Modify the format of the F-matrix

The program fmat_setup is used to modify the format of the F-matrix so that it can be used in fcartp.

Running fmat_setup

The fmat_setup program will prompt the user for

print *,'Enter filename for Cartesian force constants: '

read(5,*) fname

h2o_631g.cmat

print *,'Enter number of atoms: '

read(5,*) iatom

3

print *,'Enter filename for dipole derivatives: '

read(5,*) fname

h2o_631g.dd

print *,'Enter number of symmetry blocks: '

read(5,*) isym

2

For water there are two symmetry blocks A1 and B2. These will be used in different data blocks in the fcartp input file. The program fcartp requires the Cartesian force constants and dipole derivatives to be repeated for each data block. This is done automatically in fmat_setup once you specify the number of symmetry blocks.