def main():
atoms = Molecule('h2',[(1,(1.,0,0)),(1,(-1.,0,0))])
bfs = getbasis(atoms)
nel = atoms.get_nel()
nbf = len(bfs)
nocc = nel/2
S,h,Ints = getints(bfs,atoms)
en,orbe,orbs = rhf(atoms,integrals=(S,h,Ints),)
emp2 = MP2(Ints,orbs,orbe,nocc,nbf-nocc)
return en+emp2
def main():
atoms = Molecule('He',
[(2,( .0000000000, .0000000000, .0000000000))],
units='Angstroms')
bfs = getbasis(atoms)
nel = atoms.get_nel()
nbf = len(bfs)
nocc = nel/2
S,h,Ints = getints(bfs,atoms)
en,orbe,orbs = rhf(atoms,integrals=(S,h,Ints))
emp2 = MP2(Ints,orbs,orbe,nocc,nbf-nocc)
return en+emp2
def main():
atoms = Molecule('h2', [(1, (1., 0, 0)), (1, (-1., 0, 0))])
bfs = getbasis(atoms)
nel = atoms.get_nel()
nbf = len(bfs)
nocc = nel / 2
S, h, Ints = getints(bfs, atoms)
en, orbe, orbs = rhf(
atoms,
integrals=(S, h, Ints),
)
emp2 = MP2(Ints, orbs, orbe, nocc, nbf - nocc)
return en + emp2
def main():
atoms = Molecule('ch4', [(6, (.0000000000, .0000000000, .0000000000)),
(1, (.0000000000, .0000000000, 1.0836058890)),
(1, (1.0216334297, .0000000000, -.3612019630)),
(1, (-.5108167148, .8847605034, -.3612019630)),
(1, (-.5108167148, -.8847605034, -.3612019630))],
units='Angstroms')
bfs = getbasis(atoms)
nel = atoms.get_nel()
nbf = len(bfs)
nocc = nel / 2
S, h, Ints = getints(bfs, atoms)
en, orbe, orbs = rhf(atoms, integrals=(S, h, Ints))
print "SCF completed, E = ", en
emp2 = MP2(Ints, orbs, orbe, nocc, nbf - nocc)
print "MP2 correction = ", emp2
print "Final energy = ", en + emp2
return en + emp2
def main():
atoms = Molecule('ch4',
[(6,( .0000000000, .0000000000, .0000000000)),
(1,( .0000000000, .0000000000,1.0836058890)),
(1,(1.0216334297, .0000000000,-.3612019630)),
(1,(-.5108167148, .8847605034,-.3612019630)),
(1,(-.5108167148,-.8847605034,-.3612019630))],
units='Angstroms')
bfs = getbasis(atoms)
nel = atoms.get_nel()
nbf = len(bfs)
nocc = nel/2
S,h,Ints = getints(bfs,atoms)
en,orbe,orbs = rhf(atoms,integrals=(S,h,Ints))
print "SCF completed, E = ",en
emp2 = MP2(Ints,orbs,orbe,nocc,nbf-nocc)
print "MP2 correction = ",emp2
print "Final energy = ",en+emp2
return en+emp2
# E.g. basis.bfs[0].powers (basis[0].powers)
# One can also access the contraction coefficients and the exponents of the
# PGBF making up the CGBF by doing
# basis[CGBF_n].pcoefs[PGBF_i]
# basis[CGBF_n].pexps[PGBF_i]
# Use "6-31g**" for "best" results
# Use "STO-3G" for debbuging
bas = getbasis(molec,basis_data="6-31g**")
# Grab length of basis and number of electrons and print - some of this
# obviously will not make sense if there's more than one type of atom
lenBasis = 2*len(bas)
nEle = molec.get_nel()
nucNum = nEle # Nuclear number - one of the reasons this only works
# for atoms.
# If we want molecules, we must be able to change this
# according to the molecule
lenNPartBasis = math.factorial(lenBasis)/(math.factorial(nEle) * \
math.factorial(lenBasis-nEle) )
print "\n"
print "Using a single particle spatial basis consisting of", lenBasis/2, \
"contracted gaussians."
print "Using a single particle basis length of", lenBasis, "."
print "The N particle basis has a length", lenNPartBasis, "."
# Let us now construct the spin-orbital basis. It will be a list consisting of
# tuples. Each element of the list is a spin-orbital and each tuple contains two
# values. A spin number (+1 or -1) and a CGBF object:
