What is CCSL?

CCSL is a library of subroutines for doing crystallographic and related calculations. It is designed not so much as a set of programs for determining and refining structures, for which several other systems are available, but as toolbox to allow the crystallography of non-trivial structures to be easily introduced into user programs.

CCSL includes subroutines for:

	Crystal geometry and symmetry
	Data analysis : absorption, extinction etc.
	Structure factor calculations including multipole description of form-factors
	Fourier calculations
	Magnetic structures and structure factors
	Polarised neutron scattering
	Flexible least squares refinement
	etc.

The library was designed as a toolbox to allow users to build programs to meet their own special needs with the assurance that the crystallography will be; properly treated. There are however a set of main programs
included with the library which have proved generally useful. They can be used as they stand, or as models from which to develop new programs.

P.J. Brown - Institut Laue Langevin, Grenoble, FRANCE. e-mail brown@ill.fr