Comment on a Phys. Rev. Lett. paper: "All-Electron Self-Consistent GW Approximation: Application to Si, MnO, and NiO". Magnetic moment of NiO

TL;DR

This paper critiques a previous study on NiO's magnetic properties, emphasizing the importance of including spin-orbit coupling and orbital magnetism for accurate theoretical modeling.

Contribution

It highlights the necessity of considering spin-orbit coupling and orbital magnetism in theoretical approaches to 3d oxides like NiO.

Findings

Previous models used too small experimental magnetic moment values.

Corrected experimental value is 2.2 muB at 300 K, 2.6 muB at 0 K.

Neglecting spin-orbit coupling leads to physically inadequate results.

Abstract

We claim that any approach neglecting the spin-orbit coupling and the orbital magnetism is not physically adequate for 3d oxides, including NiO, and that in reaching "excellent agreement" in a Phys. Rev. Lett. 93, 126406 (2004) paper too small experimental value of 1.9 muB has been taken for the Ni magnetic moment despite publication of a new experimental value of 2.2 muB, at 300 K yielding 2.6 muB at T = 0 K, already in a year of 1998.