GroupTheory`
GroupTheory`

GTVibSetParameters

GTVibSetParameters[dynamical matrix,spring constants,masses]

substitutes spring constants and masses in a dynamical matrix.

Details and Options

  • The dynamical matrix to calculate phonon spectra in a central force approximation for solids can be generated either from a tight-binding -Hamiltonian, or from the potential and force constant matrix.
  • At the end the model depends on spring constants and masses. GTVibSetParameters will substitute the corresponding parameters by actual values.
  • The following options can be given:
  • GOTbBasis 0Supress superscripts with element names.
  • See: W. Hergert, M. Geilhufe, Group Theory in Solid State Physics and Photonics. Problem Solving with Mathematica, chapter 13.2.1.

Examples

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Basic Examples  (1)

First load the package:

Read the dynamical matrix for the fcc structure.

Set the parameters in the dynamical matrix.

Calculate the phonon spectrum.

Options  (1)

GOTbBasis  (1)

Note, this example is a formal one using the a dynamical matrix constructed from the p-Hamiltonian of GaAs. It has to be checked if such a way is correct for two atoms per cell. Thius, the example here is more a formal one.

A dynamical matrix is constructed for GaAs. The matrix is read from file.

All the parameters will be substituted by actual parameters. (The parameters do not correspond to GaAs!)