def test_disp100(nq, ne):
"""Calculates the scattering intensity for phonon dispersions
for B2 FeAl along q // [100].
nq = number of q points to calculate.
ne = number of e points to calculate."""
uc = UnitCell( )
at1=Atom(symbol='Fe', mass=57) ; pos1=(0.0,0.0,0.0)
at2=Atom(symbol='Al') ; pos2=(0.5,0.5,0.5)
site1 = Site(pos1, at1)
site2 = Site(pos2, at2)
uc.addAtom( at1, pos1, "Fe1" )
uc.addAtom( at2, pos2, "Al1" )
print uc
kptlist = uc.getMonkhorstPackGrid((20,20,20)).reshape(8000,3)
sqecalc = AbInitio.kernelGenerator.SqeCalculator.SqeCalculator(uc, kpoints=kptlist)
sqecalc.readIDFeigenvectors(filename='polarizations.idf')
sqecalc.readEigenvaluesFromIDFomega2(filename='omega2s.idf')
sqecalc._DebyeWallerCalculator._energies = sqecalc._energies
sqecalc._DebyeWallerCalculator._polvecs = sqecalc._polvecs
estart = 0.0
deltae = 50.0 / ne
sqecalc._etransferTol = deltae
deltaqx = 3.0 / nq
sqecalc._qtransferTolRadius = deltaqx
qstart = numpy.array([0.0, 0.0, 0.0])
deltaq = numpy.array([deltaqx, 0.0, 0.0])
sqe = numpy.zeros((nq,ne), dtype='float')
for iq in range(nq):
for ie in range(ne):
qtransfer = qstart + iq * deltaq
etransfer = estart + ie * deltae
print "Q= %s , E= %s" % (qtransfer, etransfer)
sqe[iq,ie] = sqecalc.calcSqeCohCreateAllmodes(qtransfer, etransfer)
print "S(Q,E) = ", sqe[iq,ie]
pylab.imshow(sqe)
pylab.show()
end = raw_input()
return
def listOfAtom2UnitCell(loa):
"""Utility to convert a ListOfAtom instance to a UnitCell instance."""
import ASE.ListOfAtoms
import ASE.Atom
symbols = [x.symbol for x in loa]
cartpos = [x.position for x in loa]
cellvectors = loa.cell
uc = UnitCell()
uc.setCellVectors(cellvectors)
# note: by default, loa stores cartesian coordinates
fracpos = [uc.cartesianToFractional(x) for x in cartpos]
for n in range(len(symbols)):
atom = Atom(symbol=symbols[n])
uc.addAtom(atom, fracpos[n], '')
return uc
def listOfAtom2UnitCell(loa):
"""Utility to convert a ListOfAtom instance to a UnitCell instance."""
import ASE.ListOfAtoms
import ASE.Atom
symbols = [x.symbol for x in loa]
cartpos = [x.position for x in loa]
cellvectors = loa.cell
uc = UnitCell()
uc.setCellVectors(cellvectors)
# note: by default, loa stores cartesian coordinates
fracpos = [uc.cartesianToFractional(x) for x in cartpos]
for n in range(len(symbols)):
atom = Atom(symbol=symbols[n])
uc.addAtom(atom, fracpos[n], '')
return uc