cRPA calculation of on-site and nearest neighbor Coulomb interaction of $LaNiO_2$

TL;DR

This paper uses first-principles cRPA calculations to quantify on-site and nearest neighbor Coulomb interactions in LaNiO2, revealing significant inter-plane correlations and frequency-dependent interaction strengths.

Contribution

It provides the first-principles estimation of Coulomb interactions in LaNiO2, highlighting the importance of non-local correlations and frequency dependence.

Findings

Nearest neighbor Coulomb interaction is about 25% of on-site at medium/high frequencies.

Inter-plane and intra-plane Coulomb interactions are of similar strength.

Frequency dependence of U(ω) indicates non-trivial dynamic correlations.

Abstract

We present first-principle calculation of the on-site and nearest neighbor Coulomb interaction strength of the Ni $d$ orbitals in bulk $LaNiO_{2}$, using the constrained Random Phase Approximation method. The nearest neighbor correlation within Ni-O plane turns out to be more significant when considering the frequency dependent $U(\omega)$, which can be as strong as about 25\% of the on-site value at medium and high frequencies. The inter Ni-O plane nearest neighbor correlation is found to be the same strength as that within the Ni-O plane, indicating the material is non-locally correlated also between the Ni-O planes.