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DS5 DS*SYSTEM4 DS*SYSTEM3 DS*SYSTEM2 DS*SYSTEM1 Application

According to 32 bit operating systems and expanding LSI technologies, the DIRECT-SEARCHER automatic system version 5 (DS5, 2005) has been developed for the crystal structure analysis of organic compounds running on PCs.
An organic chemist as well as a crystallographer can get results very easily with his own well-known PC. This DS5 is one program that consists of 19 crystallographic programs of the DS*SYSTEM4 running on Windows 2000 and XP.

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Version 5
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New developed DS5 (Direct-Searcher automatic system version 5) for the crystal structure analysis of small molecules running on personal computers (PCs) is one program that is integrated into one from more than twenty main programs, subroutine and mathematics/graphic libraries of the DS*SYSTEM4. Three features of the DS5 are: input instruction data have compatibilities with Shelx series, calculation sequences are controlled by subprogram names that are prepared by user, and graphical outputs are drawn on PC display with Postscript/HP-GL files. All functions of the DS5 are inherited from of the DS*SYSTEM4.

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Version 4
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The structure of DS*SYSTEM version 4 (DS*SYSTEM4) has the same layered approach as DS*SYSTEM3 and consists of more than twenty main programs and subroutine libraries. The main new features of DS*SYSTEM4 are: develop a new phase solver ShakePSD (Shake Patterson, Search and Direct methods), update a least-squares program LSBF to refining on |Fo(h)| or Fo(h)2 considering anomalous dispersion terms, adapt the interface to/from other program systems, and prepare Postscript and HP-GL files for graphical output on MS-Windows 95/98 and NT 3.x/4.0/5.0 operating systems. ShakePSD becomes an automatic general phase solver being able to handle both heavy-atom methods and direct methods within one program, and finds out with certainty molecule fragments. The revised LSBF program refines atomic parameters by the least-squares method with the block-diagonal or the full-matrix approximations which treat anomalous dispersions, refining on |Fo(h)| and Fo(h)2. Several practical tests are performed for these differentiations.

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Version 3
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The DS*SYSTEM3 consists of more than twenty main programs and subroutine libraries, and is created using the layered approach. The bottom layer is the operating system. The utility layer consists of the subroutine libraries, and all subprograms are grouped into common and individual libraries. The application layer consists of main programs which have entries for calculation or drawing.
The DS*SYSTEM3 reduces the limitation of several data loosely for the 32 bit operating system and adapts the data base of space group and atomic scattering factor tables [3-1,3-2].

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Version 2
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The PC and WS versions of the DS*SYSTEM version 2 (DS*SYSTEM2) were designed to operate in an interactive environment, and the large computer version runs in batch mode processing. These versions have the same capability, and the same input/output data structures. A chemist can select the platform according to the compound size.
The DS*SYSTEM3 was installed primarily on a PC, and four programs (DIRECTER, LSBF, SEARCHER, SFFR) that use CPU time intensively ran on a HP9000/700 (HP-UX) and IBM3090-200E (MVS/XA) [2-1]. The DS*SYSTEM2 havs been modified to change the algorithms of peak summation in the Fourier synthesis, to achieve a reduction of calculation time and better conform to user requirements.

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Version 1
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The first version of DS*SYSTEM was developed first for mainframe computers CDC3600/CDC6600 [1-1,1-2]. Next we have improved upon supercomputer Cray-1 [1-3,1-4] by adding vector facilities and optimizations, rewritten in Fortran77 and implemented on 32 bit PCs with several modifications and corrections of program code [1-5,1-6}.

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Applications
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We have solved more than 30 organic compounds by heavy-atom analysis and more 40 compounds by direct-methods. These programs have been successful over a considerable range of normal space groups (P -1, P 21/c, P 21, Pbca, P 212121 and etc.).

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Program Availability
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The DS5 has been fully tested under MS-Windows 2000 and Xp. The limitation is unified the same as DS*SYSTEM4. This program needs 20 M byte of working disk space. A laser printer with HP-GL emulation and Postscript driver is needed for drawing. Documentation and latest executable files are available from this Version 5 Page.