Multi-State Formulation of the Frozen-Density Embedding Quasi-Diabatization Approach

Abstract

We present a multi-state implementation of the recently developed FDE-diab methodology [J. Chem. Phys., 148 (2018), 214104] in the Serenity program. The new framework extends the original approach such that any number of charge-localized quasi-diabatic states can be coupled, giving an access to calculations of ground and excited state spin-density distributions as well as to excitation energies. We show that it is possible to obtain results similar to those from correlated wave function approaches such as the complete active space self-consistent field method at much lower computational effort. Additionally, we present a series of approximate computational schemes, which further decrease the overall computational cost and systematically converge to the full FDE-diab solution. The proposed methodology enables computational studies on spin-density distributions and related properties for large molecular systems of biochemical interest.

References in corpus (5)

• Spin in Density-Functional Theory
• Density functional theory embedding for correlated wavefunctions: Improved methods for open-shell systems and transition metal complexes
• Accurate ab initio spin densities
• An Accurate and Linear Scaling Method to Calculate Charge-Transfer Excitation Energies and Diabatic Couplings
• Hyperfine coupling constants from internally contracted multireference perturbation theory