Abstract
The present paper aims to study the electronic structure of semiconductors with d valence electrons such as CuX (X = Cl, Br or I). The full-potential linearized augmented-plane-wave method has been employed within the generalized gradient approximation for the exchange-correlation potential. The structural parameters have been obtained for the fundamental state of each CuX. Also, the role of d electrons and the contribution of every atomic orbital to the electronic structure are detailed and explained. From the obtained band structures, the electron (hole) valence and conduction effective masses are deduced. Our findings are compared with experimental and previous theoretical studies.