Ab initio calculations of the electron structure of the compounds AgGaS2, CdGa2S4, InPS4

Crystalline structures of the compounds in the row AgGaS2-CdGa2S4-InPS4 originate from the sphalerite structure with the gradual growth of the deficiency of metallic atoms from defect-free (Ag4Ga4S8)-Ga-I-S-III to square(2)(II)Cd(2)(II)Ga(4)(III)S(8) and further to square(2)(III)In(2)(III)square(2)(V)P(2)(V)S(8), where the symbol square denotes a pseudovacancy. With the FEFF8 full multiple-scattering code, the local partial electron densities states of all atoms of all compounds investigated have been calculated. A comparison of the calculated electron densities with the experimental X-ray K- and L-2,L-3-spectra of emission and absorption of sulfur and phosphorus shows good correspondence between the form and energy positions of the fine structure elements. For the compounds investigated there is no significant influence of the defectiveness of the crystalline lattice on the electron density of states. (C) 2003 Elsevier Science Ltd. All rights reserved.