Dear developers and users,
I am reaching out to seek assistance in reproducing the results presented in a paper titled "Theory of atomic-scale dielectric permittivity at insulator interfaces"
https://journals.aps.org/prb/abstract/10.1103/PhysRevB.71.144104.
I am particularly interested in the calculation of the local dielectric constant. For ionic part, the class 'BornEffectiveCharge' can return values for individual atoms, render the calculation of local dielectric constant feasible. However I can't specify which orbitals to be included in OpticalSpectrum class for calculation of electronic dielectric constant, so I wonder if I can use the derivative functions from Class 'BlochState' to calculate the momentum of individual orbital and thus the local dielectric constant. Could you please provide guidance on whether this approach is viable? Additionally, if there exists a more efficient method for performing the calculations, I would greatly appreciate your insights.
Thank you for your time.
Best regards,
Sukhito Teh