Optical Properties
dielectric function in micro-scale
where:
- : Change in charge density
- : Electric susceptibility
- : External potential change
- : Polarization function
- : dielectric function
- : total potential change, which is sum of changes in the external potential and induced one
INFO
the short formula is used above equations
From these equations, we obtain the following equations straightforwardly
where:
- : Coulomb potential
RPA Approxiamation:
where
- : Kohn-Sham density response function
macroscale dielectric function
without local field correction
in this case, the macroscoptic dielectric function is obtained by following way
only, component of is needed, being the low computational cost.
local field correction
in this case, all matrix element of is needed to calculate the inverse of matrix. See the Adler for the details.
relation with optical functions
- : refractive index
- : extinction coeffcient
- : reflectance