Pa. Markowich et al., A WIGNER-FUNCTION APPROACH TO (SEMI)CLASSICAL LIMITS - ELECTRONS IN APERIODIC POTENTIAL, Journal of mathematical physics, 35(3), 1994, pp. 1066-1094
A rigorous derivation of the semiclassical Liouville equation for elec
trons which move in a crystal lattice (without the influence of an ext
ernal field) is presented herein. The approach is based on carrying ou
t the semiclassical limit in the band-structure Wigner equation. The s
emiclassical macroscopic densities are also obtained as limits of the
corresponding quantum quantities.