LEEDpat4 web ad

LEEDpat4
(LEED pattern analyzer)

Version 4.2 (December 2015)


PC-based software tool to visualize and analyze LEED patterns of substrates and overlayers


CONTENTS OF THIS PAGE:



PROGRAM CAPABILITIES

LEEDpat is designed to help interpret experimentally observed LEED spot patterns for well-ordered surfaces especially in the presence of superlattices. In particular, LEEDpat allows one to tell which 2D surface lattices are compatible with an observed LEED pattern. Rotational domains and glide plane extinction of spots are taken into account (the latter at normal incidence only). For further details see LEEDpat manual

LEEDpat also provides extensive 2D symmetry information, showing all rotational, mirror and glide symmetries that are compatible with the observed pattern. This allows the user to narrow down possible structural models of the surface and to propose atomic positions in the actual structure. However, LEEDpat does not itself predict structural models or atomic coordinates: it does not calculate spot intensities, which would be needed to determine atomic positions.

The user can select any basic 2D substrate lattice (square, hexagonal, rectangular, or oblique), including any possible symmetries (i.e. any of the 17 two-dimensional space groups). The user can also specify any commensurate or incommensurate superlattice, again with any possible symmetries (commensurate only). LEEDpat then draws both a real-space lattice and a LEED pattern (representing reciprocal lattices), including the option of symmetry-related domain orientations (of equal weight). The user can thus, by trial and error, find the pattern that best matches the experiment.

Version 4 of LEEDpat includes many improvements and new features. In particular, it offers now The present version 4.2 of LEEDpat has some general limitations (which cannot be overcome) and simplifications (which may be fixed in later versions): Despite these limitations, LEEDpat can simulate a large fraction of observed patterns, and thus should be useful in most cases.

Return to top of this form

SOFTWARE RUNS ON THE FOLLOWING HARDWARE:

Return to top of this form

DOWNLOADING

Latest update version as of January 13, 2016

Start downloading the LEEDpat package in a single file (3 MB) by identifying yourself with your name and email address.
(This information will be used ONLY for announcements of major updates and not passed on to others. Obviously fake or obscene addresses will not be accepted.)

Your name

Your e-mail address

To complete downloading click the download button.

     

After having downloaded file LEEDpat42Install.exe you may install LEEDpat on your PC. For instructions see INSTALLATION on this page. You may return to this page from the download page by clicking the "RETURN TO LEEDpat homepage" button in the download page.

Return to top of this form

INSTALLATION AND RUNNING:

The INSTALLATION of LEEDpat is straightforward and consists in the most general case of four steps. (Note that your browser may have download switches set such that one or more of the following steps are performed automatically.)
  1. Unpack all files by running the downloaded file LEEDpat42Install.exe. (Your browser may use a default directory for file downloading. Then you may have to look for this file in your PC with Window's find option.) This will ask you for the name of an installation subdirectory, e.g. c:\TEMP (or any other temporary directory, which must be different from the permanent directory where you wish LEEDpat to be installed). This subdirectory contains all system installation files. Note that the installation directory cannot be used as the final LEEDpat directory, see step 2.

  2. Install all LEEDpat files by running Setup.exe inside the installation subdirectory (see step 1). This will ask you for the name of the final LEEDpat subdirectory, e.g. c:\Program files\LEEDpat42 (or any other permanent directory), to contain the LEEDpat package.

  3. Set a LEEDpat icon on the desktop. Go to directory INSTALL and create a shortcut of LEEDpat42.exe (open directory INSTALL with your file explorer, right-click file LEEDpat42.exe, choose "Create Shortcut" from the menu which creates a shortcut file) and drag the shortcut file onto the desktop.

  4. Clean up by removing all installation files from directory TEMP. You may leave the original download file LEEDpat42Install.exe for backup purposes.
NOTE that starting with version 4.2 of LEEDpat the new html based help option (default for MS Windows 7 and later) is available by default but the traditional Windows help can still be used as an option. Microsoft, in its wisdom, has discontinued providing the traditional Windows help engine (WinHlp32.exe) with MS Windows 7 and later by default. The absence of WinHlp32.exe in your PC will make the old LEEDpat help option unavailable. However, WinHlp32.exe can be downloaded from Microsoft and installed in your Windows PC free of charge. This will enable the traditional LEEDpat help option if needed.

NOTE that Microsoft does not include the Visual Basic 6 runtime environment (required by LEEDpat) in its Windows 8, 8.1 versions by default. However, the VB6 runtime environment can be downloaded from Microsoft and installed in your Windows PC free of charge. This will enable LEEDpat to run also under Windows 8, 8.1.

You RUN LEEDpat Return to top of this form

HOW TO CONTACT THE AUTHORS

We are open to any questions and suggestions concerning the LEEDpat software. You can contact the authors using addresses

Return to top of this form