Paramagnetic adsorbates on graphene: a charge transfer analysis

TL;DR

This paper presents a modified Hirshfeld charge analysis method to accurately quantify charge transfer between paramagnetic molecules like NO2 and graphene, highlighting the importance of supercell size in ab initio calculations.

Contribution

A new charge analysis method tailored for paramagnetic adsorbates on graphene, improving accuracy in charge transfer calculations.

Findings

The modified Hirshfeld method provides accurate charge transfer results.

Supercell size significantly affects charge transfer calculations.

Implications for adsorption studies of paramagnetic molecules on graphene.

Abstract

We introduce a modified version of the Hirshfeld charge analysis method and demonstrate its accurateness by calculating the charge transfer between the paramagnetic molecule NO2 and graphene. The charge transfer between paramagnetic molecules and a graphene layer as calculated with ab initio methods can crucially depend on the size of the supercell used in the calculation. This has important consequences for adsorption studies involving paramagnetic molecules such as NO2 physisorbed on graphene or on carbon nanotubes.