Stochastic-SplitGAS: A Quantum Monte Carlo Multi-Reference Perturbation Theory Based on the Imaginary-Time Evolution of Effective Hamiltonians.

ABSTRACT: Accurately modeling the electronic structure of systems with many unpaired electrons remains a major challenge in quantum chemistry. Qualitatively correct electronic structures generally require large active space multireference wave functions, while dynamic correlation effects beyond the active space are crucial for quantitatively accurate descriptions of magnetic, catalytic and optical properties of such systems. Here, we present an uncontracted multireference perturbation theory based on the FCIQMC imaginary-time evolution of effective Hamiltonians, built upon the generalized active space concept and Löwdin's partitioning technique. The configurational interaction space is split into a reference space, consisting of the most important configurations, and a perturber space, containing th

SUBMITTER: Bonfirraro L 

PROVIDER: S-EPMC12746464 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature