quantum-espresso/PW/sum_band.f90

747 lines
27 KiB
Fortran

!
! Copyright (C) 2001-2005 PWSCF 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 .
!
#include "f_defs.h"
!
!----------------------------------------------------------------------------
SUBROUTINE sum_band()
!----------------------------------------------------------------------------
!
! ... calculates the symmetrized charge density and sum of occupied
! ... eigenvalues.
! ... this version works also for metals (gaussian spreading technique)
!
USE kinds, ONLY : DP
USE wvfct, ONLY : gamma_only
USE cell_base, ONLY : at, bg, omega
USE ions_base, ONLY : nat, ntyp => nsp, ityp
USE ener, ONLY : eband, demet, ef, ef_up, ef_dw
USE fixed_occ, ONLY : f_inp, tfixed_occ
USE gvect, ONLY : nr1, nr2, nr3, nrx1, nrx2, nrx3, nrxx
USE gsmooth, ONLY : nls, nlsm, nr1s, nr2s, nr3s, &
nrx1s, nrx2s, nrx3s, nrxxs, doublegrid
USE klist, ONLY : lgauss, degauss, ngauss, nks, &
nkstot, wk, xk, nelec, nelup, neldw, &
two_fermi_energies
USE ktetra, ONLY : ltetra, ntetra, tetra
USE ldaU, ONLY : lda_plus_U
USE lsda_mod, ONLY : lsda, nspin, current_spin, isk
USE scf, ONLY : rho
USE symme, ONLY : nsym, s, ftau
USE io_files, ONLY : iunwfc, nwordwfc, iunigk
USE uspp, ONLY : nkb, vkb, becsum, nhtol, nhtoj, indv, okvan
USE uspp_param, ONLY : nh, tvanp, nhm
USE wavefunctions_module, ONLY : evc, psic, evc_nc, psic_nc
USE noncollin_module, ONLY : noncolin, bfield, npol
USE spin_orb, ONLY : lspinorb, domag, fcoef
USE wvfct, ONLY : nbnd, npwx, npw, igk, wg, et
USE control_flags, ONLY : wg_set
USE mp_global, ONLY : intra_image_comm, me_image, &
root_image, npool, my_pool_id
USE mp, ONLY : mp_bcast
!
IMPLICIT NONE
!
! ... local variables
!
INTEGER :: ikb, jkb, ijkb0, ih, jh, ijh, na, np
! counters on beta functions, atoms, pseudopotentials
INTEGER :: ir, is, ig, ibnd, ik
! counter on 3D r points
! counter on spin polarizations
! counter on g vectors
! counter on bands
! counter on k points
real (kind=DP) demet_up, demet_dw
!
!
CALL start_clock( 'sum_band' )
!
becsum(:,:,:) = 0.D0
rho(:,:) = 0.D0
eband = 0.D0
demet = 0.D0
!
IF ( .NOT. lgauss .AND. .NOT. ltetra .AND. .NOT. tfixed_occ ) THEN
!
! ... calculate weights for the insulator case
!
if (two_fermi_energies) then
CALL iweights( nks, wk, nbnd, nelup, et, ef_up, wg, 1, isk )
CALL iweights( nks, wk, nbnd, neldw, et, ef_dw, wg, 2, isk )
else
CALL iweights( nks, wk, nbnd, nelec, et, ef, wg, 0, isk )
end if
!
ELSE IF ( ltetra ) THEN
!
! ... calculate weights for the metallic case
!
CALL poolrecover( et, nbnd, nkstot, nks )
!
IF ( me_image == root_image ) THEN
!
IF (two_fermi_energies) THEN
CALL tweights( nkstot, nspin, nbnd, nelup, ntetra, tetra, et, &
ef_up, wg, 1, isk )
CALL tweights( nkstot, nspin, nbnd, neldw, ntetra, tetra, et, &
ef_dw, wg, 2, isk )
ELSE
CALL tweights( nkstot, nspin, nbnd, nelec, ntetra, tetra, et, &
ef, wg, 0, isk )
END IF
!
END IF
!
CALL poolscatter( nbnd, nkstot, wg, nks, wg )
!
CALL mp_bcast( ef, root_image, intra_image_comm )
!
ELSE IF ( lgauss ) THEN
!
if (two_fermi_energies) then
CALL gweights( nks, wk, nbnd, nelup, degauss, ngauss, et, ef_up, &
demet_up, wg, 1, isk)
CALL gweights( nks, wk, nbnd, neldw, degauss, ngauss, et, ef_dw, &
demet_dw, wg, 2, isk)
demet = demet_up + demet_dw
bfield(3)=(ef_up-ef_dw)*0.5d0
else
CALL gweights( nks, wk, nbnd, nelec, degauss, ngauss, et, ef, &
demet, wg, 0, isk)
end if
!
ELSE IF ( tfixed_occ ) THEN
!
IF ( npool == 1 ) THEN
!
wg = f_inp
!
ELSE
!
wg(:,1) = f_inp(:,my_pool_id+1)
wg(:,2) = f_inp(:,my_pool_id+1)
!
END IF
!
ef = - 1.0D+20
!
DO is = 1, nspin
!
DO ibnd = 1, nbnd
!
IF ( wg(ibnd,is) > 0.D0 ) ef = MAX( ef, et(ibnd,is) )
!
END DO
!
END DO
!
END IF
!
wg_set = .TRUE.
!
! ... Needed for LDA+U
!
IF ( lda_plus_u ) CALL new_ns()
!
! ... specific routines are called to sum for each k point the contribution
! ... of the wavefunctions to the charge
!
IF ( gamma_only ) THEN
!
CALL sum_band_gamma()
!
ELSE
!
CALL sum_band_k()
!
END IF
!
! ... If a double grid is used, interpolate onto the fine grid
!
IF ( doublegrid ) THEN
!
DO is = 1, nspin
!
CALL interpolate( rho(1,is), rho(1,is), 1 )
!
END DO
!
END IF
!
! ... Here we add the Ultrasoft contribution to the charge
!
IF ( okvan ) CALL addusdens()
!
IF ( noncolin .AND. .NOT. domag ) rho(:,2:4)=0.D0
!
CALL poolreduce( 1, eband )
CALL poolreduce( 1, demet )
!
! ... symmetrization of the charge density (and local magnetization)
!
#if defined (__PARA)
!
! ... reduce charge density across pools
!
CALL poolreduce( nspin * nrxx, rho )
!
IF ( noncolin ) THEN
!
CALL psymrho( rho(1,1), nrx1, nrx2, nrx3, nr1, nr2, nr3, nsym, s, ftau )
!
IF ( domag ) &
CALL psymrho_mag( rho(1,2), nrx1, nrx2, nrx3, &
nr1, nr2, nr3, nsym, s, ftau, bg, at )
!
ELSE
!
DO is = 1, nspin
!
CALL psymrho( rho(1,is), nrx1, nrx2, nrx3, &
nr1, nr2, nr3, nsym, s, ftau )
!
END DO
!
END IF
!
#else
!
IF ( noncolin ) THEN
!
CALL symrho( rho(1,1), nrx1, nrx2, nrx3, nr1, nr2, nr3, nsym, s, ftau )
!
IF ( domag ) &
CALL symrho_mag( rho(1,2), nrx1, nrx2, nrx3, &
nr1, nr2, nr3, nsym, s, ftau, bg, at )
!
ELSE
!
DO is = 1, nspin
!
CALL symrho( rho(1,is), nrx1, nrx2, nrx3, nr1, nr2, nr3, nsym, s, ftau )
!
END DO
!
END IF
!
#endif
!
CALL stop_clock( 'sum_band' )
!
RETURN
!
CONTAINS
!
! ... internal procedures
!
!-----------------------------------------------------------------------
SUBROUTINE sum_band_gamma()
!-----------------------------------------------------------------------
!
! ... gamma version
!
IMPLICIT NONE
!
! ... local variables
!
REAL(KIND=DP) :: w1, w2
! weights
REAL(KIND=DP), ALLOCATABLE :: becp(:,:)
! contains <beta|psi>
!
!
ALLOCATE( becp( nkb, nbnd ) )
!
! ... here we sum for each k point the contribution
! ... of the wavefunctions to the charge
!
IF ( nks > 1 ) REWIND( iunigk )
!
k_loop: DO ik = 1, nks
!
IF ( lsda ) current_spin = isk(ik)
!
IF ( nks > 1 ) THEN
!
READ( iunigk ) npw, igk
CALL davcio( evc, nwordwfc, iunwfc, ik, -1 )
!
END IF
!
IF ( nkb > 0 ) &
CALL init_us_2( npw, igk, xk(1,ik), vkb )
!
! ... here we compute the band energy: the sum of the eigenvalues
!
DO ibnd = 1, nbnd
!
! ... the sum of eband and demet is the integral for
! ... e < ef of e n(e) which reduces for degauss=0 to the sum of
! ... the eigenvalues.
!
eband = eband + et(ibnd,ik) * wg(ibnd,ik)
!
END DO
!
DO ibnd = 1, nbnd, 2
!
psic(:) = ( 0.D0, 0.D0 )
!
IF ( ibnd < nbnd ) THEN
!
! ... two ffts at the same time
!
psic(nls(igk(1:npw))) = evc(1:npw,ibnd) + &
( 0.D0, 1.D0 ) * evc(1:npw,ibnd+1)
psic(nlsm(igk(1:npw))) = CONJG( evc(1:npw,ibnd) - &
( 0.D0, 1.D0 ) * evc(1:npw,ibnd+1) )
!
ELSE
!
psic(nls(igk(1:npw))) = evc(1:npw,ibnd)
psic(nlsm(igk(1:npw))) = CONJG( evc(1:npw,ibnd) )
!
END IF
!
CALL cft3s( psic, nr1s, nr2s, nr3s, nrx1s, nrx2s, nrx3s, 2 )
!
w1 = wg(ibnd,ik) / omega
!
! ... increment the charge density ...
!
IF ( ibnd < nbnd ) THEN
!
! ... two ffts at the same time
!
w2 = wg(ibnd+1,ik) / omega
!
ELSE
!
w2 = w1
!
END IF
!
DO ir = 1, nrxxs
!
rho(ir,current_spin) = rho(ir,current_spin) + &
w1 * REAL( psic(ir) )**2 + &
w2 * AIMAG( psic(ir) )**2
!
END DO
!
END DO
!
! ... If we have a US pseudopotential we compute here the becsum term
!
IF ( .NOT. okvan ) CYCLE k_loop
!
IF ( nkb > 0 ) &
CALL ccalbec( nkb, npwx, npw, nbnd, becp, vkb, evc )
!
CALL start_clock( 'becsum' )
!
DO ibnd = 1, nbnd
!
w1 = wg(ibnd,ik)
ijkb0 = 0
!
DO np = 1, ntyp
!
IF ( tvanp(np) ) THEN
!
DO na = 1, nat
!
IF ( ityp(na) == np ) THEN
!
ijh = 1
!
DO ih = 1, nh(np)
!
ikb = ijkb0 + ih
!
becsum(ijh,na,current_spin) = &
becsum(ijh,na,current_spin) + &
w1 * becp(ikb,ibnd) * becp(ikb,ibnd)
!
ijh = ijh + 1
!
DO jh = ( ih + 1 ), nh(np)
!
jkb = ijkb0 + jh
!
becsum(ijh,na,current_spin) = &
becsum(ijh,na,current_spin) + &
w1 * 2.D0 * becp(ikb,ibnd) * becp(jkb,ibnd)
!
ijh = ijh + 1
!
END DO
!
END DO
!
ijkb0 = ijkb0 + nh(np)
!
END IF
!
END DO
!
ELSE
!
DO na = 1, nat
!
IF ( ityp(na) == np ) ijkb0 = ijkb0 + nh(np)
!
END DO
!
END IF
!
END DO
!
END DO
!
CALL stop_clock( 'becsum' )
!
END DO k_loop
!
DEALLOCATE( becp )
!
RETURN
!
END SUBROUTINE sum_band_gamma
!
!
!-----------------------------------------------------------------------
SUBROUTINE sum_band_k()
!-----------------------------------------------------------------------
!
! ... k-points version
!
IMPLICIT NONE
!
! ... local variables
!
REAL(KIND=DP) :: w1
! weights
COMPLEX(KIND=DP), ALLOCATABLE :: becp(:,:), becp_nc(:,:,:)
! contains <beta|psi>
!
COMPLEX(KIND=DP), ALLOCATABLE :: be1(:,:), be2(:,:)
!
INTEGER :: ipol, kh, kkb, is1, is2
!
IF (noncolin) THEN
ALLOCATE( becp_nc( nkb, npol, nbnd ) )
IF (lspinorb) ALLOCATE(be1(nhm,2), be2(nhm,2))
ELSE
ALLOCATE( becp( nkb, nbnd ) )
ENDIF
!
! ... here we sum for each k point the contribution
! ... of the wavefunctions to the charge
!
IF ( nks > 1 ) REWIND( iunigk )
!
k_loop: DO ik = 1, nks
!
IF ( lsda ) current_spin = isk(ik)
!
IF ( nks > 1 ) THEN
!
READ( iunigk ) npw, igk
IF (noncolin) THEN
CALL davcio( evc_nc, nwordwfc, iunwfc, ik, -1 )
ELSE
CALL davcio( evc, nwordwfc, iunwfc, ik, -1 )
ENDIF
!
END IF
!
IF ( nkb > 0 ) &
CALL init_us_2( npw, igk, xk(1,ik), vkb )
!
! ... here we compute the band energy: the sum of the eigenvalues
!
DO ibnd = 1, nbnd
!
eband = eband + et(ibnd,ik) * wg(ibnd,ik)
!
! ... the sum of eband and demet is the integral for e < ef of
! ... e n(e) which reduces for degauss=0 to the sum of the
! ... eigenvalues
w1 = wg(ibnd,ik) / omega
IF (noncolin) THEN
psic_nc = (0.D0,0.D0)
DO ipol=1,npol
DO ig = 1, npw
psic_nc(nls(igk(ig)),ipol)=evc_nc(ig,ipol,ibnd)
END DO
call cft3s (psic_nc(1,ipol), nr1s, nr2s, nr3s, nrx1s, &
nrx2s, nrx3s, 2)
END DO
w1 = wg (ibnd, ik) / omega
!
! increment the charge density ...
!
DO ipol=1,npol
DO ir = 1, nrxxs
rho (ir, 1) = rho (ir, 1) + &
w1*(DREAL(psic_nc(ir,ipol))**2+DIMAG(psic_nc(ir,ipol))**2)
END DO
END DO
!
! In this case, calculate also the three
! components of the magnetization (stored in rho(ir,2-4) )
!
IF (domag) THEN
DO ir = 1,nrxxs
rho(ir,2) = rho(ir,2) + w1*2.D0* &
(real(psic_nc(ir,1))*real(psic_nc(ir,2)) + &
DIMAG(psic_nc(ir,1))*DIMAG(psic_nc(ir,2)))
rho(ir,3) = rho(ir,3) + w1*2.D0* &
(real(psic_nc(ir,1))*DIMAG(psic_nc(ir,2)) - &
real(psic_nc(ir,2))*DIMAG(psic_nc(ir,1)))
rho(ir,4) = rho(ir,4) + w1* &
(real(psic_nc(ir,1))**2+DIMAG(psic_nc(ir,1))**2 &
-real(psic_nc(ir,2))**2-DIMAG(psic_nc(ir,2))**2)
END DO
ELSE
rho(ir,2:4)=0.d0
END IF
!
ELSE
!
psic(:) = ( 0.D0, 0.D0 )
!
psic(nls(igk(1:npw))) = evc(1:npw,ibnd)
!
CALL cft3s( psic, nr1s, nr2s, nr3s, nrx1s, nrx2s, nrx3s, 2 )
!
!
! ... increment the charge density ...
!
DO ir = 1, nrxxs
!
rho(ir,current_spin) = rho(ir,current_spin) + &
w1 * ( REAL( psic(ir) )**2 + &
AIMAG( psic(ir) )**2 )
!
END DO
!
END IF
!
END DO
!
! ... If we have a US pseudopotential we compute here the becsum term
!
IF ( .NOT. okvan ) CYCLE k_loop
!
IF (noncolin) THEN
IF ( nkb > 0 ) &
CALL ccalbec_nc( nkb, npwx, npw, npol, nbnd, &
becp_nc, vkb, evc_nc )
ELSE
IF ( nkb > 0 ) &
CALL ccalbec( nkb, npwx, npw, nbnd, becp, vkb, evc )
ENDIF
!
CALL start_clock( 'becsum' )
!
DO ibnd = 1, nbnd
!
w1 = wg(ibnd,ik)
ijkb0 = 0
!
DO np = 1, ntyp
!
IF ( tvanp(np) ) THEN
!
DO na = 1, nat
!
IF (ityp(na)==np) THEN
!
IF (lspinorb) THEN
be1=(0.d0,0.d0)
be2=(0.d0,0.d0)
DO ih = 1, nh(np)
ikb = ijkb0 + ih
DO kh = 1, nh(np)
IF ((nhtol(kh,np)==nhtol(ih,np)).AND. &
(nhtoj(kh,np)==nhtoj(ih,np)).AND. &
(indv(kh,np)==indv(ih,np))) THEN
kkb=ijkb0 + kh
DO is1=1,2
DO is2=1,2
be1(ih,is1)=be1(ih,is1)+ &
fcoef(ih,kh,is1,is2,np)* &
becp_nc(kkb,is2,ibnd)
be2(ih,is1)=be2(ih,is1)+ &
fcoef(kh,ih,is2,is1,np)* &
CONJG(becp_nc(kkb,is2,ibnd))
END DO
END DO
END IF
END DO
END DO
END IF
ijh = 1
!
DO ih = 1, nh(np)
!
ikb = ijkb0 + ih
!
IF (noncolin) THEN
!
IF (lspinorb) THEN
becsum(ijh,na,1)=becsum(ijh,na,1)+ w1*&
(be1(ih,1)*be2(ih,1)+ be1(ih,2)*be2(ih,2))
IF (domag) THEN
becsum(ijh,na,2)=becsum(ijh,na,2)+ w1*&
(be1(ih,2)*be2(ih,1)+ be1(ih,1)*be2(ih,2))
becsum(ijh,na,3)=becsum(ijh,na,3)+ &
w1*(0.d0,-1.d0)* &
(be1(ih,2)*be2(ih,1)-be1(ih,1)*be2(ih,2))
becsum(ijh,na,4)=becsum(ijh,na,4)+ w1* &
(be1(ih,1)*be2(ih,1)-be1(ih,2)*be2(ih,2))
ENDIF
ELSE
becsum(ijh,na,1) = becsum(ijh,na,1) &
+ w1*( CONJG(becp_nc(ikb,1,ibnd)) &
*becp_nc(ikb,1,ibnd) &
+ CONJG(becp_nc(ikb,2,ibnd)) &
*becp_nc(ikb,2,ibnd) )
IF (domag) THEN
becsum(ijh,na,2)=becsum(ijh,na,2) &
+ w1*(CONJG(becp_nc(ikb,2,ibnd)) &
*becp_nc(ikb,1,ibnd) &
+ CONJG(becp_nc(ikb,1,ibnd)) &
*becp_nc(ikb,2,ibnd) )
becsum(ijh,na,3)=becsum(ijh,na,3) &
+ w1*2.d0 &
*DIMAG(CONJG(becp_nc(ikb,1,ibnd))* &
becp_nc(ikb,2,ibnd) )
becsum(ijh,na,4) = becsum(ijh,na,4) &
+ w1*( CONJG(becp_nc(ikb,1,ibnd)) &
*becp_nc(ikb,1,ibnd) &
- CONJG(becp_nc(ikb,2,ibnd)) &
*becp_nc(ikb,2,ibnd) )
END IF
END IF
ELSE
becsum(ijh,na,current_spin) = &
becsum(ijh,na,current_spin) + &
w1 * REAL( CONJG( becp(ikb,ibnd) ) * &
becp(ikb,ibnd) )
END IF
!
ijh = ijh + 1
!
DO jh = ( ih + 1 ), nh(np)
!
jkb = ijkb0 + jh
!
IF (noncolin) THEN
IF (lspinorb) THEN
becsum(ijh,na,1)=becsum(ijh,na,1)+ w1*( &
(be1(jh,1)*be2(ih,1)+be1(jh,2)*be2(ih,2))+ &
(be1(ih,1)*be2(jh,1)+be1(ih,2)*be2(jh,2)))
IF (domag) THEN
becsum(ijh,na,2)=becsum(ijh,na,2)+w1*( &
(be1(jh,2)*be2(ih,1)+be1(jh,1)*be2(ih,2))+&
(be1(ih,2)*be2(jh,1)+be1(ih,1)*be2(jh,2)))
becsum(ijh,na,3)=becsum(ijh,na,3)+ &
w1*(0.d0,-1.d0)*((be1(jh,2)*&
be2(ih,1)-be1(jh,1)*be2(ih,2))+ &
(be1(ih,2)*be2(jh,1)-be1(ih,1)*&
be2(jh,2)) )
becsum(ijh,na,4)=becsum(ijh,na,4)+ &
w1*((be1(jh,1)*be2(ih,1)- &
be1(jh,2)*be2(ih,2))+ &
(be1(ih,1)*be2(jh,1)- &
be1(ih,2)*be2(jh,2)) )
END IF
ELSE
becsum(ijh,na,1)= becsum(ijh,na,1)+ &
w1*2.d0* &
REAL(CONJG(becp_nc(ikb,1,ibnd))* &
becp_nc(jkb,1,ibnd) + &
CONJG(becp_nc(ikb,2,ibnd))* &
becp_nc(jkb,2,ibnd) )
IF (domag) THEN
becsum(ijh,na,2)=becsum(ijh,na,2)+ &
w1*2.d0* &
REAL(CONJG(becp_nc(ikb,2,ibnd))* &
becp_nc(jkb,1,ibnd) + &
CONJG(becp_nc(ikb,1,ibnd))* &
becp_nc(jkb,2,ibnd) )
becsum(ijh,na,3)=becsum(ijh,na,3)+ &
w1*2.d0* &
DIMAG(CONJG(becp_nc(ikb,1,ibnd))* &
becp_nc(jkb,2,ibnd) + &
CONJG(becp_nc(ikb,1,ibnd))* &
becp_nc(jkb,2,ibnd) )
becsum(ijh,na,4)=becsum(ijh,na,4)+ &
w1*2.d0* &
REAL(CONJG(becp_nc(ikb,1,ibnd))* &
becp_nc(jkb,1,ibnd) - &
CONJG(becp_nc(ikb,2,ibnd))* &
becp_nc(jkb,2,ibnd) )
END IF
END IF
ELSE
!
becsum(ijh,na,current_spin) = &
becsum(ijh,na,current_spin) + w1 * 2.D0 * &
REAL( CONJG( becp(ikb,ibnd) ) * &
becp(jkb,ibnd) )
ENDIF
!
ijh = ijh + 1
!
END DO
!
END DO
!
ijkb0 = ijkb0 + nh(np)
!
END IF
!
END DO
!
ELSE
!
DO na = 1, nat
!
IF ( ityp(na) == np ) ijkb0 = ijkb0 + nh(np)
!
END DO
!
END IF
!
END DO
!
END DO
!
CALL stop_clock( 'becsum' )
!
END DO k_loop
!
IF (noncolin) THEN
DEALLOCATE( becp_nc )
IF (lspinorb) DEALLOCATE(be1, be2)
ELSE
DEALLOCATE( becp )
ENDIF
!
RETURN
!
END SUBROUTINE sum_band_k
!
END SUBROUTINE sum_band