./68_rsprc/moddiel

ABINIT/moddiel_csrb

ABINIT/moddiel_csrb [ Functions ]

NAME

 moddiel_csrb

FUNCTION

 - Compute a model real-space dielectric functions from the input density
 and dielar. Based on formula (1) of
 PRB 47, nb 15, p. 9892 (by C, S, R and B)
 - formulas for kf and qtf are from
 J. phys.: condens. matter 2 (1990) 7597-7611
 - The plasmon frequency/pulsation is from 
 Theory of the inhomogeneous electron gas (ed. Lundqvist and march) P327

 Copyright (C) 1998-2018 ABINIT group (DCA, XG, MT)
 This file is distributed under the terms of the
 GNU General Public License, see ~ABINIT/COPYING
 or http://www.gnu.org/copyleft/gpl.txt .
 For the initials of contributors, see ~ABINIT/Infos/contributors .

INPUTS

OUTPUT

 rdiemac : real space, diagonal, dielectric permittivity

SIDE EFFECTS

WARNINGS

 This is experimental code : input, ouptput, results and any other feature may vary greatly.

NOTES

PARENTS

CHILDREN

      fourdp,laplacian

SOURCE

 40 #if defined HAVE_CONFIG_H
 41 #include "config.h"
 42 #endif
 43 
 44 #include "abi_common.h"
 45 
 46 
 47 subroutine moddiel_csrb(dielar,dtset,gprimd,mpi_enreg,rdiemac,rhor_in)
 48 
 49  use defs_basis
 50  use defs_abitypes
 51  use m_profiling_abi
 52 
 53 !This section has been created automatically by the script Abilint (TD).
 54 !Do not modify the following lines by hand.
 55 #undef ABI_FUNC
 56 #define ABI_FUNC 'moddiel_csrb'
 57  use interfaces_53_ffts
 58  use interfaces_56_recipspace
 59 !End of the abilint section
 60 
 61  implicit none
 62 
 63 !Arguments -------------------------------
 64 !scalars
 65  type(MPI_type),intent(in) :: mpi_enreg
 66  type(dataset_type),intent(in) :: dtset
 67 !arrays
 68  real(dp),intent(in) :: dielar(7),gprimd(3,3),rhor_in(dtset%nfft,dtset%nspden)
 69  real(dp),intent(out) :: rdiemac(dtset%nfft,dtset%nspden)
 70 
 71 !Local variables -------------------------
 72   !real(dp) :: invqtf2(2)
 73   !real(dp) :: kf(2),wp2(2)  
 74 !scalars
 75  integer :: ifft
 76  real(dp) :: alpha
 77  complex(dpc) :: invqtf2,kf,wp2
 78 ! character(len=fnlen) :: filapp
 79 !arrays
 80  real(dp) :: g2cart(dtset%nfft),qdiemac(2,dtset%nfft,dtset%nspden)
 81  real(dp) :: rhog(2,dtset%nfft,dtset%nspden),rhor(dtset%nfft,dtset%nspden)
 82  real(dp) :: xred2(size(dtset%xred_orig,1),size(dtset%xred_orig,2))
 83  complex(dpc) :: cqdiemac(dtset%nfft,dtset%nspden)
 84  complex(dpc) :: crhog(dtset%nfft,dtset%nspden)
 85 
 86 ! *********************************************************************
 87 
 88  xred2=dtset%xred_orig(:,:,1)
 89  alpha=0.0d0
 90 !presently works only with nspden=1
 91  rhor=rhor_in
 92  call laplacian(gprimd,mpi_enreg,dtset%nfft,dtset%nspden,dtset%ngfft,dtset%paral_kgb,g2cart_out=g2cart)
 93  
 94 
 95 
 96  call fourdp(1, rhog(:,:,1), rhor(:,1),-1,mpi_enreg,dtset%nfft,dtset%ngfft,dtset%paral_kgb,0) !
 97 
 98  crhog(:,:)=cmplx(rhog(1,:,:),rhog(2,:,:))
 99 
100  cqdiemac=zero
101  do ifft=1,dtset%nfft
102 !  wp2(:)=((4.0d0*pi*rhog(:,ifft,1)))
103 !  kf(:)=((3.0d0*pi*pi*rhog(:,ifft,1))**2)**(1.0d0/6.0d0)
104 !  invqtf2(:)=(4.0d0*kf(:)/pi)**(-1)
105 !  qdiemac(:,ifft,1)=one &
106 !  & + ((dielar(3)-1)**(-1) &
107 !  & + alpha*g2cart(ifft)*invqtf2(:) &
108 !  & + g2cart(ifft)*g2cart(ifft)*4.0d0*pi*pi/(4.0d0*wp2(:)))**(-1)
109    if(crhog(ifft,1)/=(zero,zero)) then
110      wp2=((4.0d0*pi*crhog(ifft,1)))
111      kf=((3.0d0*pi*pi*crhog(ifft,1)))**(1.0d0/3.0d0)
112      invqtf2=(4.0d0*kf/pi)**(-1)
113      cqdiemac(ifft,1)=one &
114 &     + ((dielar(3)-1)**(-1) &
115 &     + alpha*g2cart(ifft)*invqtf2 &
116 &     + g2cart(ifft)*g2cart(ifft)*4.0d0*pi*pi/(4.0d0*wp2))**(-1)
117      write(212,*) cqdiemac(ifft,1),wp2,kf,invqtf2,crhog(ifft,1)
118    end if
119  end do
120  qdiemac(1,:,1)=real(cqdiemac(:,1),dp)
121  qdiemac(2,:,1)=real(aimag(cqdiemac(:,1)),dp)
122  call fourdp(1, qdiemac(:,:,1), rdiemac(:,1),1,mpi_enreg,dtset%nfft,dtset%ngfft,dtset%paral_kgb,0)
123 
124 end subroutine moddiel_csrb

TABLE OF CONTENTS

ABINIT/moddiel_csrb [ Functions ]