The LMTRANS program reads the output of dipole matrix calculations and uses a given model potential calculated using the VCHFIT program to transform the dipole matrix to the diabatic representation.

The thus calculated diabatic dipole matrix and corresponding nuclear coordinates are written to a database that can then be used in a subsequent fitting procedure using the LMFIT program. For an input file named file.inp, the resulting database file will be named file.dat.

Additionally, the diabatic polarisability tensor can be calculated numerically at each geometry considered if the required output of dipole calculations performed with an applied electric field is also provided.

To run the program type
lmtrans input
or
lmtrans input.inp
where input (or input.inp) denotes the input file. The input format uses, like all the Quantics package input files, keywords that are for the most part free format and case insensitive. See Quantics input file structure

for further information on the general use of keywords, noting that there are no sections in the VCHAM input files. The input file ends with the keyword end-input


Structure of the LMTRANS input

The LMTRANS program requires the specification of a path to a .vcham file created using the VCHFIT program. Additionally, the normal modes used to construct the model VCHAM potential must be given via the specification of the path to a frequency calculation output file containing them.

Input Keywords
Keyword Description
vcham_file=S The model potential used to calculate the adiabatic-to-diabatic transformation is given in the .vcham file S
nmodes=N N is the number of normal modes
nstates=N N is the number of states
datadir = S Files are contained in the directory S. Default is "."
file=S The names quantum chemistry output files are given the file S
Defining the input data to be read from a MOLPRO output file.
abinitiotype = S Define the ab initio method used in the calculations to be read
S Method
CAS CASSCF
PT2 CASPT2
MRCI MRCI
EOM EOM-CCSD


Specification of the quantum chemistry output files

The specification of the quantum chemistry output files is achieved using the syntax

filename1
filename2
.
.
.
end-files

where each file contains the adiabatic dipole matrix calculated at a geometry of interest.

Additionally, the polarisability tensor can be calculated numerically. To do so, the following syntax must be used:

.
.
.
filename polar = pfile1 pfile2 pfile3 pfile4 pfile5 pfile6
.
.
.
end-files

Here, the files pfile1,..., pfile6 each contain contain the dipole matrix calculated at the same geometry as for the file filename but with an electric field applied in one of the x-, y-, or z-directions in either the positive or negative direction. The order of the specification of these files is arbitraty. The strength of the applied field in each of these six files must, of course, be the same.