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Produced by ex-professor Okuyama

1. What is WinLALS?

WinLALS is a LALS program which can run on Microsoft Window's PCs ( Windows 98 / NT4.0 / 2000 / XP ). WinLALS was coded with Fortran 90 by Dr. Kenji Okada [1] based on the latest Purdue version, LALS2000 [2].

Like LALS2000, the user can choose either trigonometric or Bessel functions to calculate structure factors. However, there is no need to compile the program each time like in the previous version. Also, many amendments were made. These are changing input/output assignments, expanding most array sizes, and the update files with all parameters at each cycle.

2. What is LALS program?

Linked-Atom Least-Squares (LALS) program is a program for building molecular and crystal structures of helical polymers and refining them to fit X-ray fiber diffraction data. Fiber diffraction data from polymers are sufficiently different in kind and quantity from single crystal data. Therefore, to warrant analyses, in the refinement of competing molecular models, torsion angles (and sometimes bond angles) are the explicit variables rather than atomic coordinates. A consequent linked-atom least-squares analytical scheme evolved at the Arnott's laboratories at King's College London [3] and Purdue University [4]. WinLALS [1] has evolved from the latest version, Purdue LALS2000.

3. How to get WinLALS?

(1) To download WinLALS click WinLALS*****E.zip (520K, Ver. 1.115E).

(2) To unzip WinLALS*****E.zip, double click the file in your PC.

(3) It contains following files (2.3M )

AAEWinLALSVers.txt : WinLALS release notes

WinLALS.exe : Executable WinLALS

WinLALS.dat : Example of input data

WinLALS.pnc : Example of update file

WinLALSUsersGuide.doc : User's Guide (61 pages)

WinLALS.prn : Example of output file

and others

4. References

[1] K. Okada, K. Noguchi, K. Okuyama and S. Arnott, WinLALS for a Linked-Atom Least-Squares Refinement Program for Helical Polymers on Windows PCs, Computational Biology and Chemistry, 27, 265-285, 2003.

[2] R. Chandrasekaran, LALS User's Manual, Whistler Center for Carbohydrate Research, Purdue University, West Lafayette, IN 47907, USA, 2000.

[3] S. Arnott and A. J. Wonacott, The Refinement of the Crystal and Molecular Structures of Polymer using X-ray Data and Streochemical Constraints, Polymer, 7, 157-166, 1966.

[4] P. J. C. Smith and S. Arnott, A Linked-Atom Least-Squares Reciprocal-Space Refinement System Incorporating Streochemical Restraints to Supplement Sparse Diffraction Data, Acta Cryst., A34, 3-11, 1978.

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