symmetry for vibrations with NWChem Opt + Vib Freq calc

Post Reply
marsh
Posts: 3
Joined: Mon Jun 06, 2022 2:49 pm
Full Name: Anderson Marsh
Organization: Lebanon Valley College
Subdiscipline: physical chemistry

symmetry for vibrations with NWChem Opt + Vib Freq calc

Post by marsh »

Is there a way to get the irreducible representation to display in the output for an Opt + Vib Freq calculation with NWChem? I see that the point group is correct, but in the output table for vibrational modes the symmetry labels are missing.

polik
Posts: 22
Joined: Fri May 29, 2020 6:20 pm
Full Name: Will Polik
Organization: WebMO LLC

Re: symmetry for vibrations with NWChem Opt + Vib Freq calc

Post by polik »

WebMO output is based on the output file of the selected computational chemistry program.

In the case of NWChem, the output file contains the point group of the molecule and the symmetries of the molecular orbitals, but it does not contain the symmetries of the molecular vibrations. Therefore, WebMO can parse and display the molecule's point group and the MO symmetries, but not the vibrational normal mode symmetries.

To see this, click the "Raw Output" link after running Opt+Freq and Molecular Orbitals jobs on a small molecule like water.

Outputting the symmetries of normal mode vibrations would be a good request to make of the NWChem developers/maintainers!

Post Reply