
i.elements for i in ion_ref_comps))
ion_ref_entries = self.get_entries_in_chemsys(
list(set([str(e) for e in ion_ref_elts] + ['O', 'H'])),
property_data=['e_above_hull'], compatible_only=False)
compat = MaterialsProjectAqueousCompatibility("Advanced")
ion_ref_entries = compat.process_entries(ion_ref_entries)
ion_ref_pd = PhaseDiagram(ion_ref_entries)
# position the ion energies relative to most stable reference state
for n, i_d in enumerate(ion_data):
ion_entry = IonEntry(Ion.from_formula(i_d['Name']), i_d['Energy'])
refs = [e for e in ion_ref_entries
if e.composition.reduced_formula == i_d['Reference Solid']]
if not refs:
raise ValueError("Reference solid not contained in entry list")
stable_ref = sorted(refs, key=lambda x: x.data['e_above_hull'])[0]
rf = stable_ref.composition.get_reduced_composition_and_factor()[1]
solid_diff = ion_ref_pd.get_form_energy(stable_ref)\
- i_d['Reference solid energy'] * rf
elt = i_d['Major_Elements'][0]
correction_factor = ion_entry.ion.composition[elt]\
/ stable_ref.composition[elt]
ion_entry.energy += solid_diff * correction_factor
pbx_entries.append(PourbaixEntry(ion_entry, 'ion-{}'.format(n)))
# import nose; nose.tools.set_trace()
# Construct the solid pourbaix entries from filtered ion_ref entries
extra_elts = set(ion_ref_elts) - {Element(s) for s in chemsys}\
- {Element('H'), Element('O')}
for entry in ion_ref_entries:
entry_elts = set(entry.composition.elements)
# Ensure no OH chemsys or extraneous elements from ion references
if not (entry_elts <= {Element('H'), Element('O')} or \
extra_elts.intersection(entry_elts)):
# replace energy with formation energy, use dict to
# avoid messing with the ion_ref_pd and to keep all old params
form_e = ion_ref_pd.get_form_energy(entry)
new_entry = deepcopy(entry)
new_entry.uncorrected_energy = form_e
new_entry.correction = 0.0
pbx_entry = PourbaixEntry(new_entry)
if entry.entry_id == "mp-697146":
pass
# import nose; nose.tools.set_trace()
# pbx_entry.reduced_entry()
pbx_entries.append(pbx_entry)
return pbx_entries
def get_pourbaix_entries(
self,
chemsys: Union[str, List],
solid_compat="MaterialsProject2020Compatibility",
use_gibbs: Optional[Literal[300]] = None,
):
"""
A helper function to get all entries necessary to generate
a Pourbaix diagram from the rest interface.
Args:
chemsys (str or [str]): Chemical system string comprising element
symbols separated by dashes, e.g., "Li-Fe-O" or List of element
symbols, e.g., ["Li", "Fe", "O"].
solid_compat: Compatiblity scheme used to pre-process solid DFT energies prior
to applying aqueous energy adjustments. May be passed as a class (e.g.
MaterialsProject2020Compatibility) or an instance
(e.g., MaterialsProject2020Compatibility()). If None, solid DFT energies
are used as-is. Default: MaterialsProject2020Compatibility
use_gibbs: Set to 300 (for 300 Kelvin) to use a machine learning model to
estimate solid free energy from DFT energy (see GibbsComputedStructureEntry).
This can slightly improve the accuracy of the Pourbaix diagram in some
cases. Default: None. Note that temperatures other than 300K are not
permitted here, because MaterialsProjectAqueousCompatibility corrections,
used in Pourbaix diagram construction, are calculated based on 300 K data.
"""
# imports are not top-level due to expense
from pymatgen.analysis.pourbaix_diagram import PourbaixEntry
from pymatgen.entries.compatibility import (
Compatibility,
MaterialsProject2020Compatibility,
MaterialsProjectAqueousCompatibility,
MaterialsProjectCompatibility,
)
from pymatgen.entries.computed_entries import ComputedEntry
if solid_compat == "MaterialsProjectCompatibility":
solid_compat = MaterialsProjectCompatibility()
elif solid_compat == "MaterialsProject2020Compatibility":
solid_compat = MaterialsProject2020Compatibility()
elif isinstance(solid_compat, Compatibility):
solid_compat = solid_compat
else:
raise ValueError(
"Solid compatibility can only be 'MaterialsProjectCompatibility', "
"'MaterialsProject2020Compatibility', or an instance of a Compatability class"
)
pbx_entries = []
if isinstance(chemsys, str):
chemsys = chemsys.split("-")
# capitalize and sort the elements
chemsys = sorted(e.capitalize() for e in chemsys)
# Get ion entries first, because certain ions have reference
# solids that aren't necessarily in the chemsys (Na2SO4)
# download the ion reference data from MPContribs
ion_data = self.get_ion_reference_data_for_chemsys(chemsys)
# build the PhaseDiagram for get_ion_entries
ion_ref_comps = [
Ion.from_formula(d["data"]["RefSolid"]).composition
for d in ion_data
]
ion_ref_elts = set(
itertools.chain.from_iterable(i.elements for i in ion_ref_comps))
# TODO - would be great if the commented line below would work
# However for some reason you cannot process GibbsComputedStructureEntry with
# MaterialsProjectAqueousCompatibility
ion_ref_entries = self.get_entries_in_chemsys(
list([str(e) for e in ion_ref_elts] + ["O", "H"]),
# use_gibbs=use_gibbs
)
# suppress the warning about supplying the required energies; they will be calculated from the
# entries we get from MPRester
with warnings.catch_warnings():
warnings.filterwarnings(
"ignore",
message="You did not provide the required O2 and H2O energies.",
)
compat = MaterialsProjectAqueousCompatibility(
solid_compat=solid_compat)
# suppress the warning about missing oxidation states
with warnings.catch_warnings():
warnings.filterwarnings(
"ignore", message="Failed to guess oxidation states.*")
ion_ref_entries = compat.process_entries(ion_ref_entries)
# TODO - if the commented line above would work, this conditional block
# could be removed
if use_gibbs:
# replace the entries with GibbsComputedStructureEntry
from pymatgen.entries.computed_entries import GibbsComputedStructureEntry
ion_ref_entries = GibbsComputedStructureEntry.from_entries(
ion_ref_entries, temp=use_gibbs)
ion_ref_pd = PhaseDiagram(ion_ref_entries)
ion_entries = self.get_ion_entries(ion_ref_pd, ion_ref_data=ion_data)
pbx_entries = [
PourbaixEntry(e, f"ion-{n}") for n, e in enumerate(ion_entries)
]
# Construct the solid pourbaix entries from filtered ion_ref entries
extra_elts = (set(ion_ref_elts) - {Element(s)
for s in chemsys} -
{Element("H"), Element("O")})
for entry in ion_ref_entries:
entry_elts = set(entry.composition.elements)
# Ensure no OH chemsys or extraneous elements from ion references
if not (entry_elts <= {Element("H"), Element("O")}
or extra_elts.intersection(entry_elts)):
# Create new computed entry
form_e = ion_ref_pd.get_form_energy(entry)
new_entry = ComputedEntry(entry.composition,
form_e,
entry_id=entry.entry_id)
pbx_entry = PourbaixEntry(new_entry)
pbx_entries.append(pbx_entry)
return pbx_entries
def get_pourbaix_entries(self, chemsys):
"""
A helper function to get all entries necessary to generate
a pourbaix diagram from the rest interface.
Args:
chemsys ([str]): A list of elements comprising the chemical
system, e.g. ['Li', 'Fe']
"""
from pymatgen.analysis.pourbaix_diagram import PourbaixEntry, IonEntry
from pymatgen.analysis.phase_diagram import PhaseDiagram
from pymatgen.core.ion import Ion
from pymatgen.entries.compatibility import\
MaterialsProjectAqueousCompatibility
pbx_entries = []
# Get ion entries first, because certain ions have reference
# solids that aren't necessarily in the chemsys (Na2SO4)
url = '/pourbaix_diagram/reference_data/' + '-'.join(chemsys)
ion_data = self._make_request(url)
ion_ref_comps = [Composition(d['Reference Solid']) for d in ion_data]
ion_ref_elts = list(itertools.chain.from_iterable(
i.elements for i in ion_ref_comps))
ion_ref_entries = self.get_entries_in_chemsys(
list(set([str(e) for e in ion_ref_elts] + ['O', 'H'])),
property_data=['e_above_hull'], compatible_only=False)
compat = MaterialsProjectAqueousCompatibility("Advanced")
ion_ref_entries = compat.process_entries(ion_ref_entries)
ion_ref_pd = PhaseDiagram(ion_ref_entries)
# position the ion energies relative to most stable reference state
for n, i_d in enumerate(ion_data):
ion_entry = IonEntry(Ion.from_formula(i_d['Name']), i_d['Energy'])
refs = [e for e in ion_ref_entries
if e.composition.reduced_formula == i_d['Reference Solid']]
if not refs:
raise ValueError("Reference solid not contained in entry list")
stable_ref = sorted(refs, key=lambda x: x.data['e_above_hull'])[0]
rf = stable_ref.composition.get_reduced_composition_and_factor()[1]
solid_diff = ion_ref_pd.get_form_energy(stable_ref)\
- i_d['Reference solid energy'] * rf
elt = i_d['Major_Elements'][0]
correction_factor = ion_entry.ion.composition[elt]\
/ stable_ref.composition[elt]
ion_entry.energy += solid_diff * correction_factor
pbx_entries.append(PourbaixEntry(ion_entry, 'ion-{}'.format(n)))
# import nose; nose.tools.set_trace()
# Construct the solid pourbaix entries from filtered ion_ref entries
extra_elts = set(ion_ref_elts) - {Element(s) for s in chemsys}\
- {Element('H'), Element('O')}
for entry in ion_ref_entries:
entry_elts = set(entry.composition.elements)
# Ensure no OH chemsys or extraneous elements from ion references
if not (entry_elts <= {Element('H'), Element('O')} or \
extra_elts.intersection(entry_elts)):
# replace energy with formation energy, use dict to
# avoid messing with the ion_ref_pd and to keep all old params
form_e = ion_ref_pd.get_form_energy(entry)
new_entry = deepcopy(entry)
new_entry.uncorrected_energy = form_e
new_entry.correction = 0.0
pbx_entry = PourbaixEntry(new_entry)
if entry.entry_id == "mp-697146":
pass
# import nose; nose.tools.set_trace()
# pbx_entry.reduced_entry()
pbx_entries.append(pbx_entry)
return pbx_entries