BonnMag: Computer program for ligand-field analysis of fn systems within the angular overlap model

The program BonnMag has been developed to calculate the absorption spectra and temperature dependent magnetic susceptibilities of f(n) systems. The computations of the transition energies are performed within the angular overlap model. Using Judd-Ofelt theory BonnMag allows estimation of the relative absorption coefficients of the electronic transitions with reasonable accuracy. A description of the theoretical background of the implemented methods is given. Using Slater-Condon-Shortley parameters and spin-orbit coupling coefficients for free Ln(3+) ions from ab initio calculations, the transition energies of all Ln(3+) ions are calculated and compared to the results from CASSCF/NEV-PT2 calculations. Splitting due to the ligand field as well as transition energies of all Cs(2)NaLnCl(6) (except Gd and Pm) are calculated using parameters reported in the literature. Based on the comparison between theory and experiment, the potential and limitations of the program BonnMag are shown. (c) 2017 Wiley Periodicals, Inc.