  We present a theoretical study of electronic states in magnetic and
nonmagnetic semiconductor quantum wires. The effects of chemical and magnetic
disorder at paramagnetic temperatures are investigated in single-site coherent
potential approximation. It is shown that the nonmagnetic impurity shifts the
band of carriers and suppresses the van Hove singularities of the local density
of states (LDOS) depending on the value of impurity concentration. The magnetic
impurity, however, broadens the band which depends on the strength of exchange
coupling, and in the high impurity concentration, the van Hove singularities in
the LDOS can completely disappear and the curves become smooth.
