A first-principles study, using the local spin density approximation, to design materials with an isolated partially filled intermediate band, based on a II-VI semiconductor is presented. These materials, with an intermediate band of a metallic character, are of great interest as new high-efficiency materials in solar cells. The study presented in this work is based on X108Zn107M materials, where X = S, Te and M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni and Cu. The results show that the intermediate band is only present in some compounds. The electronic properties and the population analysis have been calculated and analyzed. (c) 2005 Elsevier B.V. All rights reserved.