MOLPRO

47 POTENTIAL ENERGY SURFACES (SURF) 354
INFO=value
ment. Symmetry of the modes will be determined even if the NOSYM
keyword is used in the electronic structure calculations. In certain
cases numerical noise can be very high and thus prohibits a correct
determination of the symmetry labels. This is denoted by the label
Err for these modes. In such cases symmetry should be switched off
in the calculation of the potential energy surfaces and the VCI calculations,
because the results may be corrupted. Symmetry can be
switched off by using MPG=1.
INFO=1 provides a list of the values of all relevant program parameters
(options).
The following example shows the input of a calculation which computes energy and dipole
surfaces at the MP2/cc-pVTZ level and subsequently determines the anharmonic frequencies at
the VSCF and VCI levels. Hartree-Fock calculations will not be restarted and the .log-file is
directed to the scratch directory as defined by the $TMPDIR variable.
memory,20,m
geomtyp=xyz
orient,mass
geometry={
3
Water
O 0.0675762564 0.0000000000 -1.3259214590
H -0.4362118830 -0.7612267436 -1.7014971211
H -0.4362118830 0.7612267436 -1.7014971211
}
mass,iso
basis=vdz
logfile,scratch
hf
mp2
optg
{frequencies,symm=auto
print,low=50}
label1
{hf
start,atden}
{mp2
cphf,1}
surf,start1D=label1,dipole=1,sym=auto
vscf,dipole=1,combi=1
vci,dipole=1,version=3,combi=1
47.2 Multi-level calculations
VMULT,options
The level of the electronic structure calculations can be changed for the different i-body terms in
the expansion of the potential. As a consequence, the keywords START2D, START3D, VAR2D
and VAR3D exist in full analogy to the keywords START1D and VAR1D in standard calculations
(see above). The number always represents the level of the expansion term. Such calculations