Systematic QSGW calculations on the electronic structure of rare-earth nitrides

Rare-earth (RE) based light emitting materials are distinguished for their narrow line width, small temperature dependence and insensitivity to the environment. These characteristic properties mostly come from localized nature of 4f-states. Therefore, for accurate prediction and design of RE related functional material, reasonable description of 4f-states is indispensable.
In this paper, we present systematic electronic structure calculations of RE nitrides by using quasi-particle self-consistent GW (QSGW) method. This method was implemented to ecalj package, and confirmed to give reasonable description of the electronic structure of several materials including f-electron systems [1, 2]. It is found that the present calculations reproduce previous LDA+U calculations [3] and calculated magnetic moments are reasonably described by the Hund’s rule for most of the rare-earth nitrides. For example, SmN is calculated to be semi-metallic and predicted magnetic moments (S=2.50, L=4.96, J=2.46) are consistent to Hund’s rule prediction.
[1] D. Deguchi et al., JJAP. 55, 51201 (2016). [2] A. N. Chantis et al., PRB 76, 165126 (2007). [3] P. Larson and W. R. L. Lambrecht, PRB 75, 045114 (2007).