Modelling Electron Transfers Using Quasidiabatic Hartree-Fock States

TL;DR

This paper presents a method using quasidiabatic Hartree-Fock states and non-orthogonal configuration interaction to model and analyze electron transfer processes efficiently, demonstrated on a solar cell model.

Contribution

It introduces a novel approach combining Hartree-Fock solutions with non-orthogonal CI to study electron transfer, reducing computational complexity.

Findings

Accurately describes electron transfer in a titanium-alizarin complex

Provides insights into electronic states involved in transfer

Demonstrates effectiveness of the method for solar cell systems

Abstract

Electron transfer processes are ubiquitous in chemistry and of great importance in many systems of biological and commercial interest. The ab-initio description of these processes remains a challenge in theoretical chemistry, partly due to the high scaling of many post-Hartree--Fock computational methods. This poses a problem for systems of interest that are not easily investigated experimentally. We show that readily available Hartree--Fock solutions can be used as a quasidiabatic basis to understand electron transfer reactions in a Marcus framework. Non-orthogonal configuration interaction calculations can be used to quantify interactions between the resulting electronic states, and to investigate the adiabatic electron transfer process. When applied to a titanium-alizarin complex used as a model of a Gr\"atzel-type solar cell, this approach yields a correct description of the electron transfer and provides information about the electronic states involved in the process.