14 Interface to molecular visualization software

For the visualization of molecular structures, molecular orbitals, electron densities, geometry optimization steps, normal modes, and IR spectra an interface has been developed to the Molden program [139]. Cartesian coordinates, basis function information, MO coefficients, etc. are saved to file MOLDEN using Molden format. After the termination of Mrcc, Molden should be started by typing molden MOLDEN. The Molden interface can be controlled by the molden keyword (see page 12 for the description of the keyword).

If the MOs are localized, the MOLDEN file containing the canonical HF orbitals is saved under the name MOLDEN.CAN, and the canonical MOs are replaced by the localized ones in the MOLDEN file. You can use both files to visualize the MOs that you are interested in.

Please note that Molden can also be used for the generation of input molecular structures in Z-matrix or xyz format (see the description of the geom keyword on page 12).

Cartesian coordinates are also written to file COORD.xyz in xyz (XMol) format, which can be processed by many molecular visualization programs. This interface can also be controlled by the molden keyword (see page 12 for the description of the keyword).