  We report calculated, electronic and related properties of wurtzite and zinc
blende gallium nitrides (w-GaN, zb-GaN). We employed a local density
approximation (LDA) potential and the linear combination of atomic orbital
(LCAO) formalism. The implementation of this formalism followed the Bagayoko,
Zhao, and Williams (BZW) method, as enhanced by Ekuma and Franklin (BZW-EF).
The calculated electronic and related properties, for both structures of GaN,
are in good agreement with corresponding, experimental data, unlike results
from most previous ab initio calculations utilizing a density functional theory
(DFT) potential. These results include the electronic energy bands, the total
and partial densities of states (DOS and pDOS), and effective masses for both
structures. The calculated band gap of 3.29 eV, for w-GaN, is in agreement with
experiment and is an average of 1.0 eV larger than most previous ab-initio DFT
results. Similarly, the calculated band gap of zb-GaN of 2.9 eV, for a room
temperature lattice constant, is the ab-initio DFT result closest to the
experimental value.
