Electronic and structural properties of GaN by the full-potential linear muffin-tin orbitals method: The role of the d electrons
Abstract
The structural and electronic properties of cubic GaN are studied within the local-density approximation by the full-potential linear muffin-tin orbitals method. The Ga 3d electrons are treated as band states, and no shape approximation is made to the potential and charge density. The influence of d electrons on the band structure, charge density, and bonding properties is analyzed. Due to the energy resonance of Ga 3d states with nitrogen 2s states, the cation d bands are not inert, and features unusual for a III-V compound are found in the lower part of the valence band and in the valence charge density and density of states. To clarify the influence of the d states on the cohesive properties, additional full- and frozen-overlapped-core calculations were performed for GaN, cubic ZnS, GaAs, and Si. The results show, in addition to the known importance of core-valence exchange-correlation nonlinearity, that an explicit description of closed-shell interaction has a noticeable effect on the cohesive properties of GaN. Since its band structure and cohesive properties are sensitive to a proper treatment of the cation d bands, GaN appears to be somewhat exceptional among the III-V compounds and reminiscent of II-VI materials.
- Publication:
-
Physical Review B
- Pub Date:
- May 1993
- DOI:
- arXiv:
- arXiv:cond-mat/9208022
- Bibcode:
- 1993PhRvB..4713353F
- Keywords:
-
- 71.25.Tn;
- Condensed Matter
- E-Print:
- ( 20 REVTEX-preprint pages (REVTEX macros are included) 8 figures available upon request