Wavefunctions for large systems as basis for electronic structure calculations

TL;DR

This paper demonstrates that by employing cumulant techniques, wavefunctions can be effectively used for large solid systems, overcoming the exponential complexity barrier and enabling calculations for strongly correlated electrons.

Contribution

The authors introduce a cumulant-based approach that allows wavefunction methods to be applied to large systems, including strongly correlated materials, challenging previous limitations.

Findings

Wavefunctions for large systems are feasible with cumulant techniques.

The approach enables calculations for strongly correlated electrons.

Wavefunction-based methods can be extended to solids without exponential complexity.

Abstract

Electronic structure calculations for solids based on many-electron wavefunctions have been hampered by the argument that for large electron numbers wavefunctions are not a legitimate scientific concept, because they face an exponential wall problem. We show that this problem can be avoided by using cumulant techniques in formulating wavefunctions. Therefore calculations for solids based on many-electron functions are possible and useful. This includes also systems with strongly correlated electrons.