Dirdif is a Patterson based structure solution program and should be considered the
program of first choice for heavy atom problems. Where a heavy atom problem can be consider a phase
containing Sulfur or Chlorine for many types of organics.
The latest Dirdif as of time of writing (October 1999) is DIRDIF 99.2. Dirdif 99.2 is available as binaries for Windows and DOS; and as source code for UNIX. To be fully functional, a licence file is required but should be inside the distribution (as of August 2002). If not, a zipped licence file can be obtained by clicking here.