Hi,

I'm interested on whether it's possible to calculate the dielectric constant tensor of a crystal based on Gaussian PBC. It seems that you can calculate the polarizability tensor based on frequency results, but I don't know whether it would be valid to use Clausius Mossotti equation to derive the dielectric constant tensor elements from polarizability tensor elements.

Some contact told me that there is a difference between the electronic polarizability and the reorientational polarizability, but I don't get to understand what exactly is this difference nor what are the defining equations of these two polarizabilities.

To summarize, my question is: can we compute dielectric permittivity tensor elements one by one from polarizability tensor elements through Clausius Mossotti equation?

Example:

α_xx = (3/4πN)/[(ε_xx – 1)/(ε_xx – 2)]

is this calculation valid?

All the best!