MOLPRO

49 THE VSCF PROGRAM (VSCF) 364
THERMO=value
ROTJ=value
DIPOLE=value
NDIM=value
NBAS=value
ORDPOL=val
ORDPROD=val
SHOW=value
INFO=value
SOLVER=1, calls the discrete variable representation (DVR) as proposed
by Hamilton and Light. Alternatively, the collocation algorithm
of Young and Peet can be used (SOLVER=2).
THERMO=1 allows for the improved calculation of thermodynamical
quantities (compare the THERMO keyword in combination with a harmonic
frequency calculation). However, the approach used here is an
approximation: While the harmonic approximation ist still retained
in the equation for the partition functions, the actual values of the
frequencies entering into these functions are the anharmonic values
derived from the VSCF calculation.
Rovibrational levels can be computed in an approximative fashion
only (this does not work in combination with the COMBI option).
Once the VSCF equations have been solved, the rotational constants
will be computed from the vibrationally averaged structures for each
vibrational level. This allows for a rough estimate and very fast calculation
of the rovibrational levels. ROTJ=n determines the value of
J. A negative number for J results in a calculation of all rovibrational
levels from J = 1 up to the specified J value.
DIPOLE=1 allows for the calculation of infrared intensities. Calculation
of infrared intensities requires the calculation of dipole surfaces
within the SURF program. By default intensities will not be computed.
The expansion of the potential in the VSCF calculation can differ from
the expansion in the SURF calculation. However, only values less or
equal to the one used in the surface calculation can be used.
The number of basis functions (distributed Gaussians) to be used for
solving the VSCF equations can controlled by NBAS=value. The default
is NBAS=20. This option is only active once a polynomial representation
of the potential has been chosen, see the option TYPE=POLY
and the POLY program.
Once the default value has been changed in the POLY program, this
value needs to be changed here as well.
Once the default value has been changed in the POLY program, this
value needs to be changed here as well.
SHOW=1 prints the effective 1D polynomials in case that the potential
is represented in terms of polynomials, see the option TYPE=POLY
and the POLY program.
INFO=1 provides a list of the values of all relevant program parameters
(options).