Vibration modes and phonons¶
For background, see the excellent slide presentation by Andrei Postnikov.
In this set of exercises we will use the method of finite-differences implemented in Siesta to compute force constants in real space. We will explore the cases of a molecule and of a crystal. In the latter case we will focus on the need of a supercell to represent the real-space force constants.
We will also try the visualization tools available.