The Crunch homepage

The current version is 1.5, new options have been added since version 1.2. The new version, 1.5, requires a Fortran90 compiler and supports OpenMp and GPU calculations. Version 1.5 is significantly faster, speed increases of more than a factor of 4 have been found.

Solving the phaseproblem in crystallography is a necessary requirement for getting the molecular structure from your diffraction experiment. This is accomplished usually in one of two ways:
  1. Direct methods, based on statistic relations between structurefactors
  2. Patterson search methods.
Crunch is a direct methods program with a difference. Instead of using the usual triplet relation to determine the phases, Karle Hauptman matrices are used.
Please make your choice from the list given below.

The options
If you use Crunch, in any resulting publication please refer to:
Automatic Determination of Crystal Structures using Karle-Hauptman Matrices.
R. de Gelder, R.A.G. de Graaff & H. Schenk,
Acta Crystallographica A49 (1993), 287-293.

Image Rag
            Dr. R.A.G. de Graaff  
            The Leiden Institute of Chemistry 
            Gorlaeus Laboratories  
            University of Leiden
            PO box 9502
            2300 RA Leiden
            The Netherlands