Derechos:Copyright (1993) American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article prepared in (Sejo, K.; Barandiaran, Z. and L.G.M. Pettersson. "Ab initio model potential study of pressure effects on K2NaGaF6:Cr3+." Journal of Chemical Physics 98.5 (1993): 4041-4046) and may be found at http://jcp.aip.org/resource/1/jcpsa6/v98/i5/p4041_s1