Efficient simulation of inhomogeneously correlated systems using block interaction product states

TL;DR

This paper introduces a multi-configurational block interaction product state (BIPS) framework to efficiently simulate inhomogeneously correlated quantum systems, especially in large chemical systems with broad entanglement ranges.

Contribution

It presents a novel BIPS method that separately handles strong intra-fragment and weak inter-fragment correlations, improving accuracy and efficiency in quantum chemistry simulations.

Findings

High accuracy in chemical system simulations

Efficient handling of inhomogeneous correlations

Effective separation of intra- and inter-fragment correlations

Abstract

The strength of DMRG lies in its treatment of identical sites that are energetically degenerate and spatially similar. However, this becomes a drawback when applied to quantum chemistry calculations for large systems, as entangled orbitals often span broad ranges in energy and space, with notably inhomogeneous interactions. In this study, we propose addressing strong intra-fragment and weak inter-fragment correlations separately using a multi-configurational block interaction product state (BIPS) framework. The strong correlation is captured in electronic states on fragments, considering entanglement between fragments and their environments. This method has been tested in various chemical systems and shows high accuracy and efficiency in addressing inhomogeneous effects in quantum chemistry.