For an input file named 'file.inp', an output file named 'file.out' is created that contains the optimised geometry in both Cartesian and normal mode coordinates. Additionally, a file named 'file.xyz' is created that contains the optimised geometry in xyz format for viewing.
To run the program typeor
vcmin input
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
vcmin input.inp
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
Input Syntax | ||
---|---|---|
Keyword | Description | |
geometry_define end-geometry_define |
The starting geometry (in xyz format) is given between these two keywords | |
file0 = S | S is the file containing the normal modes and reference geometry of the vibronic coupling Hamiltonian | |
vcham_file = S | S is the .vcham file created by VCHFIT | |
nstates = N | N is the number of states | |
sopt = N | N is the number of the state whose adiabatic potential is to be used in the optimisation | |
iter = N | N is the number of iterations to be used in the optimisation |
.vcham
file used is named all_fit.vcham. The normal
modes used are contained in the
file aniline_freq.log. The
starting geomerty in the optimisation is specified between the
lines geometry_define
and end-geometry_define
, and
corresponds to the reference geometry used in the fitting of the model
potential, which is the transition state for NH2 inversion in the
ground state. The line sopt = 1
selects the potential surface
of the ground state to perform the optimisation on. Running
vcmin vcmin_aniline.inp
results in the production of the output file vcmin_aniline.out, which contains the geometries of the starting and optimised geometries in both Cartesian and normal mode coordinates. Additionally the xyz file vcmin_aniline.xyz is produced, which contains the Cartesian coordinates of the optimised geometry for viewing purposes.