Structure Model-Assembly Program

[Japanese]

The purpose of this program
When you study crystal structure of unknown powder material with Rietveld method, you need a structure model to start the calculation. Rietvelt method cannot solve the unknown structure, but refines a given structure. Usually, you must make a structure model by direct method with structure factor extracted from powder data or try-and-error method. This program, SMAP, will help you to make a structure model. It automatically finds unknown crystal structure on the basis of X-ray powder diffraction data, cell parameters, space group information, and number of atoms in a unit cell. This program assumes atomic coordinates by random number and selects good models by R-factor derived from the observed and calculated XRD pattern. You can solve the relatively simple oxide and silicate structure with a personal computer. As the diffraction data for the calculation is the set of d-value and relative intensity, you can solve the structure from a JCPDS card.

Download
The latest smap120.exe(1493KB) is here. This is a self-extracting file. Run the program in a directory and read manual_e.doc.

The unknown structure solved by SMAP
CaMg₂Al₆O₁₂
Miura,H., Hamada,Y., Suzuki, T., Akaogi, M.,Miyajima,N, and Fujino, K. (2000)
Crystal structure of the Al-rich new high pressure form.
American Mineralogist,85,1799-1803.[abstract]

Reference
Miura, H. and Kikuchi, T.(1999)
Crystal Structure Model-Assembly Program Using the Monte Carlo and the R-factor Method
Journal of Chemical Software,5,163-172. [abstrct]

Hiroyuki MIURA(1997)
A Crystal Structure Model Assembly Program using a Packing Analysis Method
Journal of the Ceramic Society of Japan,Int. Edition, 105,584-589.[abstract]

[Return by Browser's button]
the background show the crystal structure of CaMg₂Al₆O₁₂ , solved by SMAP. Green balls represent Ca atoms and blue represent Mg atoms. Octahedra represent [AlO₆].

The last update:2003-10-21