def setUp(self):
entrylist = list()
weights = list()
comp = Composition("Mn2O3")
entry = PDEntry(comp, 49)
entrylist.append(PourbaixEntry(entry))
weights.append(1.0)
comp = Ion.from_formula("MnO4[-]")
entry = IonEntry(comp, 25)
entrylist.append(PourbaixEntry(entry))
weights.append(0.25)
comp = Composition("Fe2O3")
entry = PDEntry(comp, 50)
entrylist.append(PourbaixEntry(entry))
weights.append(0.5)
comp = Ion.from_formula("Fe[2+]")
entry = IonEntry(comp, 15)
entrylist.append(PourbaixEntry(entry))
weights.append(2.5)
comp = Ion.from_formula("Fe[3+]")
entry = IonEntry(comp, 20)
entrylist.append(PourbaixEntry(entry))
weights.append(1.5)
self.weights = weights
self.entrylist = entrylist
self.multientry = MultiEntry(entrylist, weights)
def setUp(self):
entrylist = list()
weights = list()
comp = Composition("Mn2O3")
entry = PDEntry(comp, 49)
entrylist.append(PourbaixEntry(entry))
weights.append(1.0)
comp = Ion.from_formula("MnO4[-]")
entry = IonEntry(comp, 25)
entrylist.append(PourbaixEntry(entry))
weights.append(0.25)
comp = Composition("Fe2O3")
entry = PDEntry(comp, 50)
entrylist.append(PourbaixEntry(entry))
weights.append(0.5)
comp = Ion.from_formula("Fe[2+]")
entry = IonEntry(comp, 15)
entrylist.append(PourbaixEntry(entry))
weights.append(2.5)
comp = Ion.from_formula("Fe[3+]")
entry = IonEntry(comp, 20)
entrylist.append(PourbaixEntry(entry))
weights.append(1.5)
self.weights = weights
self.entrylist = entrylist
self.multientry = MultiEntry(entrylist, weights)
def test_init_(self):
c = Composition({'Fe': 4, 'O': 16, 'P': 4})
charge = 4
self.assertEqual("Fe4 P4 O16 +4", Ion(c, charge).formula)
f = {1: 1, 8: 1}
charge = -1
self.assertEqual("H1 O1 -1", Ion(Composition(f), charge).formula)
self.assertEqual("S2 O3 -2", Ion(Composition(S=2, O=3), -2).formula)
def setUp(self):
self.comp = list()
self.comp.append(Ion.from_formula("Li+"))
self.comp.append(Ion.from_formula("MnO4-"))
self.comp.append(Ion.from_formula("Mn++"))
self.comp.append(Ion.from_formula("PO3-2"))
self.comp.append(Ion.from_formula("Fe(CN)6-3"))
self.comp.append(Ion.from_formula("Fe(CN)6----"))
self.comp.append(Ion.from_formula("Fe2((PO4)3(CO3)5)2-3"))
self.comp.append(Ion.from_formula("Ca[2+]"))
self.comp.append(Ion.from_formula("NaOH(aq)"))
def setUp(self):
self.comp = list()
self.comp.append(Ion.from_formula("Li+"))
self.comp.append(Ion.from_formula("MnO4-"))
self.comp.append(Ion.from_formula("Mn++"))
self.comp.append(Ion.from_formula("PO3-2"))
self.comp.append(Ion.from_formula("Fe(CN)6-3"))
self.comp.append(Ion.from_formula("Fe(CN)6----"))
self.comp.append(Ion.from_formula("Fe2((PO4)3(CO3)5)2-3"))
self.comp.append(Ion.from_formula("Ca[2+]"))
self.comp.append(Ion.from_formula("NaOH(aq)"))
def len_elts(entry):
if "(s)" in entry:
comp = Composition(entry[:-3])
else:
comp = Ion.from_formula(entry)
return len([el for el in comp.elements if el not in
[Element("H"), Element("O")]])
def from_dict(cls, d):
"""
Returns an IonEntry object from a dict.
"""
return IonEntry(
Ion.from_dict(d["ion"]), d["energy"], d.get("name"), d.get("attribute")
)
def test_mpr_pipeline(self):
from pymatgen.ext.matproj import MPRester
mpr = MPRester()
data = mpr.get_pourbaix_entries(["Zn"])
pbx = PourbaixDiagram(data, filter_solids=True, conc_dict={"Zn": 1e-8})
pbx.find_stable_entry(10, 0)
data = mpr.get_pourbaix_entries(["Ag", "Te"])
pbx = PourbaixDiagram(data, filter_solids=True, conc_dict={"Ag": 1e-8, "Te": 1e-8})
self.assertEqual(len(pbx.stable_entries), 30)
test_entry = pbx.find_stable_entry(8, 2)
self.assertAlmostEqual(test_entry.energy, 2.3894017960000009, 1)
# Test custom ions
entries = mpr.get_pourbaix_entries(["Sn", "C", "Na"])
ion = IonEntry(Ion.from_formula("NaO28H80Sn12C24+"), -161.676)
custom_ion_entry = PourbaixEntry(ion, entry_id="my_ion")
pbx = PourbaixDiagram(
entries + [custom_ion_entry],
filter_solids=True,
comp_dict={"Na": 1, "Sn": 12, "C": 24},
)
self.assertAlmostEqual(pbx.get_decomposition_energy(custom_ion_entry, 5, 2), 2.1209002582, 1)
# Test against ion sets with multiple equivalent ions (Bi-V regression)
entries = mpr.get_pourbaix_entries(["Bi", "V"])
pbx = PourbaixDiagram(entries, filter_solids=True, conc_dict={"Bi": 1e-8, "V": 1e-8})
self.assertTrue(all(["Bi" in entry.composition and "V" in entry.composition for entry in pbx.all_entries]))
def test_from_dict(self):
sym_dict = {"P": 1, "O": 4, "charge": -2}
self.assertEqual(
Ion.from_dict(sym_dict).reduced_formula,
"PO4[-2]",
"Creation form sym_amount dictionary failed!",
)
def test_mpr_pipeline(self):
from pymatgen import MPRester
mpr = MPRester()
data = mpr.get_pourbaix_entries(["Zn"])
pbx = PourbaixDiagram(data, filter_solids=True, conc_dict={"Zn": 1e-8})
pbx.find_stable_entry(10, 0)
data = mpr.get_pourbaix_entries(["Ag", "Te"])
pbx = PourbaixDiagram(data,
filter_solids=True,
conc_dict={
"Ag": 1e-8,
"Te": 1e-8
})
self.assertEqual(len(pbx.stable_entries), 30)
test_entry = pbx.find_stable_entry(8, 2)
self.assertAlmostEqual(test_entry.energy, 2.3936747835000016, 3)
# Test custom ions
entries = mpr.get_pourbaix_entries(["Sn", "C", "Na"])
ion = IonEntry(Ion.from_formula("NaO28H80Sn12C24+"), -161.676)
custom_ion_entry = PourbaixEntry(ion, entry_id='my_ion')
pbx = PourbaixDiagram(entries + [custom_ion_entry],
filter_solids=True,
comp_dict={
"Na": 1,
"Sn": 12,
"C": 24
})
self.assertAlmostEqual(
pbx.get_decomposition_energy(custom_ion_entry, 5, 2),
8.31202738629504, 2)
def test_read_write_csv(self):
Zn_solids = ["Zn", "ZnO", "ZnO2"]
sol_g = [0.0, -3.338, -1.315]
Zn_ions = ["Zn[2+]", "ZnOH[+]", "HZnO2[-]", "ZnO2[2-]", "ZnO"]
liq_g = [-1.527, -3.415, -4.812, -4.036, -2.921]
liq_conc = [1e-6, 1e-6, 1e-6, 1e-6, 1e-6]
solid_entry = list()
for sol in Zn_solids:
comp = Composition(sol)
delg = sol_g[Zn_solids.index(sol)]
solid_entry.append(PourbaixEntry(PDEntry(comp, delg)))
ion_entry = list()
for ion in Zn_ions:
comp_ion = Ion.from_formula(ion)
delg = liq_g[Zn_ions.index(ion)]
conc = liq_conc[Zn_ions.index(ion)]
PoE = PourbaixEntry(IonEntry(comp_ion, delg))
PoE.set_conc(conc)
ion_entry.append(PoE)
entries = solid_entry + ion_entry
PourbaixEntryIO.to_csv("pourbaix_test_entries.csv", entries)
(elements, entries) = PourbaixEntryIO.from_csv(
"pourbaix_test_entries.csv")
self.assertEqual(elements,
[Element('Zn'), Element('H'), Element('O')],
"Wrong elements!")
self.assertEqual(len(entries), 8, "Wrong number of entries!")
os.remove("pourbaix_test_entries.csv")
def test_read_write_csv(self):
Zn_solids = ["Zn", "ZnO", "ZnO2"]
sol_g = [0.0, -3.338, -1.315]
Zn_ions = ["Zn[2+]", "ZnOH[+]", "HZnO2[-]", "ZnO2[2-]", "ZnO"]
liq_g = [-1.527, -3.415, -4.812, -4.036, -2.921]
liq_conc = [1e-6, 1e-6, 1e-6, 1e-6, 1e-6]
solid_entry = list()
for sol in Zn_solids:
comp = Composition(sol)
delg = sol_g[Zn_solids.index(sol)]
solid_entry.append(PourbaixEntry(PDEntry(comp, delg)))
ion_entry = list()
for ion in Zn_ions:
comp_ion = Ion.from_formula(ion)
delg = liq_g[Zn_ions.index(ion)]
conc = liq_conc[Zn_ions.index(ion)]
PoE = PourbaixEntry(IonEntry(comp_ion, delg))
PoE.conc = conc
ion_entry.append(PoE)
entries = solid_entry + ion_entry
PourbaixEntryIO.to_csv("pourbaix_test_entries.csv", entries)
(elements,
entries) = PourbaixEntryIO.from_csv("pourbaix_test_entries.csv")
self.assertEqual(
elements, [Element('Zn'),
Element('H'), Element('O')], "Wrong elements!")
self.assertEqual(len(entries), 8, "Wrong number of entries!")
os.remove("pourbaix_test_entries.csv")
def len_elts(entry):
if "(s)" in entry:
comp = Composition(entry[:-3])
else:
comp = Ion.from_formula(entry)
return len([el for el in comp.elements if el not in
[Element("H"), Element("O")]])
def setUp(self):
# comp = Composition("Mn2O3")
self.solentry = ComputedEntry("Mn2O3", 49)
ion = Ion.from_formula("MnO4-")
self.ionentry = IonEntry(ion, 25)
self.PxIon = PourbaixEntry(self.ionentry)
self.PxSol = PourbaixEntry(self.solentry)
self.PxIon.concentration = 1e-4
def setUp(self):
comp = Composition("Mn2O3")
self.solentry = PDEntry(comp, 49)
ion = Ion.from_formula("MnO4-")
self.ionentry = IonEntry(ion, 25)
self.PxIon = PourbaixEntry(self.ionentry)
self.PxSol = PourbaixEntry(self.solentry)
self.PxIon.conc = 1e-4
def setUp(self):
# comp = Composition("Mn2O3")
self.solentry = ComputedEntry("Mn2O3", 49)
ion = Ion.from_formula("MnO4-")
self.ionentry = IonEntry(ion, 25)
self.PxIon = PourbaixEntry(self.ionentry)
self.PxSol = PourbaixEntry(self.solentry)
self.PxIon.concentration = 1e-4
def test_equals(self):
random_z = random.randint(1, 92)
fixed_el = Element.from_Z(random_z)
other_z = random.randint(1, 92)
while other_z == random_z:
other_z = random.randint(1, 92)
comp1 = Ion(Composition({fixed_el: 1, Element.from_Z(other_z): 0}), 1)
other_z = random.randint(1, 92)
while other_z == random_z:
other_z = random.randint(1, 92)
comp2 = Ion(Composition({fixed_el: 1, Element.from_Z(other_z): 0}), 1)
self.assertEqual(comp1, comp2,
"Composition equality test failed. " +
"%s should be equal to %s" % (comp1.formula,
comp2.formula))
self.assertEqual(comp1.__hash__(), comp2.__hash__(),
"Hashcode equality test failed!")
def setUp(self):
comp = Composition("Mn2O3")
self.solentry = PDEntry(comp, 49)
ion = Ion.from_formula("MnO4-")
self.ionentry = IonEntry(ion, 25)
self.PxIon = PourbaixEntry(self.ionentry)
self.PxSol = PourbaixEntry(self.solentry)
self.PxIon.set_conc(1e-4)
def test_as_dict(self):
c = Ion.from_dict({"Mn": 1, "O": 4, "charge": -1})
d = c.as_dict()
correct_dict = {"Mn": 1.0, "O": 4.0, "charge": -1.0}
self.assertEqual(d, correct_dict)
self.assertEqual(d["charge"], correct_dict["charge"])
correct_dict = {"Mn": 1.0, "O": 4.0, "charge": -1}
d = c.to_reduced_dict
self.assertEqual(d, correct_dict)
self.assertEqual(d["charge"], correct_dict["charge"])
def test_as_dict(self):
c = Ion.from_dict({'Mn': 1, 'O': 4, 'charge': -1})
d = c.as_dict()
correct_dict = {'Mn': 1.0, 'O': 4.0, 'charge': -1.0}
self.assertEqual(d, correct_dict)
self.assertEqual(d['charge'], correct_dict['charge'])
correct_dict = {'Mn': 1.0, 'O': 4.0, 'charge': -1}
d = c.to_reduced_dict
self.assertEqual(d, correct_dict)
self.assertEqual(d['charge'], correct_dict['charge'])
def test_as_dict(self):
c = Ion.from_dict({'Mn': 1, 'O': 4, 'charge': -1})
d = c.as_dict()
correct_dict = {'Mn': 1.0, 'O': 4.0, 'charge': -1.0}
self.assertEqual(d, correct_dict)
self.assertEqual(d['charge'], correct_dict['charge'])
correct_dict = {'Mn': 1.0, 'O': 4.0, 'charge': -1}
d = c.to_reduced_dict
self.assertEqual(d, correct_dict)
self.assertEqual(d['charge'], correct_dict['charge'])
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_special_formulas(self):
special_formulas = [
("Cl-", "Cl[-1]"),
("H+", "H[+1]"),
("F-", "F[-1]"),
("H4O4", "H2O2(aq)"),
("OH-", "OH[-1]"),
("CH3COO-", "CH3COO[-1]"),
("CH3COOH", "CH3COOH(aq)"),
("CH3OH", "CH3OH(aq)"),
("H4CO", "CH3OH(aq)"),
("C2H6O", "C2H5OH(aq)"),
("C3H8O", "C3H7OH(aq)"),
("C4H10O", "C4H9OH(aq)"),
("Fe(OH)4+", "FeO2.2H2O[+1]"),
("Zr(OH)4", "ZrO2.2H2O(aq)"),
]
for tup in special_formulas:
self.assertEqual(Ion.from_formula(tup[0]).reduced_formula, tup[1])
self.assertEqual(Ion.from_formula("Fe(OH)4+").get_reduced_formula_and_factor(hydrates=False), ("Fe(OH)4", 1))
self.assertEqual(Ion.from_formula("Zr(OH)4").get_reduced_formula_and_factor(hydrates=False), ("Zr(OH)4", 1))
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 __init__(self, entries, comp_dict=None):
"""
Args:
entries:
Entries list containing both Solids and Ions
comp_dict:
Dictionary of compositions
"""
self._solid_entries = list()
self._ion_entries = list()
for entry in entries:
if entry.phase_type == "Solid":
self._solid_entries.append(entry)
elif entry.phase_type == "Ion":
self._ion_entries.append(entry)
else:
raise StandardError("Incorrect Phase type - needs to be \
Pourbaix entry of phase type Ion/Solid")
self._unprocessed_entries = self._solid_entries + self._ion_entries
self._elt_comp = comp_dict
if comp_dict:
self._multielement = True
self.pourbaix_elements = [key for key in comp_dict]
w = [comp_dict[key] for key in comp_dict]
A = []
for comp in comp_dict:
m = re.search(r"\[([^\[\]]+)\]|\(aq\)", comp)
if m:
comp_obj = Ion.from_formula(comp)
else:
comp_obj = Composition.from_formula(comp)
Ai = []
for elt in self.pourbaix_elements:
Ai.append(comp_obj[Element(elt)])
A.append(Ai)
A = np.array(A).T.astype(float)
w = np.array(w)
A /= np.dot([A[i].sum() for i in xrange(len(A))], w)
x = np.linalg.solve(A, w)
self._elt_comp = dict(zip(self.pourbaix_elements, x))
else:
self._multielement = False
self.pourbaix_elements = [
el.symbol for el in entries[0].composition.elements
if el.symbol not in ["H", "O"]
]
self._make_pourbaixdiagram()
def __init__(self, entries, comp_dict=None):
"""
Args:
entries:
Entries list containing both Solids and Ions
comp_dict:
Dictionary of compositions
"""
self._solid_entries = list()
self._ion_entries = list()
for entry in entries:
if entry.phase_type == "Solid":
self._solid_entries.append(entry)
elif entry.phase_type == "Ion":
self._ion_entries.append(entry)
else:
raise StandardError("Incorrect Phase type - needs to be \
Pourbaix entry of phase type Ion/Solid")
self._unprocessed_entries = self._solid_entries + self._ion_entries
self._elt_comp = comp_dict
if comp_dict:
self._multielement = True
self.pourbaix_elements = [key for key in comp_dict]
w = [comp_dict[key] for key in comp_dict]
A = []
for comp in comp_dict:
m = re.search(r"\[([^\[\]]+)\]|\(aq\)", comp)
if m:
comp_obj = Ion.from_formula(comp)
else:
comp_obj = Composition.from_formula(comp)
Ai = []
for elt in self.pourbaix_elements:
Ai.append(comp_obj[Element(elt)])
A.append(Ai)
A = np.array(A).T.astype(float)
w = np.array(w)
A /= np.dot([A[i].sum() for i in xrange(len(A))], w)
x = np.linalg.solve(A, w)
self._elt_comp = dict(zip(self.pourbaix_elements, x))
else:
self._multielement = False
self.pourbaix_elements = [el.symbol
for el in entries[0].composition.elements
if el.symbol not in ["H", "O"]]
self._make_pourbaixdiagram()
def test_get_decomposition(self):
# Test a stable entry to ensure that it's zero in the stable region
entry = self.test_data["Zn"][12] # Should correspond to mp-2133
self.assertAlmostEqual(
self.pbx.get_decomposition_energy(entry, 10, 1),
0.0,
5,
"Decomposition energy of ZnO is not 0.",
)
# Test an unstable entry to ensure that it's never zero
entry = self.test_data["Zn"][11]
ph, v = np.meshgrid(np.linspace(0, 14), np.linspace(-2, 4))
result = self.pbx_nofilter.get_decomposition_energy(entry, ph, v)
self.assertTrue((result >= 0).all(),
"Unstable energy has hull energy of 0 or less")
# Test an unstable hydride to ensure HER correction works
self.assertAlmostEqual(
self.pbx.get_decomposition_energy(entry, -3, -2), 3.6979147983333)
# Test a list of pHs
self.pbx.get_decomposition_energy(entry, np.linspace(0, 2, 5), 2)
# Test a list of Vs
self.pbx.get_decomposition_energy(entry, 4, np.linspace(-3, 3, 10))
# Test a set of matching arrays
ph, v = np.meshgrid(np.linspace(0, 14), np.linspace(-3, 3))
self.pbx.get_decomposition_energy(entry, ph, v)
# Test custom ions
entries = self.test_data["C-Na-Sn"]
ion = IonEntry(Ion.from_formula("NaO28H80Sn12C24+"), -161.676)
custom_ion_entry = PourbaixEntry(ion, entry_id="my_ion")
pbx = PourbaixDiagram(
entries + [custom_ion_entry],
filter_solids=True,
comp_dict={
"Na": 1,
"Sn": 12,
"C": 24
},
)
self.assertAlmostEqual(
pbx.get_decomposition_energy(custom_ion_entry, 5, 2), 2.1209002582,
1)
def ion_or_solid_comp_object(formula):
"""
Returns either an ion object or composition object given
a formula.
Args:
formula: String formula. Eg. of ion: NaOH(aq), Na[+];
Eg. of solid: Fe2O3(s), Fe(s), Na2O
Returns:
Composition/Ion object
"""
m = re.search(r"\[([^\[\]]+)\]|\(aq\)", formula)
if m:
comp_obj = Ion.from_formula(formula)
elif re.search(r"\(s\)", formula):
comp_obj = Composition(formula[:-3])
else:
comp_obj = Composition(formula)
return comp_obj
def ion_or_solid_comp_object(formula):
"""
Returns either an ion object or composition object given
a formula.
Args:
formula: String formula. Eg. of ion: NaOH(aq), Na[+];
Eg. of solid: Fe2O3(s), Fe(s), Na2O
Returns:
Composition/Ion object
"""
m = re.search(r"\[([^\[\]]+)\]|\(aq\)", formula)
if m:
comp_obj = Ion.from_formula(formula)
elif re.search(r"\(s\)", formula):
comp_obj = Composition(formula[:-3])
else:
comp_obj = Composition(formula)
return comp_obj
def from_csv(filename):
"""
Imports PourbaixEntries from a csv.
Args:
filename - Filename to import from.
Returns:
List of Entries
"""
import csv
reader = csv.reader(open(filename, "rb"),
delimiter=",",
quotechar="\"",
quoting=csv.QUOTE_MINIMAL)
entries = list()
header_read = False
for row in reader:
if not header_read:
elements = row[1:(len(row) - 4)]
header_read = True
else:
name = row[0]
energy = float(row[-4])
conc = float(row[-1])
comp = dict()
for ind in range(1, len(row) - 4):
if float(row[ind]) > 0:
comp[Element(elements[ind - 1])] = float(row[ind])
phase_type = row[-3]
if phase_type == "Ion":
PoE = PourbaixEntry(
IonEntry(Ion.from_formula(name), energy))
PoE.set_conc(conc)
PoE.set_name(name)
entries.append(PoE)
else:
entries.append(
PourbaixEntry(PDEntry(Composition(comp), energy)))
elements = [Element(el) for el in elements]
return elements, entries
def test_equals(self):
random_z = random.randint(1, 92)
fixed_el = Element.from_Z(random_z)
other_z = random.randint(1, 92)
while other_z == random_z:
other_z = random.randint(1, 92)
comp1 = Ion(Composition({fixed_el: 1, Element.from_Z(other_z): 0}), 1)
other_z = random.randint(1, 92)
while other_z == random_z:
other_z = random.randint(1, 92)
comp2 = Ion(Composition({fixed_el: 1, Element.from_Z(other_z): 0}), 1)
self.assertEqual(
comp1, comp2, "Composition equality test failed. " +
"%s should be equal to %s" % (comp1.formula, comp2.formula))
self.assertEqual(comp1.__hash__(), comp2.__hash__(),
"Hashcode equality test failed!")
def from_csv(filename):
"""
Imports PourbaixEntries from a csv.
Args:
filename: Filename to import from.
Returns:
List of Entries
"""
with open(filename, "r") as f:
reader = csv.reader(f, delimiter=unicode2str(","),
quotechar=unicode2str("\""),
quoting=csv.QUOTE_MINIMAL)
entries = list()
header_read = False
for row in reader:
if not header_read:
elements = row[1:(len(row) - 4)]
header_read = True
else:
name = row[0]
energy = float(row[-4])
conc = float(row[-1])
comp = dict()
for ind in range(1, len(row) - 4):
if float(row[ind]) > 0:
comp[Element(elements[ind - 1])] = float(row[ind])
phase_type = row[-3]
if phase_type == "Ion":
PoE = PourbaixEntry(IonEntry(Ion.from_formula(name),
energy))
PoE.conc = conc
PoE.name = name
entries.append(PoE)
else:
entries.append(PourbaixEntry(PDEntry(Composition(comp),
energy)))
elements = [Element(el) for el in elements]
return elements, entries
def mke_pour_ion_entr(mtnme, ion_dict, stable_solids_minus_h2o, ref_state, entries_aqcorr, ref_dict):
"""
"""
#| - mke_pour_ion_entr
from pymatgen import Element # Accesses properties of element
from pymatgen.core.ion import Ion
from pymatgen.phasediagram.maker import PhaseDiagram
from pymatgen.analysis.pourbaix.entry import PourbaixEntry, IonEntry
from pd_make import ref_entry_find, ref_entry_stoich
pd = PhaseDiagram(entries_aqcorr)
ref_entry = ref_entry_find(stable_solids_minus_h2o, ref_state)
ref_stoich_fact = ref_entry_stoich(ref_entry)
## Calculate DFT reference E for ions (Persson et al, PRB (2012))
dft_for_e=pd.get_form_energy(ref_entry)/ref_stoich_fact # DFT formation E, normalized by composition "factor"
ion_correction_1 = dft_for_e-ref_dict[ref_state] # Difference of DFT form E and exp for E of reference
el = Element(mtnme)
pbx_ion_entries_1 = []
for id in ion_dict:
comp = Ion.from_formula(id['Name']) # Ion name-> Ion comp name (ex. Fe[3+] -> Ion: Fe1 +3)
# comp.composition[el] : number of Fe atoms in ion
num_el_ref = (ref_entry.composition[el]) / ref_stoich_fact # number of element atoms in reference
factor = comp.composition[el] / num_el_ref # Stoicheometric factor for ionic correction
# (i.e. Fe2O3 ref but calc E for Fe[2+] ion)
energy = id['Energy'] + ion_correction_1 * factor
#TEMP_PRINT
if id['Name']=='Pd[2+]':
energy = 123
# print id['Name']
pbx_entry_ion = PourbaixEntry(IonEntry(comp, energy))
pbx_entry_ion.name = id['Name']
pbx_ion_entries_1.append(pbx_entry_ion)
return pbx_ion_entries_1
def test_mpr_pipeline(self):
from pymatgen import MPRester
mpr = MPRester()
data = mpr.get_pourbaix_entries(["Zn"])
pbx = PourbaixDiagram(data, filter_solids=True, conc_dict={"Zn": 1e-8})
pbx.find_stable_entry(10, 0)
data = mpr.get_pourbaix_entries(["Ag", "Te"])
pbx = PourbaixDiagram(data, filter_solids=True,
conc_dict={"Ag": 1e-8, "Te": 1e-8})
self.assertEqual(len(pbx.stable_entries), 30)
test_entry = pbx.find_stable_entry(8, 2)
self.assertAlmostEqual(test_entry.energy, 2.393900378500001)
# Test custom ions
entries = mpr.get_pourbaix_entries(["Sn", "C", "Na"])
ion = IonEntry(Ion.from_formula("NaO28H80Sn12C24+"), -161.676)
custom_ion_entry = PourbaixEntry(ion, entry_id='my_ion')
pbx = PourbaixDiagram(entries + [custom_ion_entry], filter_solids=True,
comp_dict={"Na": 1, "Sn": 12, "C": 24})
self.assertAlmostEqual(pbx.get_decomposition_energy(custom_ion_entry, 5, 2),
8.31082110278154)
def get_pourbaix_plot_colorfill_by_element(self, limits=None, title="",
label_domains=True, element=None):
"""
Color domains by element
"""
from matplotlib.patches import Polygon
entry_dict_of_multientries = collections.defaultdict(list)
plt = pretty_plot(16)
optim_colors = ['#0000FF', '#FF0000', '#00FF00', '#FFFF00', '#FF00FF',
'#FF8080', '#DCDCDC', '#800000', '#FF8000']
optim_font_color = ['#FFFFA0', '#00FFFF', '#FF00FF', '#0000FF', '#00FF00',
'#007F7F', '#232323', '#7FFFFF', '#007FFF']
hatch = ['/', '\\', '|', '-', '+', 'o', '*']
(stable, unstable) = self.pourbaix_plot_data(limits)
num_of_overlaps = {key: 0 for key in stable.keys()}
for entry in stable:
if isinstance(entry, MultiEntry):
for e in entry.entrylist:
if element in e.composition.elements:
entry_dict_of_multientries[e.name].append(entry)
num_of_overlaps[entry] += 1
else:
entry_dict_of_multientries[entry.name].append(entry)
if limits:
xlim = limits[0]
ylim = limits[1]
else:
xlim = self._analyzer.chempot_limits[0]
ylim = self._analyzer.chempot_limits[1]
h_line = np.transpose([[xlim[0], -xlim[0] * PREFAC],
[xlim[1], -xlim[1] * PREFAC]])
o_line = np.transpose([[xlim[0], -xlim[0] * PREFAC + 1.23],
[xlim[1], -xlim[1] * PREFAC + 1.23]])
neutral_line = np.transpose([[7, ylim[0]], [7, ylim[1]]])
V0_line = np.transpose([[xlim[0], 0], [xlim[1], 0]])
ax = plt.gca()
ax.set_xlim(xlim)
ax.set_ylim(ylim)
from pymatgen import Composition, Element
from pymatgen.core.ion import Ion
def len_elts(entry):
if "(s)" in entry:
comp = Composition(entry[:-3])
else:
comp = Ion.from_formula(entry)
return len([el for el in comp.elements if el not in
[Element("H"), Element("O")]])
sorted_entry = entry_dict_of_multientries.keys()
sorted_entry.sort(key=len_elts)
i = -1
label_chr = map(chr, list(range(65, 91)))
for entry in sorted_entry:
color_indx = 0
x_coord = 0.0
y_coord = 0.0
npts = 0
i += 1
for e in entry_dict_of_multientries[entry]:
hc = 0
fc = 0
bc = 0
xy = self.domain_vertices(e)
c = self.get_center(stable[e])
x_coord += c[0]
y_coord += c[1]
npts += 1
color_indx = i
if "(s)" in entry:
comp = Composition(entry[:-3])
else:
comp = Ion.from_formula(entry)
if len([el for el in comp.elements if el not in
[Element("H"), Element("O")]]) == 1:
if color_indx >= len(optim_colors):
color_indx = color_indx -\
int(color_indx / len(optim_colors)) * len(optim_colors)
patch = Polygon(xy, facecolor=optim_colors[color_indx],
closed=True, lw=3.0, fill=True)
bc = optim_colors[color_indx]
else:
if color_indx >= len(hatch):
color_indx = color_indx - int(color_indx / len(hatch)) * len(hatch)
patch = Polygon(xy, hatch=hatch[color_indx], closed=True, lw=3.0, fill=False)
hc = hatch[color_indx]
ax.add_patch(patch)
xy_center = (x_coord / npts, y_coord / npts)
if label_domains:
if color_indx >= len(optim_colors):
color_indx = color_indx -\
int(color_indx / len(optim_colors)) * len(optim_colors)
fc = optim_font_color[color_indx]
if bc and not hc:
bbox = dict(boxstyle="round", fc=fc)
if hc and not bc:
bc = 'k'
fc = 'w'
bbox = dict(boxstyle="round", hatch=hc, fill=False)
if bc and hc:
bbox = dict(boxstyle="round", hatch=hc, fc=fc)
# bbox.set_path_effects([PathEffects.withSimplePatchShadow()])
plt.annotate(latexify_ion(latexify(entry)), xy_center,
color=bc, fontsize=30, bbox=bbox)
# plt.annotate(label_chr[i], xy_center,
# color=bc, fontsize=30, bbox=bbox)
lw = 3
plt.plot(h_line[0], h_line[1], "r--", linewidth=lw)
plt.plot(o_line[0], o_line[1], "r--", linewidth=lw)
plt.plot(neutral_line[0], neutral_line[1], "k-.", linewidth=lw)
plt.plot(V0_line[0], V0_line[1], "k-.", linewidth=lw)
plt.xlabel("pH")
plt.ylabel("E (V)")
plt.title(title, fontsize=20, fontweight='bold')
return plt
def from_dict(cls, d):
"""
Returns an IonEntry object from a dict.
"""
return IonEntry(Ion.from_dict(d["composition"]), d["energy"])
pbx_solid_entries = []
for entry in stable_solids_minus_h2o:
pbx_entry = PourbaixEntry(entry)
# Replace E with newly corrected E
pbx_entry.g0_replace(pd.get_form_energy(entry))
pbx_entry.reduced_entry() # Applies reduction factor?????
pbx_solid_entries.append(pbx_entry)
# | - Processing My Solid Entries
for key, value in ion_dict_solids_expt.items():
print("IDJFIJDS")
split_key = key.split("_")
formula_i = split_key[0]
comp = Ion.from_formula(formula_i)
energy = value
pbx_entry_ion = PourbaixEntry(
ComputedEntry(comp, energy, attribute={"full_name": key}))
# AP pbx_entry_ion.name = key
pbx_entry_ion.conc = 1
pbx_solid_entries.append(pbx_entry_ion)
for a in pbx_solid_entries:
print(a, a.conc)
print('hkjo')
#__|
# +
def test_get_composition(self):
comp = self.entry.composition
expected_comp = Ion.from_formula('MnO4[-]')
self.assertEqual(comp, expected_comp, "Wrong composition!")
def from_dict(cls, d):
"""
Returns an IonEntry object from a dict.
"""
return IonEntry(Ion.from_dict(d["ion"]), d["energy"], d.get("name", None))
def test_mixed_valence(self):
comp = Ion(Composition({"Fe2+": 2, "Fe3+": 4, "Li+": 8}))
self.assertEqual(comp.reduced_formula, "Li4Fe3(aq)")
self.assertEqual(comp.alphabetical_formula, "Fe6 Li8")
self.assertEqual(comp.formula, "Li8 Fe6")
def plot_pourbaix_diagram(metastability=0.0,
ion_concentration=1e-6,
fmt='pdf'):
"""
Creates a Pourbaix diagram for the material in the cwd.
Args:
metastability (float): desired metastable tolerance energy
(meV/atom). <~50 is generally a sensible range to use.
ion_concentration (float): in mol/kg. Sensible values are
generally between 1e-8 and 1.
fmt (str): matplotlib format style. Check the matplotlib
docs for options.
"""
# Create a ComputedEntry object for the 2D material.
composition = Structure.from_file('POSCAR').composition
energy = Vasprun('vasprun.xml').final_energy
cmpd = ComputedEntry(composition, energy)
# Define the chemsys that describes the 2D compound.
chemsys = ['O', 'H'] + [
elt.symbol
for elt in composition.elements if elt.symbol not in ['O', 'H']
]
# Pick out the ions pertaining to the 2D compound.
ion_dict = dict()
for elt in chemsys:
if elt not in ['O', 'H'] and ION_FORMATION_ENERGIES[elt]:
ion_dict.update(ION_FORMATION_ENERGIES[elt])
elements = [Element(elt) for elt in chemsys if elt not in ['O', 'H']]
# Add "correction" for metastability
cmpd.correction -= float(cmpd.composition.num_atoms)\
* float(metastability) / 1000.0
# Calculate formation energy of the compound from its end
# members
form_energy = cmpd.energy
for elt in composition.as_dict():
form_energy -= CHEMICAL_POTENTIALS[elt] * cmpd.composition[elt]
# Convert the compound entry to a pourbaix entry.
# Default concentration for solid entries = 1
pbx_cmpd = PourbaixEntry(cmpd)
pbx_cmpd.g0_replace(form_energy)
pbx_cmpd.reduced_entry()
# Add corrected ionic entries to the pourbaix diagram
# dft corrections for experimental ionic energies:
# Persson et.al PHYSICAL REVIEW B 85, 235438 (2012)
pbx_ion_entries = list()
# Get PourbaixEntry corresponding to each ion.
# Default concentration for ionic entries = 1e-6
# ion_energy = ion_exp_energy + ion_correction * factor
# where factor = fraction of element el in the ionic entry
# compared to the reference entry
for elt in elements:
for key in ion_dict:
comp = Ion.from_formula(key)
if comp.composition[elt] != 0:
factor = comp.composition[elt]
energy = ion_dict[key]
pbx_entry_ion = PourbaixEntry(IonEntry(comp, energy))
pbx_entry_ion.correction = (ION_CORRECTIONS[elt.symbol] *
factor)
pbx_entry_ion.conc = ion_concentration
pbx_entry_ion.name = key
pbx_ion_entries.append(pbx_entry_ion)
# Generate and plot Pourbaix diagram
# Each bulk solid/ion has a free energy g of the form:
# g = g0_ref + 0.0591 * log10(conc) - nO * mu_H2O +
# (nH - 2nO) * pH + phi * (-nH + 2nO + q)
all_entries = [pbx_cmpd] + pbx_ion_entries
pourbaix = PourbaixDiagram(all_entries)
# Analysis features
# panalyzer = PourbaixAnalyzer(pourbaix)
# instability = panalyzer.get_e_above_hull(pbx_cmpd)
plotter = PourbaixPlotter(pourbaix)
plot = plotter.get_pourbaix_plot(limits=[[0, 14], [-2, 2]],
label_domains=True)
fig = plot.gcf()
ax1 = fig.gca()
# Add coloring to highlight the stability region for the 2D
# material, if one exists.
stable_entries = plotter.pourbaix_plot_data(limits=[[0, 14], [-2, 2]])[0]
for entry in stable_entries:
if entry == pbx_cmpd:
col = plt.cm.Blues(0)
else:
col = plt.cm.rainbow(
float(ION_COLORS[entry.composition.reduced_formula]))
vertices = plotter.domain_vertices(entry)
patch = Polygon(vertices, closed=True, fill=True, color=col)
ax1.add_patch(patch)
fig.set_size_inches((11.5, 9))
plot.tight_layout(pad=1.09)
# Save plot
if metastability:
plot.suptitle('Metastable Tolerance ='
' {} meV/atom'.format(metastability),
fontsize=20)
plot.savefig('{}_{}.{}'.format(composition.reduced_formula,
ion_concentration, fmt),
transparent=True)
else:
plot.savefig('{}_{}.{}'.format(composition.reduced_formula,
ion_concentration, fmt),
transparent=True)
plot.close()
def len_elts(entry):
comp = Composition(entry[:-3]) if "(s)" in entry else Ion.from_formula(entry)
return len(set(comp.elements) - {Element("H"), Element("O")})
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 test_from_dict(self):
sym_dict = {"P": 1, "O": 4, 'charge': -2}
self.assertEqual(Ion.from_dict(sym_dict).reduced_formula,
"PO4[2-]",
"Creation form sym_amount dictionary failed!")
def setUp(self):
ion = Ion.from_formula("MnO4[-]")
self.entry = IonEntry(ion, 49)
def get_pourbaix_plot_colorfill_by_element(self, limits=None, title="",
label_domains=True, element=None):
"""
Color domains by element
"""
from matplotlib.patches import Polygon
import matplotlib.patheffects as PathEffects
entry_dict_of_multientries = collections.defaultdict(list)
plt = get_publication_quality_plot(16)
optim_colors = ['#0000FF', '#FF0000', '#00FF00', '#FFFF00', '#FF00FF',
'#FF8080', '#DCDCDC', '#800000', '#FF8000']
optim_font_color = ['#FFFFA0', '#00FFFF', '#FF00FF', '#0000FF', '#00FF00',
'#007F7F', '#232323', '#7FFFFF', '#007FFF']
hatch = ['/', '\\', '|', '-', '+', 'o', '*']
(stable, unstable) = self.pourbaix_plot_data(limits)
num_of_overlaps = {key: 0 for key in stable.keys()}
for entry in stable:
if isinstance(entry, MultiEntry):
for e in entry.entrylist:
if element in e.composition.elements:
entry_dict_of_multientries[e.name].append(entry)
num_of_overlaps[entry] += 1
else:
entry_dict_of_multientries[entry.name].append(entry)
if limits:
xlim = limits[0]
ylim = limits[1]
else:
xlim = self._analyzer.chempot_limits[0]
ylim = self._analyzer.chempot_limits[1]
h_line = np.transpose([[xlim[0], -xlim[0] * PREFAC],
[xlim[1], -xlim[1] * PREFAC]])
o_line = np.transpose([[xlim[0], -xlim[0] * PREFAC + 1.23],
[xlim[1], -xlim[1] * PREFAC + 1.23]])
neutral_line = np.transpose([[7, ylim[0]], [7, ylim[1]]])
V0_line = np.transpose([[xlim[0], 0], [xlim[1], 0]])
ax = plt.gca()
ax.set_xlim(xlim)
ax.set_ylim(ylim)
from pymatgen import Composition, Element
from pymatgen.core.ion import Ion
def len_elts(entry):
if "(s)" in entry:
comp = Composition(entry[:-3])
else:
comp = Ion.from_formula(entry)
return len([el for el in comp.elements if el not in
[Element("H"), Element("O")]])
sorted_entry = entry_dict_of_multientries.keys()
sorted_entry.sort(key=len_elts)
i = -1
label_chr = map(chr, range(65, 91))
for entry in sorted_entry:
color_indx = 0
x_coord = 0.0
y_coord = 0.0
npts = 0
i += 1
for e in entry_dict_of_multientries[entry]:
hc = 0
fc = 0
bc = 0
xy = self.domain_vertices(e)
c = self.get_center(stable[e])
x_coord += c[0]
y_coord += c[1]
npts += 1
color_indx = i
if "(s)" in entry:
comp = Composition(entry[:-3])
else:
comp = Ion.from_formula(entry)
if len([el for el in comp.elements if el not in
[Element("H"), Element("O")]]) == 1:
if color_indx >= len(optim_colors):
color_indx = color_indx -\
int(color_indx / len(optim_colors)) * len(optim_colors)
patch = Polygon(xy, facecolor=optim_colors[color_indx],
closed=True, lw=3.0, fill=True)
bc = optim_colors[color_indx]
else:
if color_indx >= len(hatch):
color_indx = color_indx - int(color_indx / len(hatch)) * len(hatch)
patch = Polygon(xy, hatch=hatch[color_indx], closed=True, lw=3.0, fill=False)
hc = hatch[color_indx]
ax.add_patch(patch)
xy_center = (x_coord / npts, y_coord / npts)
if label_domains:
if color_indx >= len(optim_colors):
color_indx = color_indx -\
int(color_indx / len(optim_colors)) * len(optim_colors)
fc = optim_font_color[color_indx]
if bc and not hc:
bbox = dict(boxstyle="round", fc=fc)
if hc and not bc:
bc = 'k'
fc = 'w'
bbox = dict(boxstyle="round", hatch=hc, fill=False)
if bc and hc:
bbox = dict(boxstyle="round", hatch=hc, fc=fc)
# bbox.set_path_effects([PathEffects.withSimplePatchShadow()])
# plt.annotate(latexify_ion(latexify(entry)), xy_center,
# color=fc, fontsize=30, bbox=bbox)
plt.annotate(label_chr[i], xy_center,
color=bc, fontsize=30, bbox=bbox)
lw = 3
plt.plot(h_line[0], h_line[1], "r--", linewidth=lw)
plt.plot(o_line[0], o_line[1], "r--", linewidth=lw)
plt.plot(neutral_line[0], neutral_line[1], "k-.", linewidth=lw)
plt.plot(V0_line[0], V0_line[1], "k-.", linewidth=lw)
plt.xlabel("pH")
plt.ylabel("E (V)")
plt.title(title, fontsize=20, fontweight='bold')
return plt
def test_get_composition(self):
comp = self.entry.composition
expected_comp = Ion.from_formula('MnO4[-]')
self.assertEquals(comp, expected_comp, "Wrong composition!")
def setUp(self):
ion = Ion.from_formula("MnO4[-]")
self.entry = IonEntry(ion, 49)
def len_elts(entry):
comp = Composition(
entry[:-3]) if "(s)" in entry else Ion.from_formula(entry)
return len(set(comp.elements) - {Element("H"), Element("O")})
def plot_pourbaix_diagram(metastability=0.0, ion_concentration=1e-6, fmt='pdf'):
"""
Creates a Pourbaix diagram for the material in the cwd.
Args:
metastability (float): desired metastable tolerance energy
(meV/atom). <~50 is generally a sensible range to use.
ion_concentration (float): in mol/kg. Sensible values are
generally between 1e-8 and 1.
fmt (str): matplotlib format style. Check the matplotlib
docs for options.
"""
# Create a ComputedEntry object for the 2D material.
composition = Structure.from_file('POSCAR').composition
energy = Vasprun('vasprun.xml').final_energy
cmpd = ComputedEntry(composition, energy)
# Define the chemsys that describes the 2D compound.
chemsys = ['O', 'H'] + [elt.symbol for elt in composition.elements
if elt.symbol not in ['O', 'H']]
# Experimental ionic energies
# See ions.yaml for ion formation energies and references.
exp_dict = ION_DATA['ExpFormEnergy']
ion_correction = ION_DATA['IonCorrection']
# Pick out the ions pertaining to the 2D compound.
ion_dict = dict()
for elt in chemsys:
if elt not in ['O', 'H'] and exp_dict[elt]:
ion_dict.update(exp_dict[elt])
elements = [Element(elt) for elt in chemsys if elt not in ['O', 'H']]
# Add "correction" for metastability
cmpd.correction -= float(cmpd.composition.num_atoms)\
* float(metastability) / 1000.0
# Calculate formation energy of the compound from its end
# members
form_energy = cmpd.energy
for elt in composition.as_dict():
form_energy -= END_MEMBERS[elt] * cmpd.composition[elt]
# Convert the compound entry to a pourbaix entry.
# Default concentration for solid entries = 1
pbx_cmpd = PourbaixEntry(cmpd)
pbx_cmpd.g0_replace(form_energy)
pbx_cmpd.reduced_entry()
# Add corrected ionic entries to the pourbaix diagram
# dft corrections for experimental ionic energies:
# Persson et.al PHYSICAL REVIEW B 85, 235438 (2012)
pbx_ion_entries = list()
# Get PourbaixEntry corresponding to each ion.
# Default concentration for ionic entries = 1e-6
# ion_energy = ion_exp_energy + ion_correction * factor
# where factor = fraction of element el in the ionic entry
# compared to the reference entry
for elt in elements:
for key in ion_dict:
comp = Ion.from_formula(key)
if comp.composition[elt] != 0:
factor = comp.composition[elt]
energy = ion_dict[key]
pbx_entry_ion = PourbaixEntry(IonEntry(comp, energy))
pbx_entry_ion.correction = ion_correction[elt.symbol]\
* factor
pbx_entry_ion.conc = ion_concentration
pbx_entry_ion.name = key
pbx_ion_entries.append(pbx_entry_ion)
# Generate and plot Pourbaix diagram
# Each bulk solid/ion has a free energy g of the form:
# g = g0_ref + 0.0591 * log10(conc) - nO * mu_H2O +
# (nH - 2nO) * pH + phi * (-nH + 2nO + q)
all_entries = [pbx_cmpd] + pbx_ion_entries
pourbaix = PourbaixDiagram(all_entries)
# Analysis features
panalyzer = PourbaixAnalyzer(pourbaix)
# instability = panalyzer.get_e_above_hull(pbx_cmpd)
plotter = PourbaixPlotter(pourbaix)
plot = plotter.get_pourbaix_plot(limits=[[0, 14], [-2, 2]],
label_domains=True)
fig = plot.gcf()
ax1 = fig.gca()
# Add coloring to highlight the stability region for the 2D
# material, if one exists.
stable_entries = plotter.pourbaix_plot_data(
limits=[[0, 14], [-2, 2]])[0]
for entry in stable_entries:
if entry == pbx_cmpd:
col = plt.cm.Blues(0)
else:
col = plt.cm.rainbow(float(
ION_COLORS[entry.composition.reduced_formula]))
vertices = plotter.domain_vertices(entry)
patch = Polygon(vertices, closed=True, fill=True, color=col)
ax1.add_patch(patch)
fig.set_size_inches((11.5, 9))
plot.tight_layout(pad=1.09)
# Save plot
if metastability:
plot.suptitle('Metastable Tolerance ='
' {} meV/atom'.format(metastability),
fontsize=20)
plot.savefig('{}_{}.{}'.format(
composition.reduced_formula, ion_concentration, fmt),
transparent=True)
else:
plot.savefig('{}_{}.{}'.format(composition.reduced_formula,
ion_concentration, fmt),
transparent=True)
plot.close()
def plot_pourbaix_diagram(metastability=0.0, ion_concentration=1e-6, fmt='pdf'):
"""
Creates a Pourbaix diagram for the material in the cwd.
Args:
metastability (float): desired metastable tolerance energy
(meV/atom). <~50 is generally a sensible range to use.
ion_concentration (float): in mol/kg. Sensible values are
generally between 1e-8 and 1.
fmt (str): matplotlib format style. Check the matplotlib
docs for options.
"""
# Create a ComputedEntry object for the 2D material.
composition = Structure.from_file('POSCAR').composition
energy = Vasprun('vasprun.xml').final_energy
cmpd = ComputedEntry(composition, energy)
# Define the chemsys that describes the 2D compound.
chemsys = ['O', 'H'] + [elt.symbol for elt in composition.elements
if elt.symbol not in ['O', 'H']]
# Pick out the ions pertaining to the 2D compound.
ion_dict = dict()
for elt in chemsys:
if elt not in ['O', 'H'] and ION_FORMATION_ENERGIES[elt]:
ion_dict.update(ION_FORMATION_ENERGIES[elt])
elements = [Element(elt) for elt in chemsys if elt not in ['O', 'H']]
# Add "correction" for metastability
cmpd.correction -= float(cmpd.composition.num_atoms)\
* float(metastability) / 1000.0
# Calculate formation energy of the compound from its end
# members
form_energy = cmpd.energy
for elt in composition.as_dict():
form_energy -= CHEMICAL_POTENTIALS[elt] * cmpd.composition[elt]
# Convert the compound entry to a pourbaix entry.
# Default concentration for solid entries = 1
pbx_cmpd = PourbaixEntry(cmpd)
pbx_cmpd.g0_replace(form_energy)
pbx_cmpd.reduced_entry()
# Add corrected ionic entries to the pourbaix diagram
# dft corrections for experimental ionic energies:
# Persson et.al PHYSICAL REVIEW B 85, 235438 (2012)
pbx_ion_entries = list()
# Get PourbaixEntry corresponding to each ion.
# Default concentration for ionic entries = 1e-6
# ion_energy = ion_exp_energy + ion_correction * factor
# where factor = fraction of element el in the ionic entry
# compared to the reference entry
for elt in elements:
for key in ion_dict:
comp = Ion.from_formula(key)
if comp.composition[elt] != 0:
factor = comp.composition[elt]
energy = ion_dict[key]
pbx_entry_ion = PourbaixEntry(IonEntry(comp, energy))
pbx_entry_ion.correction = (
ION_CORRECTIONS[elt.symbol] * factor
)
pbx_entry_ion.conc = ion_concentration
pbx_entry_ion.name = key
pbx_ion_entries.append(pbx_entry_ion)
# Generate and plot Pourbaix diagram
# Each bulk solid/ion has a free energy g of the form:
# g = g0_ref + 0.0591 * log10(conc) - nO * mu_H2O +
# (nH - 2nO) * pH + phi * (-nH + 2nO + q)
all_entries = [pbx_cmpd] + pbx_ion_entries
total = sum([composition[el] for el in elements])
comp_dict = {el.symbol: composition[el]/total for el in elements}
pourbaix_diagram = PourbaixDiagram(all_entries, comp_dict=comp_dict)
plotter = PourbaixPlotter(pourbaix_diagram)
# Plotting details...
font = "serif"
fig = plt.figure(figsize=(14, 9))
ax1 = fig.gca()
ax1.set_xlim([0, 14])
ax1.set_xticklabels([int(t) for t in ax1.get_xticks()], fontname=font,
fontsize=18)
ax1.set_ylim(-2, 2)
ax1.set_yticklabels(ax1.get_yticks(), fontname=font, fontsize=18)
ax1.set_xlabel("pH", fontname=font, fontsize=18)
ax1.set_ylabel("Potential vs. SHE (V)", fontname=font, fontsize=18)
# Outline water's stability range.
ax1.plot([0, 14], [0, -0.829], color="gray", linestyle="--", alpha=0.7,
linewidth=2)
ax1.plot([0, 14], [1.229, 0.401], color="gray", linestyle="--", alpha=0.7,
linewidth=2)
stable_entries = plotter.pourbaix_plot_data(
limits=[[0, 14], [-2, 2]])[0]
# Add coloring.
colors = sb.color_palette("Set2", len(stable_entries))
i = 0
for entry in stable_entries:
col = colors[i]
i += 1
vertices = plotter.domain_vertices(entry)
center_x = sum([v[0] for v in vertices])/len(vertices)
center_y = sum([v[1] for v in vertices])/len(vertices)
patch = Polygon(vertices, closed=True, fill=True, facecolor=col,
linewidth=2, edgecolor="w")
ax1.text(center_x, center_y, plotter.print_name(entry),
verticalalignment="center", horizontalalignment="center",
fontname=font, fontsize=18)
ax1.add_patch(patch)
plt.savefig("pourbaix.{}".format(fmt))
plt.close()