GroupTheory`

GTShells

GTShells[cluster,basis,shells]

performs a reordering in shells around the atoms in the basis.

Details and Options

For several tasks it is necessary to reorder the atoms into shells, i.e. correponding to the distance to an atom in the basis. The number of shells to take into account is given in shells. It is a list containing the number of shells to take into account for each atom of the basis.
The construction of tight-binding Hamiltonians needs the information about shells in a special form. This output will be forced by GOTbLattice. The option contains information about interactions of the atoms in the basis and the number of shells to be taken into account for the interactions.
The following options can be given:

GOPosition	"Absolute"	Shifts the origin during the construction of a cluster
GOTbLattice	{}	Provides details information for the construction of tight-binding Hamiltonians
GOVerbose	False	Controls the output of additional information

See: W. Hergert, M. Geilhufe, Group Theory in Solid State Physics and Photonics. Problem Solving with Mathematica, chapter 9.4

Examples

open allclose all

Basic Examples (1)

First load the package:

Cluster and shells will be constructed for the NaCl structure.

Options (3)

GOPosition (1)

If GOPosition is set to “Relative” the relative position to the basis atom is stored, otherwise the position which is found in the cluster construction.

GOTbLattice (1)

A Hamiltonian for the NaCl structure will be constructed. Therefore the tight-bindig form of the information about the shells has to be generated. The central atom is "Na". The interactions: "Na,Na", "Na,Cl", and "Cl,Cl" will be considered only for the nearest neighbors.

GOVerbose (1)

GOVerboseFalse surpresses the output of the printed table.