Powder XRD and optical absorption studies of Ce-containing Ca1-xSrxF2 single crystals (0.007 <= x <= 0.674) allowed to obtain the x-dependencies of the crystal unit cell parameter and of the position and intensity of the Ce3+-absorption peak near 306 nm. These dependencies were fitted with simple linear and/or exponential functions, which made it possible to obtain relationships between optical and structural parameters of the crystals. Based on this, possibilities are suggested for determining optical from structural parameters and vice versa in this material. (C) 2008 Elsevier B.V. All rights reserved.