Introduction

The LauePt computer program is an interactive Windows app for simulating white-beam X-ray Laue patterns of general crystals. It is a small-size program but has convenient and straightforward graphic user interfaces (GUIs), with which one can quickly simulate a complicated Laue pattern only with a few mouse clicks. Therefore, it can be used even by non-specialists with little crystallography knowledge. The simulated Laue patterns can be directly compared with real patterns recorded by CCD cameras or X-ray films. LauePt does not have a procedure to process raw Laue images into 2D maps of diffraction spot positions. Instead, it allows the user to import a recorded Laue image as the background, and the simulated pattern is plotted directly on top of the background image for interactive visual comparison. This feature dramatically reduces the complexity of Laue pattern simulation/fitting compared with other programs. LauePt has another unique advantage, the accurate calculations of intensities (including harmonics), which makes the visual comparison effects of both diffraction spot positions and intensities completely unambiguous, even for poor-quality recorded images.

The current LauePt4 is a major upgrade with implementation of three fast searching schemes to quickly fit Laue patterns taken from crystals with unknown orientations. The first scheme is a single-spot G-rotation method, which allows the user to select a single diffraction spot and rotate the crystal around this reflection to find the correct pattern and crystal orientation. The second is a two-spot looking-up method, LUT-P, that selects two diffraction spots and searches all the reflection pairs satisfying the interplanar angle of these two spots. The third is a more efficient three-spot looking-up method, LUT-T, which searches reflection triplets satisfying the three interplanar angles between three user-selected diffraction spots and performs the simulation. All the three methods have been extensively tested to be reliable and robust.

Download

Local download: LauePt4 for Windows

GitHub: https://github.com/yaafeiliu/LauePt4

LauePt4 is freely available for scientific use only. Commercial use or distribution is not allowed.
You can download the zip file and unzip it. No installation is necessary. Simply click the LauePt4.exe file to run the program. (You may create a shortcut on your desk.)

Reference

[1] V. W. Huang, Y. Liu, B. Raghothamachar and M. Dudley, Upgraded LauePt4 for rapid recognition and fitting of Laue patterns from crystals with unknown orientations, Journal of Applied Crystallography, 56 (5), 1610-1615 (2023).
[2] X. Huang, LauePt, a graphical-user-interface program for simulating and analyzing white-beam X-ray diffraction Laue patterns. Journal of Applied Crystallography 43 (2010), 926-928.