GroupTheory`
GroupTheory`

GTVibTbToPhonon

GTVibTbToPhonon[p-Hamiltonian, shells]

transforms a tight-binding p-Hamiltonian in a dynamical matrix, taking into account shells.

Details and Options

  • The dynamical matrix to calculate phonon spectra for solids in a central force model can be generated starting from a tight-binding p-Hamiltonian.
  • The hopping parameters (ppπ) have to be set to zero. The elements (ppσ) have to be substituted by the spring constants and the masses. The command performs this transformation.
  • The on-site elements in the dynamical matrix are not independent like in the tight-binding Hamiltonian, but have to be calculated in dependence on the spring constants and masses.
  • The following options can be given:
  • GOTbBasis 0Supresses superscripts with element names
    GOVerbose TrueControls the output of additional information
  • See: W. Hergert, M. Geilhufe, Group Theory in Solid State Physics and Photonics. Problem Solving with Mathematica, chapter 13.2.2
  • See for the idea: R.M. Martin, Electronic Structure - Basic Theory and Practical Methods, Cambridge University Press 2004, p. 404

Examples

open allclose all

Basic Examples  (1)

First load the package:

Set the directory to read data.

Read p-Hamiltonian for fcc structure from file.

The p-Hamiltonian is given up to next-nearest neighbor interactions. The interaction in the dynamical matrix is restricted to nearest neighbor interactions.

Options  (2)

GOTbBasis  (1)

The tight-binding p-Hamiltonian is constructed for GaAs.

Use up to next-nearest neighbours for all interactions.

GOVerbose  (1)

Suppress the additional information during the construction of the dynamical matrix.