45.3 Examples

The following input example (1) optimizes the geometry of water, (2) computes the harmonic frequencies, (3) generates a potential energy surface around the equilibrium structure, (4) computes the nuclear wave function and the infrared intensities at the VSCF level, and finally (5) performs three different VCI calculations using different configuration selection schemes. Vibrational angular momentum terms are included.

memory,20,m
basis=vdz
geomtyp=xyz
geometry={mass
   3
Water
O          0.0675762564        0.0000000000       -1.3259214590
H         -0.4362118830       -0.7612267436       -1.7014971211
H         -0.4362118830        0.7612267436       -1.7014971211
}

hf
mp2
optg
{frequencies,symm=auto
print,low=50}

label1
{hf
start,atden}
{mp2
cphf,1}

surf,start1D=label1,dipole=1,sym=auto
vscf,pmp=2,dipole=1
vci,pmp=3,dipole=1,version=1
vci,pmp=3,dipole=1,version=2
vci,pmp=3,dipole=1,version=3