Multireference configuration interaction treatment of excited-state electron correlation in periodic systems: the band structure of trans-polyacetylene

TL;DR

This paper presents a systematic wave-function-based method using multireference configuration interaction to accurately predict the electronic band structure of periodic systems, demonstrated on trans-polyacetylene.

Contribution

It introduces a transferable effective Hamiltonian approach combined with MRCI calculations for periodic systems, enabling accurate band structure predictions from first principles.

Findings

Successfully predicts the band structure of trans-polyacetylene

Accounts for all correlation effects in valence and conduction bands

Provides a transferable method applicable to other non-conducting solids

Abstract

A systematic method to account for electron correlation in periodic systems which can predict quantitatively correct band structures of non-conducting solids from first principles is presented. Using localized Hartree-Fock orbitals (both occupied and virtual ones), an effective Hamiltonian is built up whose matrix elements can easily be transferred from finite to infinite systems. To describe the correlation effects wave-function-based multireference configuration interaction (MRCI) calculations with singly and doubly excited configurations are performed. This way it is possible to generate, both, valence and conduction bands with all correlation effects taken into account. Trans-polyacetylene is chosen as a test system.