Substitution effect on the crystallographic structure in Ca10-xSrx(PO4)(6)F-2 solid solution are studied by X-ray diffraction patterns and Rietveld refinements. Full potential electronic structure calculations based on LCAO (linear combination atomic orbital) are also performed using the obtained crystallographic parameters. DOS modification and the charge transfer are estimated versus the calcium content. According to the complex impedance method, ionic conductivity changes are explained. (c) 2009 Elsevier Ltd. All rights reserved.