On the calculation of complete dissociation curves of closed-shell pseudo-onedimensional systems through the multireference method of increments

TL;DR

This paper employs a multireference Method of Increments to accurately compute the dissociation curves of beryllium clusters, exploring size effects and the metal-insulator transition in one-dimensional systems.

Contribution

It introduces a multireference approach within the Method of Increments framework for calculating dissociation curves of closed-shell pseudo-one-dimensional systems, validated against DMRG benchmarks.

Findings

MoI provides reliable dissociation curves across the entire range.

Correlation energy exhibits size dependence useful for extrapolation.

Transition from metallic to insulating behavior analyzed through quantum chemistry.

Abstract

The Method of Increments (MoI) has been employed using a multireference approach to calculate the dissociation curve of beryllium ring-shaped clusters Be$_n$ of different sizes. Benchmarks obtained through different single and multireference methods including the ab initio Density Matrix Renormalization Group (DMRG) were used to verify the validity of the MoI truncation which showed a reliable behavior for the whole dissociation curve. Moreover we investigated the size dependence of the correlation energy at different distances in order to extrapolate the values for the periodic chain and to discuss the transition from a metal-like to a insulating-like behavior of the wave function through quantum chemical considerations.