A program to calculate phonons using the small displacement method (PHON software)

Dario Alfè

Department of Earth Sciences and Department of Physics and Astronomy, Thomas Young Centre@UCL and London Centre for Nanotechnology University College London, Gower street, WC1E 6BT, London, U.K.

21/09/2010

Abstract:

The program PHON calculates force constant matrices and phonon frequencies in crystals. From the frequencies it also calculates various thermodynamic quantities, like the Helmholtz free energy, the entropy, the specific heat and the internal energy of the harmonic crystal. The procedure is based on the small displacement method, and can be used in combination with any program capable to calculate forces on the atoms of the crystal.

• Program summary
• Theoretical overview
  • Phonon frequencies
  • Calculation of the force constant matrix
• Description of the program and input/output files
  • Super-cell generation
  • Phonon dispersions
  • Density of states and thermodynamic quantities
    • Partial density of states
  • Translational invariance
  • Graphical representation of phonons at 
  • Input variables and Input/Output files
• Test case
• Bibliography

Phonon tutorial
Interface to VASP
Interface to WIEN2K
Interface to PWSCF