Shortrange matrixelement
Posted: Mon Dec 16, 2019 12:19 am
Hi,
When calculating the shortrange electron-phonon matrix element, in the rotate_epmat.f90 in the subroutine rgd_blk_epw, the longrange part is first substracted from the total matrix element and if the shortrange tag is set to true, the magnitude of the longrange part is substracted once more.
epmat = epmat + facq*zaq*uq*bmat (where the signe is -1 i.e. longrange vertex is substracted)
&
if (shortrange) then
epmat = SQRT(epmat*conj(epmat) - epmatl*conj(epmatl))
end if
I donot understand why the longrange matrix element is substracted twice?
It will be really helpful, if someone can comment on this formulation.
When calculating the shortrange electron-phonon matrix element, in the rotate_epmat.f90 in the subroutine rgd_blk_epw, the longrange part is first substracted from the total matrix element and if the shortrange tag is set to true, the magnitude of the longrange part is substracted once more.
epmat = epmat + facq*zaq*uq*bmat (where the signe is -1 i.e. longrange vertex is substracted)
&
if (shortrange) then
epmat = SQRT(epmat*conj(epmat) - epmatl*conj(epmatl))
end if
I donot understand why the longrange matrix element is substracted twice?
It will be really helpful, if someone can comment on this formulation.