quantum-espresso/PWCOND/form_zk.f90

30 lines
749 B
Fortran

!
! Copyright (C) 2003 A. Smogunov
! This file is distributed under the terms of the
! GNU General Public License. See the file `License'
! in the root directory of the present distribution,
! or http://www.gnu.org/copyleft/gpl.txt .
!
subroutine form_zk(n2d, nrzp, zkr, zk, e, tpiba)
!
! Just to construct complex zk=sqrt(e-E_n) for energy e
! from eigenvalues E_n found for some initial energy
!
USE kinds, only : DP
implicit none
integer :: nrzp, n2d, n, k
real(kind=DP) :: zkr(n2d,nrzp), e, ed, tpiba
real(kind=DP), parameter :: eps=1.d-4
complex(kind=DP) :: zk(n2d,nrzp)
do k=1, nrzp
do n=1, n2d
ed = e-zkr(n,k)
zk(n,k)=SQRT(CMPLX(ed))/tpiba
enddo
enddo
return
end subroutine form_zk