Orthogonality constrained density functional theory (OCDFT) and near-edge X-ray absorption (NEXAS) spectra

Hi All,

I found/read a interesting paper in JCTC :Predicting Near Edge X-ray Absorption Spectra with the Spin-Free Exact-Two-Component Hamiltonian and Orthogonality Constrained Density Functional Theory

The code used in this paper is the great Psi4, I want to know that this X2C-OCDFT NEXAS spectra calculation could be performed by the recent version of Psi4?

Because I can not find any OCDFT related information in Psi4 manual.

I believe they use a plugin for OCDFT. @francesco should be able to help you with details.

Hello @chrinide, glad to hear you found our paper interesting. I worked on that project during grad school. I can confirm that we did implement OCDFT as a PSI4 plugin. The current version of the code is maintained on GitHub (https://github.com/evangelistalab/ocdft). The scalar relativistic Hamiltonians necessary to perform x2c-ocdft calculations are in the main PSI4 code, how to use those are documented here (http://www.psicode.org/psi4manual/master/relativistic.html).

I have been out of the group for some years now and haven’t used OCDFT since, so @francesco will have to help you further.