SPECTRE
SPECTRE is a program for calculating spectroscopic and single-ion magnetic properties of rare-earth ions in crystals. The calculation employs intermediate coupling basis states, and allows mixing of all terms within the fn configuration. The program includes a facility for fitting crystal field parameters to sets of energy levels and transition intensities for one or more ions.
A full description of the software is given in the user guide.
Further information can be obtained from Andrew Boothroyd.