mirror of https://gitlab.com/QEF/q-e.git
79 lines
2.0 KiB
Fortran
79 lines
2.0 KiB
Fortran
!
|
|
! Copyright (C) 2001-2007 Quantum-Espresso group
|
|
! 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 drhoc (ngl, gl, omega, tpiba2, mesh, r, rab, rhoc, rhocg)
|
|
!-----------------------------------------------------------------------
|
|
!
|
|
#include "f_defs.h"
|
|
USE kinds
|
|
USE constants, ONLY : pi, fpi
|
|
implicit none
|
|
!
|
|
! first the dummy variables
|
|
!
|
|
integer :: ngl, mesh
|
|
! input: the number of g shell
|
|
! input: the number of radial mesh points
|
|
|
|
real(DP) :: gl (ngl), r (mesh), rab (mesh), rhoc (mesh), omega, &
|
|
tpiba2, rhocg (ngl)
|
|
! input: the number of G shells
|
|
! input: the radial mesh
|
|
! input: the derivative of the radial mesh
|
|
! input: the radial core charge
|
|
! input: the volume of the unit cell
|
|
! input: 2 times pi / alat
|
|
! output: the fourier transform of the core charge
|
|
!
|
|
! here the local variables
|
|
!
|
|
real(DP) :: gx, g2a, rhocg1
|
|
! the modulus of g for a given shell
|
|
! the argument of the exponential
|
|
! the fourier transform
|
|
real(DP), allocatable :: aux (:)
|
|
! auxiliary memory for integration
|
|
|
|
integer :: ir, igl, igl0
|
|
! counter on radial mesh points
|
|
! counter on g shells
|
|
! lower limit for loop on ngl
|
|
|
|
allocate (aux( mesh))
|
|
!
|
|
! G=0 term
|
|
!
|
|
if (gl (1) < 1.0d-8) then
|
|
do ir = 1, mesh
|
|
aux (ir) = r (ir) **2 * rhoc (ir)
|
|
enddo
|
|
call simpson (mesh, aux, rab, rhocg1)
|
|
rhocg (1) = fpi * rhocg1 / omega
|
|
igl0 = 2
|
|
else
|
|
igl0 = 1
|
|
endif
|
|
!
|
|
! G <> 0 term
|
|
!
|
|
do igl = igl0, ngl
|
|
gx = sqrt (gl (igl) * tpiba2)
|
|
call sph_bes (mesh, r, gx, 0, aux)
|
|
do ir = 1, mesh
|
|
aux (ir) = r (ir) **2 * rhoc (ir) * aux (ir)
|
|
enddo
|
|
call simpson (mesh, aux, rab, rhocg1)
|
|
rhocg (igl) = fpi * rhocg1 / omega
|
|
enddo
|
|
deallocate(aux)
|
|
!
|
|
return
|
|
end subroutine drhoc
|
|
|