B. Freytag, AB-INITIO CALCULATION FOR MGTE AND TRANSITION OF MGXCD1-XTE FROM DIRECT TO INDIRECT SEMICONDUCTOR, Journal of physics. Condensed matter, 6(46), 1994, pp. 9875-9880
The ternary mixed crystal system MgxCd1-xTe has recently attracted int
erest as a basic material for the blue laser diode. We use norm-conser
ving pseudopotentials in connection with the local-density approximati
on for ab initio calculations of the stable crystal structure and the
lattice constant. Our results are in quantitative agreement with struc
tural properties. The electronic band structure is calculated in depen
dence on the composition x of the system by the virtual-crystal approx
imation (VCA). We find a transition from direct to indirect energy gap
for x = 0.7 in accordance with experimental data.