Assignment of excitonic insulators in \textit{ab initio} theories: the case of NiBr${}_2$

Stefano Di Sabatino, Alejandro Molina-Sánchez, Pina Romaniello +1

In this work we perform a detailed first-principles analysis of the electronic and optical properties of NiBr${}_2$ within the state-of-the-art $GW$+BSE scheme to determine whether t…