An analysis of the fluorescence spectrum of neodymium chloride

Abstract

It is assumed that the effect of the surroundings of a neodymium ion in the trichloride lattice on the 4ƒ electrons can be reproduced by a static electric field. The electric potential is expanded in a series of spherical harmonics; because of the point symmetry C 3h only four terms are required. The observed splittings of 4 I 9/2 , 4 I 11/2 and 4 I 13/2 are fitted to within 2·5 cm -1 by varying the coefficients of the four spherical harmonics. The coefficients obtained thereby are compared to the corresponding ones for PrCl 3 , and the importance of configurational interaction is discussed. Intermediate coupling effects and crystal field interactions between the levels are taken into account in the calculations.