MultiState@GWEV

The MultiState@GWEV (or MS@GWEV) program is an interface to Gaussian 16 (through the keyword External) to calculate spin-forbidden reactions involving multiple spin states.

Recent Changes

05/16/2026

1. Bug fix for the calculation of q-vector.

2. In the calculation template, you can replace the keyword Guess=Read with Iop(4/5=100,5/38=6), thereby avoiding errors and interruptions when no wave function exists in the checkpoint file. See templet-o2 for an example and also the following notes.

Notes

For transition-metal systems, the default initial guess may not correspond to the lowest state. It is still recommended to first find the lowest-energy wavefunction for each spin state by performing some Stable calculations (saved in a checkpoint file), and then read it in using Guess=Read during optimization and frequency calculations.

04/20/2023

1. Bug fix for the default chi value.

2. Bug fix for the ONIOM calculation by Gaussian 16.c.

3. Single spin state calculation may be performed through -nst 1.

Citation

Please cite the following paper if you use this program.

• L. Zhao and W. Zou, A general method for locating stationary points on the mixed-spin surface of spin-forbidden reaction with multiple spin states, J. Chem. Phys. 158, 224110 (2023). doi

The closely related two-state spin-mixing model may be found in the following papers.

• B. Yang, L. Gagliardi, and D. G. Truhlar, Transition states of spin-forbidden reactions, Phys. Chem. Chem. Phys. 20, 4129 (2018). doi
• T. Takayanagi and T. Nakatomi, Automated reaction path searches for spin-forbidden reactions, J. Comput. Chem. 39, 1319 (2018). doi