Département de Physique
Physics Department

Sous-routines disponibles
Available subroutines

1. Brillouin-zone integration by linear tetrahedron method

SETK** routines generate sampling k-points and construct a tetrahedral partition of an irreductible polyhedron in k-space, for performing Brillouin-zone integration over this polyhedron using the linear tetrahedron method. The tetrahedra whose corners are at the nodes of a regular mesh of points fill up exactly the irreductible volume. The basic input to each SETK** routine consists in direct- space lattice parameters, or primitive translations, and so-called discretization parameters used to construct the k-mesh. On output, the SETK** routines return the number of k-points, the number of tetrahedra, the cartesian x, y, z components of the k-points and the corresponding sampling weigths and a table defining the tetrahedra (list of corner points and the volumes of the tetrahedra).

It is assumed that the cartesian coordinate system is as follows :
- Triclinic, Monoclinic and R-Trigonal systems : x,y,z along three arbitrary orthogonal directions
- P-Trigonal and Hexagonal systems : z along the three- or sixfold axis "c", x and y along two arbitrary orthogonal directions in the basal (a,b) plane
- Orthorhombic, Tetragonal and Cubic systems : x,y,z along the three orthogonal "a", "b" and "c" axes, respectively.

2. Density of states

The three following routines compute the density of states and the integrated density of states, the partial density of states of a crystal or the density of states of a superlattice.

• DOSTET computes a crystal density of states and integrated density of states by the analytical tetrahedron method.
  The routine uses outputs from the SETK** routines, and band structure data provided by the user.

• PDSTET computes partial densities of states and number of states in a crystal using the analytical tetrahedron method.
  The routine uses outputs from the SETK** routines, and band structure data provided by the user.

• SUPDOS computes the density of states of a superlattice, or any other systems with cylindrical brillouin zone.

3. Crystal Green's functions The two following routines evaluate a crystal Green's function.

• TETINE evaluates a crystal Green's function on the real axis.
  Uses the band structure data provided by the user and the Brillouin zone tetrahedral partitioning obtained from the SETK** routines.
• TETINZ evaluates a crystal Green's function in the complex energy plane. Uses the band structure data provided by the user and the Brillouin zone tetrahedral partitioning obtained from the SETK** routines.