SparseMaps-A systematic infrastructure for reduced-scaling electronic structure methods. VI. Linear-scaling explicitly correlated N-electron valence state perturbation theory with pair natural orbital

Yang Guo; Fabijan Pavošević; Kantharuban Sivalingam; Ute Becker; Edward F Valeev; Frank Neese

doi:10.1063/5.0144260

SparseMaps-A systematic infrastructure for reduced-scaling electronic structure methods. VI. Linear-scaling explicitly correlated N-electron valence state perturbation theory with pair natural orbital

J Chem Phys. 2023 Mar 28;158(12):124120. doi: 10.1063/5.0144260.

Authors

Yang Guo¹, Fabijan Pavošević², Kantharuban Sivalingam³, Ute Becker³, Edward F Valeev⁴, Frank Neese³

Affiliations

¹ Qingdao Institute for Theoretical and Computational Sciences, Institute of Frontier and Interdisciplinary Science, Shandong University, Qingdao, Shandong 266237, China.
² Center for Computational Quantum Physics, Flatiron Institute, 162, 5th Ave., New York, New York 10010, USA.
³ Max Planck Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany.
⁴ Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, USA.

PMID: 37003738
DOI: 10.1063/5.0144260

Abstract

In this work, a linear scaling explicitly correlated N-electron valence state perturbation theory (NEVPT2-F12) is presented. By using the idea of a domain-based local pair natural orbital (DLPNO), computational scaling of the conventional NEVPT2-F12 is reduced to near-linear scaling. For low-lying excited states of organic molecules, the excitation energies predicted by DLPNO-NEVPT2-F12 are as accurate as the exact NEVPT2-F12 results. Some cluster models of rhodopsin are studied using the new algorithm. Our new method is able to study systems with more than 3300 basis functions and an active space containing 12 π-electrons and 12 π-orbitals. However, even larger calculations or active spaces would still be feasible.