Normal-coordinate analysis of the TiO6−5 ion

Abstract Normal-coordinate analysis for the TiO 6− 5 ion in M 2 TiO 5 (M = rare earths) has been made on the basis of C 4ν -symmetry and using the Wilson's GF matrix method. The observed frequencies have been quantitatively assigned according to the obtained values of the potential-energy distributions. Force constants for the different bonds and angles have been calculated. The TiO′ (axial) and TiO (equatorial) stretching force constants were calculated to be 4.15 and 2.48 mdyn A −1 , respectively.