The static code has three required and two optional input files. The required files are

• SKIN (Slater-Koster INput)
  
  The SKIN file is the basic input for the static program. It gives the pointers to the tight-binding parametrization file, the space group file, the optional k-point file. It also has the input for each structure to be studied, including primitive vectors, including possible strains of the unit cell and the atomic positions. Rather than explain the components of these files, we refer the user to the appropriate parts of the examples.
  
  Starting with version 1.10, we provide a Perl-script SKIN file generator, skingen, which generates SKIN files for a wide class of problems.
  
  
• Parameter File
  
  The tight-binding parameter file. This may be obtained from the Tight-Binding Parameters Database, if a file for the system of interest is available. Contact the authors (Privacy Advisory) to see about the development of parametrizations for elements or compounds which have yet to be determined. Given the possible number of compounds available, this has to be a process driven by the interests of our users and/or our own research interests. The relative or absolute location of the parameter file must be entered in the appropriate location in the SKIN file.
  
  
• Space Group File
  
  The space group file. Space group files for many crystal structures are collected in the Crystal Lattice Structures database. Others can be constructed from the International Tables for Crystallography according to the space group construction rules. If you have no idea of the symmetry, or for calculations involving an isolated cluster of atoms, you can use this identity+inversion space group file, which contains only the identity operation and the inversion operator. The inversion operator is allowed because the eigenvalues of a Hamiltonian always obey time-reversal symmetry, that is, eig_n(-k) = eig_n(k) for every state eig_n at any wave-vector k.
  
  The purpose of the space group file is to reduce the number of k-points needed in the calculation by exploiting the symmetry of the crystal. Thus, for example, in an isolated cluster, where the calculation need be done for only one k-point, you need use only the identity space group file
  
  
• k-point File (optional)
  
  The first optional file is the k-point mesh file. K-point information is mandatory, but it can be read in as part of the SKIN file, as in Example 2, or, if desired, the k-points can be read from an external file, as in, e.g., Example 1 or Example 3. Note that for an isolated cluster you may use this single k-point file.
  
  
• TWEAKS file (optional)
  
  If it exists, the TWEAKS file tells the program to print certain diagnostic information during execution. Typically the information is printed in the SKOUT file.
  
  The TWEAKS file contains several lines of input. Each line is either a command or a number. The current commands are:
  
  
  1. PRINT_PARAMETERS: if this line is present, the Slater-Koster onsite, hopping, and overlap parameters are printed in SKOUT.
     
     
  2. PRINT_DERIVATIVE_PAR: like the above, but the derivative of these parameters with respect to volume is printed. Useful only when the pressure is computed, e.g., in Mode 2 or Mode 4 calculations.
     
     
  3. PRINT_MATRIX: if present, the next line is read. If it is an integer, i, then non-zero values of the Hamiltonian and Overlap matrices are printed in SKOUT.
     
     
  4. PRINT_PROGRESS: if set, the program prints a line to standard output (not SKOUT) every time it starts the calculation of the eigenvalues of a new k-point.
     
     
  5. PRINT_DIMENSIONS: if present, prints the dimensions set in the P[1,2,3] files to SKOUT. This is useful if you want to see if a specific executable can handle an new problem, or if you will have to redimension and recompile the code.
     
     

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Current URL: http://cst-www.nrl.navy.mil/bind/static/input_files.html