CRYSTAL: Package of programs, primarily for instructional purposes, to solve crystallographic problems of the sort detailed in Boisen and Gibbs (1985), "Mathematical Crystallography," Reviews in Mineralogy, v. 15, Mineral. Soc. Amer.

STRETCH (distributed with CRYSTAL): The program calculates O-H stretching frequencies for OH-bearing minerals.  Mainly for research.  Articles: Abbott (1991, 1992); Abbott, and Burnham (1992).  Abstracts: Abbott, and Burnham (1991).

QUICKSIT and QUICKMAP (distributed with CRYSTAL): QUICKSIT performs a search for an atom's minimum-energy position in the context of up to 100 neighboring atoms.  QUICKMAP performs energy calculations for individual sites or sites on a grid in the context  of up to 100 neighboring atoms.  Articles: Abbott (1990, 1992, 1994); Abbott, Burnham, and Post (1989); Abbott, Post, and Burnham (1989).  Abstracts: Abbott (1989); Abbott, Burnham, and Post (1989); Abbott, Post, and Burnham (1988).

Download CRYSTAL, STRETCH, QUICKSIT, QUICKMAP, with instructions and examples:  [IBM]

Theoretical Optical Crystallography:

OPT and OPTRFN: These are the first (and only?) available programs that successfully calculate principal refractive indices and orientation of the optical indicatrix for monoclinic and triclinic minerals from only unit-cell geometry, atomic coordinates, and electronic polarizabilities.  Mainly for research. Articles: Abbott (1993, 1994, 1996).  Abstracts: Abbott (1993, 1994, 1995).

Download OPT and OPTRFN, with instructions and examples: [IBM]

Download input files for application of OPT and OPTRFN to clinopyroxenes (Abbott, 1996): [IBM]