EPW Forum

Dear all,
Recently, I am studying some CDW-related materials. When calculated the FS nesting related properties, I found that the nesting functions always has a larger value at Gamma points. As far as I know, the nesting function is always calculated through the imaginary part of electron susceptibility (the Lindhard function only determine the stability of the system). My question is Why the imaginary part of electron susceptibility always has maximum at Gamma point?


Best wishes,
jgsi

"The imaginary part of the electron susceptibility always shows the maximum around the zero point, which is due to intraband contributions from a weakly dispersing band and is irrelevant for the nesting."
Ref:Phys. Rev. B 101, 235405 (2020) & Phys. Rev. B 74, 155114 (2006).