Gh. Grosch et al., GROUND-STATE PROPERTIES OF CDXSN1-XTE - THE ROLE OF D-ELECTRONS, International journal of quantum chemistry, 52(4), 1994, pp. 919-926
Within the framework of density functional theory (DFT), we calculate
the ground-state electronic properties of CdxSn1-xTe using norm-conser
ving pseudopotentials in connection with the local density (LDA) and v
irtual crystal approximation (VCA). Our particular interest is in the
influence of the Cd-4d and the Sn-4d electrons by comparing results ob
tained with pseudopotentials, which either consider the d-electrons ex
plicitly or in the frozen core. In the mixed crystal system CdxSn1-xTe
, the transition from a ten- (x = 0) to an eight-electron (x = 1) syst
em is realized, which is accompanied by a change of the crystal struct
ure from rock salt (SnTe) to zinc blende (CdTe). By calculating the gr
ound-state energies, we find the equilibrium lattice constants as the
function of x and the bulk modulus, as well as the crossover value of
x for the transition from rock-salt to zinc blende. The calculated lat
tice constants and bulk moduli are in much closer agreement with exper
imental data if the d-electrons are taken into account explicitly, whe
reas the crossover is rather insensitive with respect to the d-electro
ns. In view of the electronic charge density, we demonstrate the decre
ase of ionicity for increasing x. (C) 1994 John Wiley & Sons, Inc.