Пример #1
0
    def reduce(self, ibrav=None):
        """
        Reduces a structure instance with nonprimitive lattice ( i.e. solves
        for equivalent atomic positions) according to specified  lattice type (ibrav). 
        Each ibrav number corresponds to a specific primitive lattice 
        (see QE documentation).         
        """

        ib = self.lattice.ibrav
        if ibrav != None:
            ib = ibrav

        a = self.lattice.diffpy().a
        b = self.lattice.diffpy().b
        c = self.lattice.diffpy().c
        cAB = cosd(self.lattice.diffpy().gamma)
        cBC = cosd(self.lattice.diffpy().alpha)
        cAC = cosd(self.lattice.diffpy().beta)
        if ib > 0:
            qeLattice = QELattice(ibrav = ib, a = a, b = b, c = c,  cBC =  cBC, \
                              cAC = cAC, cAB = cAB)
        else:
            qeLattice = QELattice(ibrav=ib, base=self.lattice.base)

        qeLattice._qeInput = self._qeInput

        reducedStructure = QEStructure(self)

        reducedStructure.placeInLattice(qeLattice)

        # collect atoms that are at equivalent position to some previous atom
        duplicates = set([
            a1 for i0, a0 in enumerate(reducedStructure)
            for a1 in reducedStructure[i0 + 1:] if a0.element == a1.element
            and equalPositions(a0.xyz, a1.xyz, eps=1e-4)
        ])

        # Filter out duplicate atoms.  Use slice assignment so that
        # reducedStructure is not replaced with a list.
        self.lattice = qeLattice
        self[:] = [a for a in reducedStructure if not a in duplicates]

        self._qeInput.structure = self
        return
Пример #2
0
    def reduce(self, ibrav = None): 
        """
        Reduces a structure instance with nonprimitive lattice ( i.e. solves
        for equivalent atomic positions) according to specified  lattice type (ibrav). 
        Each ibrav number corresponds to a specific primitive lattice 
        (see QE documentation).         
        """
        
        ib = self.lattice.ibrav
        if ibrav != None:
            ib = ibrav            
        
        a = self.lattice.diffpy().a
        b = self.lattice.diffpy().b
        c = self.lattice.diffpy().c
        cAB = cosd(self.lattice.diffpy().gamma)
        cBC = cosd(self.lattice.diffpy().alpha)
        cAC = cosd(self.lattice.diffpy().beta)
        if ib > 0:
            qeLattice = QELattice(ibrav = ib, a = a, b = b, c = c,  cBC =  cBC, \
                              cAC = cAC, cAB = cAB)
        else:
            qeLattice = QELattice(ibrav = ib, base = self.lattice.base)            
     
        qeLattice._qeInput = self._qeInput
        
        reducedStructure = QEStructure(self)
        
        reducedStructure.placeInLattice( qeLattice )

        # collect atoms that are at equivalent position to some previous atom
        duplicates = set([a1
            for i0, a0 in enumerate(reducedStructure) for a1 in reducedStructure[i0+1:]
                if  a0.element == a1.element and equalPositions(a0.xyz, a1.xyz, eps=1e-4)])

        
        # Filter out duplicate atoms.  Use slice assignment so that
        # reducedStructure is not replaced with a list.
        self.lattice = qeLattice
        self[:] = [a for a in reducedStructure if not a in duplicates]        
        
        self._qeInput.structure = self
        return
Пример #3
0
    def _setReducedStructureFromDiffpyStructure(self,
                                                structure,
                                                ibrav,
                                                massList=[],
                                                psList=[]):
        """
        structure - diffpy.Structure object
        ibrav - Lattice index
        psList - list of strings with potential names
        diffpyStructure object will be modified with reduced atomic positions
        """
        import copy

        diffpyLattice = copy.deepcopy(structure.lattice)

        a = diffpyLattice.a
        b = diffpyLattice.b
        c = diffpyLattice.c
        cAB = cosd(diffpyLattice.gamma)
        cBC = cosd(diffpyLattice.alpha)
        cAC = cosd(diffpyLattice.beta)

        qeLattice = QELattice(ibrav = ibrav, a = a, b = b, c = c,  cBC =  cBC, \
                              cAC = cAC, cAB = cAB)

        qeLattice._qeInput = self._qeInput
        self.lattice = qeLattice
        # make a deep copy:
        reducedStructure = Structure(atoms=structure)

        reducedStructure.placeInLattice(Lattice(base=qeLattice.diffpy().base))

        # collect atoms that are at equivalent position to some previous atom
        duplicates = set([
            a1 for i0, a0 in enumerate(reducedStructure)
            for a1 in reducedStructure[i0 + 1:]
            if self._element(a0) == self._element(a1)
            and equalPositions(a0.xyz, a1.xyz, eps=1e-4)
        ])

        # Filter out duplicate atoms.  Use slice assignment so that
        # reducedStructure is not replaced with a list.
        reducedStructure[:] = [
            a for a in reducedStructure if not a in duplicates
        ]

        atomNames = []
        for a in reducedStructure:
            if self._element(a) not in atomNames:
                atomNames.append(self._element(a))

        atomicSpecies = {}
        for i, elem in enumerate(atomNames):
            if len(massList) - 1 < i:
                mass = 0
            else:
                mass = massList[i]
            if len(psList) - 1 < i:
                ps = ''
            else:
                ps = psList[i]
            atomicSpecies[elem] = (mass, ps)

        self[:] = []

        # convert to bohr units
        self.lattice.setLattice(ibrav, self.lattice.a*1.889725989, \
                                 self.lattice.b*1.889725989,
                                 self.lattice.c*1.889725989)

        for atom in reducedStructure:
            elem = self._element(atom)
            self.addNewAtom(atype = elem, xyz = atom.xyz, \
                            mass = atomicSpecies[elem][0], \
                            potential = atomicSpecies[elem][1],\
                            lattice = self.lattice, optConstraint = [])
Пример #4
0
    def _setReducedStructureFromDiffpyStructure(self, structure, ibrav, massList = [], psList = []):
        """
        structure - diffpy.Structure object
        ibrav - Lattice index
        psList - list of strings with potential names
        diffpyStructure object will be modified with reduced atomic positions
        """
        import copy

        diffpyLattice = copy.deepcopy(structure.lattice)

        a = diffpyLattice.a
        b = diffpyLattice.b
        c = diffpyLattice.c
        cAB = cosd(diffpyLattice.gamma)
        cBC = cosd(diffpyLattice.alpha)
        cAC = cosd(diffpyLattice.beta)

        qeLattice = QELattice(ibrav = ibrav, a = a, b = b, c = c,  cBC =  cBC, \
                              cAC = cAC, cAB = cAB)

        qeLattice._qeInput = self._qeInput
        self.lattice = qeLattice
        # make a deep copy:
        reducedStructure = Structure(atoms = structure)

        reducedStructure.placeInLattice(Lattice(base=qeLattice.diffpy().base))

        # collect atoms that are at equivalent position to some previous atom
        duplicates = set([a1
            for i0, a0 in enumerate(reducedStructure) for a1 in reducedStructure[i0+1:]
                if   self._element(a0) == self._element(a1) and equalPositions(a0.xyz, a1.xyz, eps=1e-4)])

        
        # Filter out duplicate atoms.  Use slice assignment so that
        # reducedStructure is not replaced with a list.
        reducedStructure[:] = [a for a in reducedStructure if not a in duplicates]

        atomNames = []
        for a in reducedStructure:
            if self._element(a) not in atomNames:
                atomNames.append(self._element(a))
        
        atomicSpecies = {}
        for i, elem in enumerate(atomNames):
            if len(massList) - 1 < i:
                mass = 0
            else:
                mass = massList[i]
            if len(psList) - 1 < i:
                ps = ''
            else:
                ps = psList[i]
            atomicSpecies[elem] =  (mass, ps)
               
        self[:] = []
        
        # convert to bohr units
        self.lattice.setLattice(ibrav, self.lattice.a*1.889725989, \
                                 self.lattice.b*1.889725989,
                                 self.lattice.c*1.889725989)

        for atom in reducedStructure:
            elem = self._element(atom)
            self.addNewAtom(atype = elem, xyz = atom.xyz, \
                            mass = atomicSpecies[elem][0], \
                            potential = atomicSpecies[elem][1],\
                            lattice = self.lattice, optConstraint = [])
Пример #5
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    def setReducedStructureFromDiffpyStructure(self, structure, ibrav, massList = [], psList = []):
        """
        structure - diffpy.Structure object
        ibrav - Lattice index
        psList - list of strings with pseudopotential names
        diffpyStructure object will be modified with reduced atomic positions
        """

        #self.atomicSpecies = OrderedDict()
        #self.optConstraints = []
        #self.atomicPositionsType = 'crystal'

        diffpyLattice = structure.lattice

        a = diffpyLattice.a
        b = diffpyLattice.b
        c = diffpyLattice.c
        cAB = cosd(diffpyLattice.gamma)
        cBC = cosd(diffpyLattice.alpha)
        cAC = cosd(diffpyLattice.beta)

        qeLattice = QELattice(ibrav = ibrav, a = a, b = b, c = c,  cBC =  cBC, \
                              cAC = cAC, cAB = cAB)

        self.lattice = qeLattice
        # make a deep copy (does not wok now)
        #reducedStructure = Structure(diffpyStructure)
        reducedStructure = structure

        reducedStructure.placeInLattice(Lattice(base=qeLattice.diffpy().base))

        # collect atoms that are at equivalent position to some previous atom
        duplicates = set([a1
            for i0, a0 in enumerate(reducedStructure) for a1 in reducedStructure[i0+1:]
                if   self._element(a0) == self._element(a1) and equalPositions(a0.xyz, a1.xyz, eps=1e-4)])

        
        # Filter out duplicate atoms.  Use slice assignment so that
        # reducedStructure is not replaced with a list.
        reducedStructure[:] = [a for a in reducedStructure if not a in duplicates]

        self.structure = reducedStructure

        atomNames = []
        for a in reducedStructure:
            if self._element(a) not in atomNames:
                atomNames.append(self._element(a))
        
        #print atomNames
        #print len(massList)
        for i, elem in enumerate(atomNames):
            if len(massList) - 1 < i:
                mass = 0
            else:
                mass = massList[i]
            if len(psList) - 1 < i:
                ps = ''
            else:
                ps = psList[i]      
            #print mass, ps
            # atomDict[a] = 
        # for i, atom in enumerate(reducedStructure):
            # elem = self._element(atom)
            # if len(massList) - 1 < i:
                # mass = 0
            # else:
                # mass = massList[i]
            # if len(psList) - 1 < i:
                # ps = ''
            # else:
                # ps = psList[i]            
            self.atomicSpecies[elem] =  AtomicSpecies(elem, mass, ps)
        
        for atom in reducedStructure:
            self.optConstraints.append([])

        # convert to bohr units
        self.lattice.setLattice(ibrav, self.lattice.a*1.889725989, \
                                 self.lattice.b*1.889725989,
                                 self.lattice.c*1.889725989)

        self.nat = len(reducedStructure)
        self.ntyp = len(self.atomicSpecies)
Пример #6
0
#!/usr/bin/env python

"""Express Ni FCC structure in its rhombohedral primitive cell.
"""

from diffpy.Structure import Structure
from diffpy.Structure import Lattice
from diffpy.Structure.SymmetryUtilities import equalPositions

# load Ni fcc structure, Ni.stru is in tests/testdata/
nifcc = Structure(filename='Ni.stru')
# base vectors for rhombohedral lattice in Cartesian coordinates
rhombbase = nifcc.lattice.cartesian(
    [[0.5, 0.5, 0.0], [0.0, 0.5, 0.5], [0.5, 0, 0.5]])

# make a deep copy of nifcc
nirhomb = Structure(nifcc)
nirhomb.placeInLattice(Lattice(base=rhombbase))

# collect atoms that are at equivalent position to some previous atom
duplicates = set([a1
    for i0, a0 in enumerate(nirhomb) for a1 in nirhomb[i0+1:]
        if equalPositions(a0.xyz, a1.xyz, eps=1e-4)])

# Filter out duplicate atoms.  Use slice assignment so that
# nirhomb is not replaced with a list.
nirhomb[:] = [a for a in nirhomb if not a in duplicates]

# use rstrip to avoid duplicate line feed
print nirhomb.writeStr(format='discus').rstrip()
Пример #7
0
#!/usr/bin/env python
"""Express Ni FCC structure in its rhombohedral primitive cell.
"""

from diffpy.Structure import Structure
from diffpy.Structure import Lattice
from diffpy.Structure.SymmetryUtilities import equalPositions

# load Ni fcc structure, Ni.stru is in tests/testdata/
nifcc = Structure(filename='Ni.stru')
# base vectors for rhombohedral lattice in Cartesian coordinates
rhombbase = nifcc.lattice.cartesian([[0.5, 0.5, 0.0], [0.0, 0.5, 0.5],
                                     [0.5, 0, 0.5]])

# make a deep copy of nifcc
nirhomb = Structure(nifcc)
nirhomb.placeInLattice(Lattice(base=rhombbase))

# collect atoms that are at equivalent position to some previous atom
duplicates = set([
    a1 for i0, a0 in enumerate(nirhomb) for a1 in nirhomb[i0 + 1:]
    if equalPositions(a0.xyz, a1.xyz, eps=1e-4)
])

# Filter out duplicate atoms.  Use slice assignment so that
# nirhomb is not replaced with a list.
nirhomb[:] = [a for a in nirhomb if not a in duplicates]

# use rstrip to avoid duplicate line feed
print nirhomb.writeStr(format='discus').rstrip()