def supercell(S, mno):
"""Perform supercell expansion for a structure.
New lattice parameters are multiplied and fractional coordinates
divided by corresponding multiplier. New atoms are grouped with
their source in the original cell.
S -- an instance of Structure from diffpy.Structure.
mno -- sequence of 3 integers for cell multipliers along
the a, b and c axes.
Return a new expanded structure instance.
Raise TypeError when S is not Structure instance.
Raise ValueError for invalid mno argument.
"""
# check arguments
if len(mno) != 3:
emsg = "Argument mno must contain 3 numbers."
raise ValueError, emsg
elif min(mno) < 1:
emsg = "Multipliers must be greater or equal 1"
raise ValueError, emsg
if not isinstance(S, Structure):
emsg = "The first argument must be a Structure instance."
raise TypeError, emsg
# convert mno to a tuple of integers so it can be used as range limit.
mno = (int(mno[0]), int(mno[1]), int(mno[2]))
# create return instance
newS = Structure(S)
if mno == (1, 1, 1):
return newS
# back to business
ijklist = [(i,j,k)
for i in range(mno[0])
for j in range(mno[1])
for k in range(mno[2])]
# numpy.floor returns float array
mnofloats = numpy.array(mno, dtype=float)
# build a list of new atoms
newAtoms = []
for a in S:
for ijk in ijklist:
adup = Atom(a)
adup.xyz = (a.xyz + ijk)/mnofloats
newAtoms.append(adup)
# newS can own references in newAtoms, no need to make copies
newS.__setslice__(0, len(newS), newAtoms, copy=False)
# take care of lattice parameters
newS.lattice.setLatPar(
a=mno[0]*S.lattice.a,
b=mno[1]*S.lattice.b,
c=mno[2]*S.lattice.c )
return newS
def test_writeStr_xyz(self):
"""check string representation of normal xyz file"""
stru = self.stru
stru.title = "test of writeStr"
stru.lattice = Lattice(1.0, 2.0, 3.0, 90.0, 90.0, 90.0)
stru[:] = [Atom('H', [1., 1., 1.]), Atom('Cl', [3., 2., 1.])]
s1 = stru.writeStr(self.format)
s1 = re.sub('[ \t]+', ' ', s1)
s0 = "2\n%s\nH 1 2 3\nCl 3 4 3\n" % stru.title
self.assertEqual(s1, s0)
def supercell(S, mno):
"""Perform supercell expansion for a structure.
New lattice parameters are multiplied and fractional coordinates
divided by corresponding multiplier. New atoms are grouped with
their source in the original cell.
S -- an instance of Structure from diffpy.Structure.
mno -- sequence of 3 integers for cell multipliers along
the a, b and c axes.
Return a new expanded structure instance.
Raise TypeError when S is not Structure instance.
Raise ValueError for invalid mno argument.
"""
# check arguments
if len(mno) != 3:
emsg = "Argument mno must contain 3 numbers."
raise ValueError, emsg
elif min(mno) < 1:
emsg = "Multipliers must be greater or equal 1"
raise ValueError, emsg
if not isinstance(S, Structure):
emsg = "The first argument must be a Structure instance."
raise TypeError, emsg
# convert mno to a tuple of integers so it can be used as range limit.
mno = (int(mno[0]), int(mno[1]), int(mno[2]))
# create return instance
newS = Structure(S)
if mno == (1, 1, 1):
return newS
# back to business
ijklist = [(i, j, k) for i in range(mno[0]) for j in range(mno[1])
for k in range(mno[2])]
# numpy.floor returns float array
mnofloats = numpy.array(mno, dtype=float)
# build a list of new atoms
newAtoms = []
for a in S:
for ijk in ijklist:
adup = Atom(a)
adup.xyz = (a.xyz + ijk) / mnofloats
newAtoms.append(adup)
# newS can own references in newAtoms, no need to make copies
newS.__setslice__(0, len(newS), newAtoms, copy=False)
# take care of lattice parameters
newS.lattice.setLatPar(a=mno[0] * S.lattice.a,
b=mno[1] * S.lattice.b,
c=mno[2] * S.lattice.c)
return newS
def test_write_xyz(self):
"""check writing of normal xyz file"""
stru = self.stru
stru.title = "test of writeStr"
stru.lattice = Lattice(1.0, 2.0, 3.0, 90.0, 90.0, 90.0)
stru[:] = [Atom('H', [1., 1., 1.]), Atom('Cl', [3., 2., 1.])]
stru.write(self.tmpname, self.format)
f_s = open(self.tmpname).read()
f_s = re.sub('[ \t]+', ' ', f_s)
s_s = "2\n%s\nH 1 2 3\nCl 3 4 3\n" % stru.title
self.assertEqual(f_s, s_s)
def fccAl():
atoms = [
Atom('Al', (0, 0, 0)),
Atom('Al', (0.5, 0.5, 0)),
Atom('Al', (0.5, 0, 0.5)),
Atom('Al', (0, 0.5, 0.5))
]
a = 4.046
alpha = 90.
lattice = Lattice(a=a, b=a, c=a, alpha=alpha, beta=alpha, gamma=alpha)
return Structure(atoms, lattice, sgid=225)
def fccNi():
atoms = [
Atom('Ni', (0, 0, 0)),
Atom('Ni', (0.5, 0.5, 0)),
Atom('Ni', (0.5, 0, 0.5)),
Atom('Ni', (0, 0.5, 0.5))
]
a = 3.5238
alpha = 90.
lattice = Lattice(a=a, b=a, c=a, alpha=alpha, beta=alpha, gamma=alpha)
return Structure(atoms, lattice, sgid=225)
def setUp(self):
self.stru = Structure( [ Atom('C', [0,0,0]), Atom('C', [1,1,1]) ],
lattice=Lattice(1, 1, 1, 90, 90, 120) )
if not self._loaded_structures:
self._loaded_structures.update([
('cdse', Structure(filename=cdsefile)),
('tei', Structure(filename=teifile)),
('pbte', Structure(filename=pbtefile)),
])
self.__dict__.update(self._loaded_structures)
self.places = 12
return
def expandAsymmetricUnit(self, spacegroup, indices, sgoffset=[0, 0, 0]):
"""Perform symmetry expansion for atoms at given indices.
Temperature factors may be corrected to reflect the symmetry.
All constraints for expanded atoms are erased with the exception
of the occupancy("occ". Constraints of unaffected atoms are adjusted
for new positions self.initial.
spacegroup -- instance of Structure.SpaceGroup
indices -- list of integer indices of atoms to be expanded
sgoffset -- optional offset of space group origin [0,0,0]
"""
from diffpy.Structure.SymmetryUtilities import ExpandAsymmetricUnit
acd = self._popAtomConstraints()
# get unique, reverse sorted indices
ruindices = dict.fromkeys(indices).keys()
ruindices.sort()
ruindices.reverse()
coreatoms = [self.initial[i] for i in ruindices]
corepos = [a.xyz for a in coreatoms]
coreUijs = [a.U for a in coreatoms]
eau = ExpandAsymmetricUnit(spacegroup,
corepos,
coreUijs,
sgoffset=sgoffset,
eps=self.symposeps)
# build a nested list of new atoms:
newatoms = []
for i in range(len(coreatoms)):
ca = coreatoms[i]
caocc_con = None
if ca in acd and "occ" in acd[ca]:
caocc_con = acd[ca]["occ"]
eca = [] # expanded core atom
for j in range(eau.multiplicity[i]):
a = Atom(ca)
a.xyz = eau.expandedpos[i][j]
a.U = eau.expandedUijs[i][j]
eca.append(a)
if caocc_con is None: continue
# make a copy of occupancy constraint
acd[a] = {"occ": copy.copy(caocc_con)}
newatoms.append(eca)
# insert new atoms where they belong
for i, atomlist in zip(ruindices, newatoms):
self.initial[i:i + 1] = atomlist
# remember this spacegroup as the last one used
self.initial.pdffit["spcgr"] = spacegroup.short_name
self.initial.pdffit["sgoffset"] = list(sgoffset)
# tidy constraints
self._restoreAtomConstraints(acd)
return
def expandAsymmetricUnit(self, spacegroup, indices, sgoffset=[0, 0, 0]):
"""Perform symmetry expansion for atoms at given indices.
Temperature factors may be corrected to reflect the symmetry.
All constraints for expanded atoms are erased with the exception
of the occupancy("occ". Constraints of unaffected atoms are adjusted
for new positions self.initial.
spacegroup -- instance of Structure.SpaceGroup
indices -- list of integer indices of atoms to be expanded
sgoffset -- optional offset of space group origin [0,0,0]
"""
from diffpy.Structure.SymmetryUtilities import ExpandAsymmetricUnit
acd = self._popAtomConstraints()
# get unique, reverse sorted indices
ruindices = dict.fromkeys(indices).keys()
ruindices.sort()
ruindices.reverse()
coreatoms = [self.initial[i] for i in ruindices]
corepos = [a.xyz for a in coreatoms]
coreUijs = [a.U for a in coreatoms]
eau = ExpandAsymmetricUnit(spacegroup, corepos, coreUijs, sgoffset=sgoffset, eps=self.symposeps)
# build a nested list of new atoms:
newatoms = []
for i in range(len(coreatoms)):
ca = coreatoms[i]
caocc_con = None
if ca in acd and "occ" in acd[ca]:
caocc_con = acd[ca]["occ"]
eca = [] # expanded core atom
for j in range(eau.multiplicity[i]):
a = Atom(ca)
a.xyz = eau.expandedpos[i][j]
a.U = eau.expandedUijs[i][j]
eca.append(a)
if caocc_con is None:
continue
# make a copy of occupancy constraint
acd[a] = {"occ": copy.copy(caocc_con)}
newatoms.append(eca)
# insert new atoms where they belong
for i, atomlist in zip(ruindices, newatoms):
self.initial[i : i + 1] = atomlist
# remember this spacegroup as the last one used
self.initial.pdffit["spcgr"] = spacegroup.short_name
self.initial.pdffit["sgoffset"] = list(sgoffset)
# tidy constraints
self._restoreAtomConstraints(acd)
return
def test_insertAtoms(self):
"""check FitStructure.insertAtoms()
"""
from diffpy.Structure import Atom
stru = self.stru
stru.read(datafile('Ni.stru'), format='pdffit')
cns = Constraint('@1')
stru.constraints['x(2)'] = cns
stru.insertAtoms(0, [Atom('Na', (0, 0, 0))])
self.assertEqual(5, len(stru))
self.assertEqual(1, len(stru.constraints))
self.failUnless(cns is stru.constraints['x(3)'])
stru.insertAtoms(5, [Atom('Cl', (0, 0, 0))])
self.failUnless(['x(3)'] == stru.constraints.keys())
return
def test_pickling(self):
"""Test pickling of DiffpyStructureParSet.
"""
stru = Structure([Atom("C", [0, 0.2, 0.5])])
dsps = DiffpyStructureParSet("dsps", stru)
data = pickle.dumps(dsps)
dsps2 = pickle.loads(data)
self.assertEqual(1, len(dsps2.atoms))
self.assertEqual(0.2, dsps2.atoms[0].y.value)
return
def test___repr__(self):
"""Test representation of DiffpyStructureParSet objects.
"""
lat = Lattice(3, 3, 2, 90, 90, 90)
atom = Atom("C", [0, 0.2, 0.5])
stru = Structure([atom], lattice=lat)
dsps = DiffpyStructureParSet("dsps", stru)
self.assertEqual(repr(stru), repr(dsps))
self.assertEqual(repr(lat), repr(dsps.lattice))
self.assertEqual(repr(atom), repr(dsps.atoms[0]))
return
def test___init__(self):
"""check Structure.__init__()
"""
atoms = [Atom('C', [0, 0, 0]), Atom('C', [0.5, 0.5, 0.5])]
self.assertRaises(ValueError, Structure, atoms, filename=teifile)
self.assertRaises(ValueError,
Structure,
lattice=Lattice(),
filename=teifile)
self.assertRaises(ValueError,
Structure,
title='test',
filename=teifile)
stru1 = Structure(title='my title')
self.assertEqual('my title', stru1.title)
stru2a = Structure(atoms)
stru2b = Structure(iter(atoms))
stru2c = Structure(a for a in atoms)
s2a = str(stru2a)
self.assertEqual(s2a, str(stru2b))
self.assertEqual(s2a, str(stru2c))
return
def test___setslice__(self):
"""check Structure.__setslice__()
"""
a = Atom("Si", (0.1, 0.2, 0.3))
lat = self.stru.lattice
self.stru[:] = [a]
a0 = self.stru[0]
self.assertEqual(1, len(self.stru))
self.assertEqual('Si', a0.element)
self.failUnless(lat is a0.lattice)
self.failUnless(numpy.array_equal(a.xyz, a0.xyz))
self.failIf(a is a0)
self.failIf(lat is a.lattice)
return
def test_append(self):
"""check Structure.append()
"""
a = Atom("Si", (0.1, 0.2, 0.3))
lat = self.stru.lattice
self.stru.append(a)
alast = self.stru[-1]
self.assertEqual(3, len(self.stru))
self.assertEqual('Si', alast.element)
self.failUnless(lat is alast.lattice)
self.failUnless(numpy.array_equal(a.xyz, alast.xyz))
self.failIf(a is alast)
self.failIf(lat is a.lattice)
return
def test_insert(self):
"""check Structure.insert()
"""
a = Atom("Si", (0.1, 0.2, 0.3))
lat = self.stru.lattice
self.stru.insert(1, a)
a1 = self.stru[1]
self.assertEqual(3, len(self.stru))
self.assertEqual('Si', a1.element)
self.assertTrue(lat is a1.lattice)
self.assertTrue(numpy.array_equal(a.xyz, a1.xyz))
self.assertFalse(a is a1)
self.assertFalse(lat is a.lattice)
return
def test_setStructure(self):
"""check PairQuantity.setStructure()
"""
from diffpy.Structure import Structure, Atom
from diffpy.srreal.structureadapter import EMPTY
stru = Structure([Atom("Ar", [0.1, 0.2, 0.3])])
self.pq.setStructure(stru)
adpt = self.pq.getStructure()
self.assertEqual(1, adpt.countSites())
self.assertEqual("Ar", adpt.siteAtomType(0))
self.pq.setStructure(EMPTY)
adpt = self.pq.getStructure()
self.assertEqual(0, adpt.countSites())
return
def test___setitem__(self):
"""check Structure.__setitem__()
"""
a = Atom("Si", (0.1, 0.2, 0.3))
lat = self.stru.lattice
self.stru[1] = a
a1 = self.stru[1]
self.assertEqual(2, len(self.stru))
self.assertEqual('Si', a1.element)
self.failUnless(lat is a1.lattice)
self.failUnless(numpy.array_equal(a.xyz, a1.xyz))
self.failIf(a is a1)
self.failIf(lat is a.lattice)
return
def test_writeStr_rawxyz(self):
"""check writing of normal xyz file"""
stru = self.stru
stru.title = "test of writeStr"
stru.lattice = Lattice(1.0, 2.0, 3.0, 90.0, 90.0, 90.0)
# plain version
stru[:] = [Atom('H', [1., 1., 1.])]
s1 = stru.writeStr(self.format)
s1 = re.sub('[ \t]+', ' ', s1)
s0 = "H 1 2 3\n"
# brutal raw version
stru[0].element = ""
s1 = stru.writeStr(self.format)
s0 = "1 2 3\n"
self.assertEqual(s1, s0)
def test_getvar(self):
"""check PDFStructure.getvar()
"""
from diffpy.Structure import Atom
stru = self.stru
abcABG = (3.0, 4.0, 5.0, 81, 82, 83)
stru.lattice.setLatPar(*abcABG)
for i in range(6):
self.assertEqual(abcABG[i], stru.getvar('lat(%i)' % (i + 1)))
stru.append(Atom('Ni', [0.1, 0.2, 0.3]))
self.assertEqual(0.1, stru.getvar('x(1)'))
self.assertEqual(0.2, stru.getvar('y(1)'))
self.assertEqual(0.3, stru.getvar('z(1)'))
# spdiameter
self.assertEqual(0.0, stru.getvar('spdiameter'))
stru.pdffit['spdiameter'] = 37.7
self.assertEqual(37.7, stru.getvar('spdiameter'))
# stepcut
self.assertEqual(0.0, stru.getvar('stepcut'))
stru.pdffit['stepcut'] = 17.7
self.assertEqual(17.7, stru.getvar('stepcut'))
return
def bccFe():
atoms = [Atom('Fe', (0, 0, 0)), Atom('Fe', (0.5, 0.5, 0.5))]
a = 2.856
alpha = 90.
lattice = Lattice(a=a, b=a, c=a, alpha=alpha, beta=alpha, gamma=alpha)
return Structure(atoms, lattice, sgid=229)
def testDiffpyStructureParSet(self):
"""Test the structure conversion."""
a1 = Atom("Cu", xyz = numpy.array([.0, .1, .2]), Uisoequiv = 0.003)
a2 = Atom("Ag", xyz = numpy.array([.3, .4, .5]), Uisoequiv = 0.002)
l = Lattice(2.5, 2.5, 2.5, 90, 90, 90)
dsstru = Structure([a1,a2], l)
# Structure makes copies
a1 = dsstru[0]
a2 = dsstru[1]
s = DiffpyStructureParSet("CuAg", dsstru)
self.assertEquals(s.name, "CuAg")
def _testAtoms():
# Check the atoms thoroughly
self.assertEquals(a1.element, s.Cu0.element)
self.assertEquals(a2.element, s.Ag0.element)
self.assertEquals(a1.Uisoequiv, s.Cu0.Uiso.getValue())
self.assertEquals(a2.Uisoequiv, s.Ag0.Uiso.getValue())
self.assertEquals(a1.Bisoequiv, s.Cu0.Biso.getValue())
self.assertEquals(a2.Bisoequiv, s.Ag0.Biso.getValue())
for i in xrange(1,4):
for j in xrange(i,4):
uijstru = getattr(a1, "U%i%i"%(i,j))
uij = getattr(s.Cu0, "U%i%i"%(i,j)).getValue()
uji = getattr(s.Cu0, "U%i%i"%(j,i)).getValue()
self.assertEquals(uijstru, uij)
self.assertEquals(uijstru, uji)
bijstru = getattr(a1, "B%i%i"%(i,j))
bij = getattr(s.Cu0, "B%i%i"%(i,j)).getValue()
bji = getattr(s.Cu0, "B%i%i"%(j,i)).getValue()
self.assertEquals(bijstru, bij)
self.assertEquals(bijstru, bji)
self.assertEquals(a1.xyz[0], s.Cu0.x.getValue())
self.assertEquals(a1.xyz[1], s.Cu0.y.getValue())
self.assertEquals(a1.xyz[2], s.Cu0.z.getValue())
return
def _testLattice():
# Test the lattice
self.assertEquals(dsstru.lattice.a, s.lattice.a.getValue())
self.assertEquals(dsstru.lattice.b, s.lattice.b.getValue())
self.assertEquals(dsstru.lattice.c, s.lattice.c.getValue())
self.assertEquals(dsstru.lattice.alpha, s.lattice.alpha.getValue())
self.assertEquals(dsstru.lattice.beta, s.lattice.beta.getValue())
self.assertEquals(dsstru.lattice.gamma, s.lattice.gamma.getValue())
_testAtoms()
_testLattice()
# Now change some values from the diffpy Structure
a1.xyz[1] = 0.123
a1.U11 = 0.321
a1.B32 = 0.111
dsstru.lattice.setLatPar(a=3.0, gamma=121)
_testAtoms()
_testLattice()
# Now change values from the srfit DiffpyStructureParSet
s.Cu0.x.setValue(0.456)
s.Cu0.U22.setValue(0.441)
s.Cu0.B13.setValue(0.550)
d = dsstru.lattice.dist(a1.xyz, a2.xyz)
s.lattice.b.setValue(4.6)
s.lattice.alpha.setValue(91.3)
_testAtoms()
_testLattice()
# Make sure the distance changed
self.assertNotEquals(d, dsstru.lattice.dist(a1.xyz, a2.xyz))
return
def parseLines(self, lines):
"""Parse list of lines in atoms format.
Return Structure object or raise StructureFormatError.
"""
comlist = ["#", "%", "!", "*"]
atoms = []
title = ""
anext = False
sg = None
structure = BRAtomsStructure()
meta = structure.bratoms
pdict = dict.fromkeys(self.plist)
# Count the lines
ln = 0
try:
for line in lines:
ln += 1
# Strip comments from the line
for c in comlist:
idx = line.find(c)
if idx != -1:
line = line[:idx]
# Move on if there is not a line
if not line: continue
# Move on if there was only white space in the line
sline = line.split()
if not sline: continue
# Check if we have atoms following
if sline[0].startswith("atom"):
anext = True
continue
# Check for title
if sline[0].startswith("title"):
if title: title += "\n"
title += line[5:]
continue
# Get rid of pesky "=" and "," signs
while "=" in sline: sline.remove("=")
while "," in sline: sline.remove(",")
# space group
if sline and sline[0].startswith("space"):
meta["space"] = line[5:].strip()
continue
# output
if sline and sline[0].startswith("output"):
meta["output"] = line[6:].strip()
continue
# shift
if sline and sline[0].startswith("shift"):
meta["shift"] = line[5:].strip()
continue
# Check for other metadata
while sline and sline[0].strip() in meta:
key = sline.pop(0).strip()
if key == "central": key = "core"
meta[key] = sline.pop(0).strip()
# Check for lattice information.
while sline and sline[0].strip() in self.plist:
key = sline.pop(0).strip()
pdict[key] = float(sline.pop(0))
# Check for atom information
if sline and anext:
elraw = sline.pop(0).strip()
el = elraw[:1].upper() + elraw[1:].lower()
x = float(sline.pop(0))
y = float(sline.pop(0))
z = float(sline.pop(0))
tag = ""
if sline:
tag = sline.pop(0).strip()
occ = 1.0
if sline:
occ = float(sline.pop(0))
a = Atom( atype = el,
xyz = [x,y,z],
name = tag,
occupancy = occ)
atoms.append(a)
except (ValueError, IndexError), e:
emsg = "%d: file is not in Atoms format" % ln
raise StructureFormatError(emsg)
def parseLines(self, lines):
"""Parse list of lines in atoms format.
Return Structure object or raise StructureFormatError.
"""
comlist = ["#", "%", "!", "*"]
atoms = []
title = ""
anext = False
structure = BRAtomsStructure()
meta = structure.bratoms
pdict = dict.fromkeys(self.plist)
# Count the lines
ln = 0
try:
for line in lines:
ln += 1
# Strip comments from the line
for c in comlist:
idx = line.find(c)
if idx != -1:
line = line[:idx]
# Move on if there is not a line
if not line: continue
# Move on if there was only white space in the line
sline = line.split()
if not sline: continue
# Check if we have atoms following
if sline[0].startswith("atom"):
anext = True
continue
# Check for title
if sline[0].startswith("title"):
if title: title += "\n"
title += line[5:]
continue
# Get rid of pesky "=" and "," signs
while "=" in sline: sline.remove("=")
while "," in sline: sline.remove(",")
# space group
if sline and sline[0].startswith("space"):
meta["space"] = line[5:].strip()
continue
# output
if sline and sline[0].startswith("output"):
meta["output"] = line[6:].strip()
continue
# shift
if sline and sline[0].startswith("shift"):
meta["shift"] = line[5:].strip()
continue
# Check for other metadata
while sline and sline[0].strip() in meta:
key = sline.pop(0).strip()
if key == "central": key = "core"
meta[key] = sline.pop(0).strip()
# Check for lattice information.
while sline and sline[0].strip() in self.plist:
key = sline.pop(0).strip()
pdict[key] = float(sline.pop(0))
# Check for atom information
if sline and anext:
elraw = sline.pop(0).strip()
el = elraw[:1].upper() + elraw[1:].lower()
x = float(sline.pop(0))
y = float(sline.pop(0))
z = float(sline.pop(0))
tag = ""
if sline:
tag = sline.pop(0).strip()
occ = 1.0
if sline:
occ = float(sline.pop(0))
a = Atom(atype = el,
xyz = [x, y, z],
label = tag,
occupancy = occ)
atoms.append(a)
except (ValueError, IndexError):
emsg = "%d: file is not in Atoms format" % ln
raise StructureFormatError(emsg)
# Make sure we have atoms.
if len(atoms) == 0:
raise StructureFormatError("File contains no atoms")
# Make sure we have unit cell parameters
if pdict["a"] is None:
emsg = "Missing definition of cell parameter"
raise StructureFormatError(emsg)
# Fill in optional information if it was missing.
if pdict["alpha"] is None:
pdict["alpha"] = 90.0
if pdict["beta"] is None:
pdict["beta"] = pdict["alpha"]
if pdict["gamma"] is None:
pdict["gamma"] = pdict["alpha"]
if pdict["b"] is None:
pdict["b"] = pdict["a"]
if pdict["c"] is None:
pdict["c"] = pdict["a"]
if meta['core'] is None:
meta['core'] = atoms[0].element
lat = Lattice(**pdict)
structure.title = title
structure.lattice = lat
structure.extend(atoms)
return structure
def expandSuperCell(self, mno):
"""Perform supercell expansion for this structure and adjust
constraints for positions and lattice parameters. New lattice
parameters are multiplied and fractional coordinates divided by
corresponding multiplier. New atoms are grouped with their source
in the original cell.
mno -- tuple or list of three positive integer cell multipliers along
the a, b, c axis
"""
# check argument
if tuple(mno) == (1, 1, 1): return
if min(mno) < 1:
raise ControlValueError("mno must contain 3 positive integers")
# back to business
acd = self._popAtomConstraints()
mnofloats = numpy.array(mno[:3], dtype=float)
ijklist = [(i,j,k) for i in range(mno[0])
for j in range(mno[1]) for k in range(mno[2])]
# build a list of new atoms
newatoms = []
for a in self.initial:
for ijk in ijklist:
adup = Atom(a)
adup.xyz = (a.xyz + ijk)/mnofloats
newatoms.append(adup)
# does atom a have any constraint?
if a not in acd: continue
# add empty constraint dictionary for duplicate atom
acd[adup] = {}
for barevar, con in acd[a].iteritems():
formula = con.formula
if barevar in ("x", "y", "z"):
symidx = "xyz".index(barevar)
if ijk[symidx] != 0:
formula += " + %i" % ijk[symidx]
if mno[symidx] > 1:
formula = "(%s)/%.1f" % (formula, mno[symidx])
formula = re.sub(r'\((@\d+)\)', r'\1', formula)
# keep other formulas intact and add constraint
# for barevar of the duplicate atom
acd[adup][barevar] = Constraint(formula)
# replace original atoms with newatoms
self.initial[:] = newatoms
for ai, an in zip(self.initial, newatoms):
if an in acd:
acd[ai] = acd[an]
# and rebuild their constraints
self._restoreAtomConstraints(acd)
# take care of lattice parameters
self.initial.lattice.setLatPar(
a=mno[0]*self.initial.lattice.a,
b=mno[1]*self.initial.lattice.b,
c=mno[2]*self.initial.lattice.c )
# adjust lattice constraints if present
latvars = ( "lat(1)", "lat(2)", "lat(3)" )
for var, multiplier in zip(latvars, mno):
if var in self.constraints and multiplier > 1:
con = self.constraints[var]
formula = "%.0f*(%s)" % (multiplier, con.formula)
formula = re.sub(r'\((@\d+)\)', r'\1', formula)
con.formula = formula
return
def testDiffpyStructureParSet(self):
"""Test the structure conversion."""
a1 = Atom("Cu", xyz = numpy.array([.0, .1, .2]), Uisoequiv = 0.003)
a2 = Atom("Ag", xyz = numpy.array([.3, .4, .5]), Uisoequiv = 0.002)
l = Lattice(2.5, 2.5, 2.5, 90, 90, 90)
dsstru = Structure([a1,a2], l)
# Structure makes copies
a1 = dsstru[0]
a2 = dsstru[1]
s = DiffpyStructureParSet("CuAg", dsstru)
self.assertEquals(s.name, "CuAg")
def _testAtoms():
# Check the atoms thoroughly
self.assertEquals(a1.element, s.Cu0.element)
self.assertEquals(a2.element, s.Ag0.element)
self.assertEquals(a1.Uisoequiv, s.Cu0.Uiso.getValue())
self.assertEquals(a2.Uisoequiv, s.Ag0.Uiso.getValue())
self.assertEquals(a1.Bisoequiv, s.Cu0.Biso.getValue())
self.assertEquals(a2.Bisoequiv, s.Ag0.Biso.getValue())
for i in xrange(1,4):
for j in xrange(i,4):
uijstru = getattr(a1, "U%i%i"%(i,j))
uij = getattr(s.Cu0, "U%i%i"%(i,j)).getValue()
uji = getattr(s.Cu0, "U%i%i"%(j,i)).getValue()
self.assertEquals(uijstru, uij)
self.assertEquals(uijstru, uji)
bijstru = getattr(a1, "B%i%i"%(i,j))
bij = getattr(s.Cu0, "B%i%i"%(i,j)).getValue()
bji = getattr(s.Cu0, "B%i%i"%(j,i)).getValue()
self.assertEquals(bijstru, bij)
self.assertEquals(bijstru, bji)
self.assertEquals(a1.xyz[0], s.Cu0.x.getValue())
self.assertEquals(a1.xyz[1], s.Cu0.y.getValue())
self.assertEquals(a1.xyz[2], s.Cu0.z.getValue())
return
def _testLattice():
# Test the lattice
self.assertEquals(dsstru.lattice.a, s.lattice.a.getValue())
self.assertEquals(dsstru.lattice.b, s.lattice.b.getValue())
self.assertEquals(dsstru.lattice.c, s.lattice.c.getValue())
self.assertEquals(dsstru.lattice.alpha, s.lattice.alpha.getValue())
self.assertEquals(dsstru.lattice.beta, s.lattice.beta.getValue())
self.assertEquals(dsstru.lattice.gamma, s.lattice.gamma.getValue())
_testAtoms()
_testLattice()
# Now change some values from the diffpy Structure
a1.xyz[1] = 0.123
a1.U11 = 0.321
a1.B32 = 0.111
dsstru.lattice.setLatPar(a=3.0, gamma=121)
_testAtoms()
_testLattice()
# Now change values from the srfit DiffpyStructureParSet
s.Cu0.x.setValue(0.456)
s.Cu0.U22.setValue(0.441)
s.Cu0.B13.setValue(0.550)
d = dsstru.lattice.dist(a1.xyz, a2.xyz)
s.lattice.b.setValue(4.6)
s.lattice.alpha.setValue(91.3)
_testAtoms()
_testLattice()
# Make sure the distance changed
self.assertNotEquals(d, dsstru.lattice.dist(a1.xyz, a2.xyz))
return
def expandSuperCell(self, mno):
"""Perform supercell expansion for this structure and adjust
constraints for positions and lattice parameters. New lattice
parameters are multiplied and fractional coordinates divided by
corresponding multiplier. New atoms are grouped with their source
in the original cell.
mno -- tuple or list of three positive integer cell multipliers along
the a, b, c axis
"""
# check argument
if tuple(mno) == (1, 1, 1): return
if min(mno) < 1:
raise ControlValueError("mno must contain 3 positive integers")
# back to business
acd = self._popAtomConstraints()
mnofloats = numpy.array(mno[:3], dtype=float)
ijklist = [(i, j, k) for i in range(mno[0]) for j in range(mno[1])
for k in range(mno[2])]
# build a list of new atoms
newatoms = []
for a in self.initial:
for ijk in ijklist:
adup = Atom(a)
adup.xyz = (a.xyz + ijk) / mnofloats
newatoms.append(adup)
# does atom a have any constraint?
if a not in acd: continue
# add empty constraint dictionary for duplicate atom
acd[adup] = {}
for barevar, con in acd[a].iteritems():
formula = con.formula
if barevar in ("x", "y", "z"):
symidx = "xyz".index(barevar)
if ijk[symidx] != 0:
formula += " + %i" % ijk[symidx]
if mno[symidx] > 1:
formula = "(%s)/%.1f" % (formula, mno[symidx])
formula = re.sub(r'\((@\d+)\)', r'\1', formula)
# keep other formulas intact and add constraint
# for barevar of the duplicate atom
acd[adup][barevar] = Constraint(formula)
# replace original atoms with newatoms
self.initial[:] = newatoms
for ai, an in zip(self.initial, newatoms):
if an in acd:
acd[ai] = acd[an]
# and rebuild their constraints
self._restoreAtomConstraints(acd)
# take care of lattice parameters
self.initial.lattice.setLatPar(a=mno[0] * self.initial.lattice.a,
b=mno[1] * self.initial.lattice.b,
c=mno[2] * self.initial.lattice.c)
# adjust lattice constraints if present
latvars = ("lat(1)", "lat(2)", "lat(3)")
for var, multiplier in zip(latvars, mno):
if var in self.constraints and multiplier > 1:
con = self.constraints[var]
formula = "%.0f*(%s)" % (multiplier, con.formula)
formula = re.sub(r'\((@\d+)\)', r'\1', formula)
con.formula = formula
return
def carbonzchain(n):
"Helper function that returns a z-chain of Carbon atoms."
from diffpy.Structure import Structure, Atom
rv = Structure([Atom('C', [0, 0, z]) for z in range(n)])
return rv
