DIMS Direct Methods for Incommensurate Modulated/Composite Structures
- Operating systems: UNIX, Windows95, 98, NT, 2000 and XP
- DIMS (Direct-methods for Incomensurate Modulated Structures) deals with one-dimensionally modulated structures and composite structures consists of two sub-systems. For incommensurate modulated structures, the program calculates E-values independent of atomic scattering factors, hence it can accept diffraction data from X-rays, electrons or neutrons and treat them in the same way. However, for composite structures DIMS can deal with only X-ray diffraction data.
- Stand-alone version:
- The program is written in Fortran. In theory, it can be run in any operating system provided appropriate Fortran compiler is available.
- The program accepts two-line symbols of superspace groups (one-line symbols can be converted to two-line symbols by the program symbol1to2 described in Tutorial) and derives accordingly symmetry generators. Alternatively, it allows also manual input of symmetry generators.
- Incommensurate modulated/composite structures are solved by direct methods in two stages. In the first stage, phases of main reflections are derived using a conventional direct-method, while in the second stage, phases of satellite reflections are derived by a multi-dimensional direct method with starting phases of main reflections.
- In case the basic/average structure is known, phases of main reflections calculated from which can be input to DIMS and the first stage should be skipped.
- Windows version:
- The Windows version of DIMS forms a part of the program VEC.
- I/O data of DIMS can be displayed and manipulated by the sophisticated graphic interface of VEC. 4D-Fourier maps phased by DIMS can be calculated, displayed and interpreted within VEC. The subroutine MIMS can help with building a 4D-structure model from the 4D-Fourier map.
- Tutorial at http://cryst.iphy.ac.cn/VEC/Tutorials/DIMS/main.html
- Download at http://cryst.iphy.ac.cn/Download/download.html
- Contact: fan@aphy.iphy.ac.cn
