Computation of Exchange Couplings by Means of an Exchange-Dedicated Perturbation Theory.

ABSTRACT: The accurate computation of high-spin/low-spin gaps remains a challenging task in computational chemistry, with significant implications for both theoretical studies and experimental applications. In this work, we present an exchange-dedicated perturbation theory (EDPT2) that allows an efficient calculation of exchange couplings in magnetic systems. Our approach builds on a previously developed second-order perturbative scheme based on de Loth's formalism but refines the treatment of singlet wave functions by explicitly incorporating ionic determinants in the zeroth-order description. The EDPT2 method is derived from a two-electron-two-center model and can be applied to multispin systems using minimal CAS-generated orbitals. A key advantage of EDPT2 lies in its computational efficiency, wi

SUBMITTER: Franz M 

PROVIDER: S-EPMC12461945 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature