First-principles calculations of dielectric constants of C20C20 bulk using Wannier functions

The polarization and dielectric constants of the C20C20 bulk are evaluated from the shifting of Wannier-function centers by applying external electric fields. The observed structural anisotropy of dielectric constants is due to the different amount of the shifts of electrons in C–C bonds and CCCC bonds under the electric field. The dielectric constant becomes largest in the case of applying the electric field in parallel to the CCCC bond axis.