Last Modified 17 December 1999

The ``Static'' Tight-Binding Program: Example XIV

Note: This example uses a Perl script and other auxillary files. For more information about obtaining and installing these files, see the Scripts and Auxillary Programs page.

skingen is a script written in Perl, a high-level scripting language. skingen is designed to:

• Automate the construction of the SKIN (Slater-Koster INput) file for the static program, and
• ease the selection of space-group and k-point meshes for certain common structures.

One of the most difficult problems in setting up a calculation using the static program is the construction of the main input file, SKIN. The format of this file is the ``culmination'' of years of development of the static program. The user may not be aware of some options available through the SKIN file, and some options may be so obscure as to be completely useless to everyone except the code developer.

skingen was developed to get around these problems. It provides a SKIN file for most common calculations. This file can then be used as a template which can then be modified to include some of the more obscure options.

skingen divides a problem into several parts, prompting you to

1. Choose the type calculation, i.e., the mode.
2. Determine the ultimate accuracy of the calculation, using Fermi smearing with or without Gillan's extrapolation.
3. Choose the Tight-binding parametrization file.
4. Set up the initial structure, including:
   1. Labels
   2. Lattice Type
   3. Lattice parameters
   4. Strain Type
   5. Search parameters
   6. Number of atoms
   7. Atomic types and positions
   8. Space group and k-point mesh
5. Set up new lattice parameters and positions for the next structure, allowing for easy entry of default values.

Note that:

• in its current form skingen only allows one lattice/strain type and one k-point mesh per SKIN file. You can have as many different sets of lattice parameters and atomic positions as you want, so long as you don't change the lattice type or the k-point mesh.
• skingen designates some values as ``default.'' If you see a prompt which includes a default value, pressing the <Enter> key will enter that value into the SKIN file.
• at many prompts skingen provides context-sensitive help. Enter ``h'' to access this help.
• I am not an expert Perl programmer, nor have I anticipated all possible useful features in skingen. Suggestions for improvements to this code will be welcome, especially if they include the source code modifications. Send suggestions to mehl@dave.nrl.navy.mil.

To illustrate the workings of skingen, we rework some of the other examples in this manual:

1. The first half of Example I, where we look at the total energy of fcc Palladium.
2. The energy of a small cubic cluster of copper atoms, as found in Example XI.

Look at other examples.

Get other parameters from the Tight-binding periodic table.

Return to the static Reference Manual.