IFC calculation in polar materials

[rfhari]

Hi, I have a question regarding including "--polar" tag for polar materials like GaN/AlN.

I was following this workflow on extracting second and third-order force constants for GaN. It mentions about including "--polar" tag to account for the long-range electrostatics.

I'm a bit unsure about how the non-analytical correction term is implemented in the TDEP package. Based on my understanding, the correction terms are included as a correction factor at the Gamma point in the dynamical matrix calculation (and lattice thermal conductivity) to account for the residual long-range effects missed out due to real-space cutoffs used in force constants. However, I'm not entirely sure how they come into effect while calculating the force constant itself.

Can you please help clarifying this?