DSR - Disordered Structure Refinement

Its main purpose is the transfer of molecular fragments to a user-defined location in the target structure. Writing a special DSR command into the SHELXL .res file of the target structure instructs DSR on where to place and how to orient a molecular fragment from the fragment database in the unit cell. In addition, it is possible to define the occupancy, residue or part number of the inserted fragment. The fragment can be inverted, e.g. to fit the second conformer of twisted tetrahydrofuran. If desired, automatically calculated distance restraints for all bonds in the molecular fragment can replace the restraints obtained from the database. Additional options in the system command line allow the import and export of molecular fragments to and from the database, and listing of and searching for database content.