Chemical bond and entanglement of electrons in the hydrogen molecule

TL;DR

This paper analyzes quantum entanglement between electrons in the hydrogen molecule, finding that entanglement measures do not directly correlate with chemical bond formation.

Contribution

It provides an analytic expression for electron entanglement in H2 and demonstrates that entanglement is not directly related to chemical bonding.

Findings

Concurrence can be analytically expressed for H2's ground state.

Entanglement does not correlate with chemical bond formation.

The study clarifies the role of quantum correlations in molecular systems.

Abstract

We theoretically investigate the quantum correlations (in terms of concurrence of indistinguishable electrons) in a prototype molecular system (hydrogen molecule). With the assistance of the standard approximations of the linear combination of atomic orbitals and the configuration interaction methods we describe the electronic wavefunction of the ground state of the H2 molecule. Moreover, we managed to find a rather simple analytic expression for the concurrence (the most used measure of quantum entanglement) of the two electrons when the molecule is in its lowest energy. We have found that concurrence does not really show any relation to the construction of the chemical bond.