VCROTATION is a program that can be used to calculate the Duschinsky rotation of a set of normal modes upon electronic excitation. From a consideration of the corresponding rotation matrix, the magnitude of the correlation of the ground state normal modes in a given electronically excited state may be assessed, and as such an informed decision of the choice of cuts to fit bilinear gamma and mu terms to made.

The VCROTATION program is command line driven and requires the specification of two quantum chemistry output files containing the results of frequency calculations for the ground state and the excited state under consideration.

The output of the program consists of the Duschinsky rotation and the rotated excited state Hessian given in terms of the ground state normal modes.

To run the program type
vcrotation arg1 arg2 ...
where arg1 arg2 ... are the arguments.

Arguments

Arguments
Argument Description
-g A A is name of the quantum chemistry output file containing the ground state normal modes
-e A A is name of the quantum chemistry output file containing the excited state normal modes
-nmodes N N is the number of normal modes
-o A A is name of the file to which the Duschinsky rotation matrix and rotated excited state Hessian will be written. If this is not specified, the filenam rotation.out will be used by default