Compressing multireference character of wave functions via fermionic mode optimization

TL;DR

This paper explores fermionic mode optimization within tensor network methods to effectively compress multireference wave functions by optimizing molecular orbitals to minimize entanglement, demonstrated through nitrogen dimer simulations.

Contribution

It introduces a method to compress multireference wave functions using fermionic mode optimization based on entanglement minimization.

Findings

Successful compression of wave functions for nitrogen dimer

Effective orbital optimization reduces entanglement

Potential for improved quantum chemistry simulations

Abstract

In this work, we present a brief overview of the fermionic mode optimization within the framework of tensor network state methods [PRL 117,210402(2016)], and demonstrate that it has the potential to compress the multireference character of the wave functions after finding optimal molecular orbitals (modes), based on entanglement minimization. Numerical simulations have been performed for the nitrogen dimer in the cc-pVDZ basis for the equilibrium and for stretched geometries.