The local electronic structure of alpha-Li3N

TL;DR

This study combines experimental and theoretical methods to analyze the local electronic structure of alpha-Li3N, revealing insights into its density of states, bonding character, and unoccupied electronic states with good agreement between data and models.

Contribution

It provides a comprehensive analysis of alpha-Li3N's electronic structure using novel RSFMS calculations and experimental techniques, clarifying bonding and electronic state characteristics.

Findings

Absence of covalent bonding character in alpha-Li3N.

Good agreement between experimental data and theoretical calculations.

Similar unoccupied local density of states for Li 1s and N 1s spectra.

Abstract

New theoretical and experimental investigation of the occupied and unoccupied local electronic density of states (DOS) are reported for alpha-Li3N. Band structure and density functional theory calculations confirm the absence of covalent bonding character. However, real-space full-multiple-scattering (RSFMS) calculations of the occupied local DOS finds less extreme nominal valences than have previously been proposed. Nonresonant inelastic x-ray scattering (NRIXS), RSFMS calculations, and calculations based on the Bethe-Salpeter equation are used to characterize the unoccupied electronic final states local to both the Li and N sites. There is good agreement between experiment and theory. Throughout the Li 1s near-edge region, both experiment and theory find strong similarities in the s- and p-type components of the unoccupied local final density of states projected onto an orbital angular momentum basis (l-DOS). An unexpected, significant correspondence exists between the near-edge spectra for the Li 1s and N 1s initial states. We argue that both spectra are sampling essentially the same final density of states due to the combination of long core-hole lifetimes, long photoelectron lifetimes, and the fact that orbital angular momentum is the same for all relevant initial states. Such considerations may be generically applicable for low atomic number compounds.