Effective-mass reproducibility of the nearest-neighbor sp 3 s * models: Analytic results

We derive the exact expressions for the effective masses of the conduction and all three hole bands at G in the nearest-neighbor sps* model, both with and without the spin-orbit interaction. From these expressions we find that the nearest-neighbor sps* model can usually fit the electron mass better than the lightand heavyhole masses and will not be equally successful across a broad spectrum of materials. @S0163-1829 ~97!03432-2#