quantum-espresso/GWW/head/solve_head.f90

640 lines
19 KiB
Fortran

!
! Copyright (C) 2001-2021 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 solve_head
!-----------------------------------------------------------------------
!
!calculates the head and wings of the dielectric matrix
!
USE ions_base, ONLY : nat
USE io_global, ONLY : stdout, ionode,ionode_id
USE io_files, ONLY : diropn,prefix, tmp_dir
use pwcom
USE cell_base, ONLY : omega, tpiba2
USE wavefunctions, ONLY : evc
USE kinds, ONLY : DP
USE becmod, ONLY : becp,calbec
USE uspp_param, ONLY : nhm
use phcom
use units_lr, ONLY : iuwfc, lrwfc
USE wannier_gw, ONLY : n_gauss, omega_gauss, grid_type,&
nsteps_lanczos,second_grid_n,second_grid_i,&
l_scissor,scissor,len_head_block_freq, &
len_head_block_wfc, l_easy
USE control_ph, ONLY : tr2_ph
USE gvect, ONLY : ngm, ngm_g, ig_l2g, gstart, g
USE gvecs, ONLY : doublegrid
USE mp, ONLY : mp_sum, mp_barrier, mp_bcast
USE mp_world, ONLY : world_comm, mpime, nproc
USE uspp, ONLY : nkb, vkb
! USE symme, ONLY: s
USE mp_pools, ONLY : inter_pool_comm, intra_pool_comm
USE symme, only : crys_to_cart, symmatrix
USE mp_wave, ONLY : mergewf,splitwf
USE fft_base, ONLY : dfftp, dffts
USE fft_interfaces, ONLY : fwfft, invfft, fft_interpolate
USE buffers, ONLY : get_buffer
USE constants, ONLY : rytoev, fpi
use qpoint, ONLY : npwq, nksq
use control_lr, ONLY : nbnd_occ, lgamma
use uspp_init, ONLY : init_us_2
use SCF
implicit none
INTEGER, EXTERNAL :: find_free_unit
real(DP) :: thresh, anorm, averlt, dr2
! thresh: convergence threshold
! anorm : the norm of the error
! averlt: average number of iterations
! dr2 : self-consistency error
complex(DP) , allocatable :: ps (:,:)
logical :: conv_root, exst
! conv_root: true if linear system is converged
integer :: kter, iter0, ipol,jpol, ibnd, jbnd, iter, lter, &
ik, ig, irr, ir, is, nrec, ios
! counters
integer :: ltaver, lintercall
real(DP) :: tcpu, get_clock
! timing variables
REAL(kind=DP), ALLOCATABLE :: head(:,:),head_tmp(:)
COMPLEX(kind=DP) :: sca, sca2
REAL(kind=DP), ALLOCATABLE :: x(:),w(:), freqs(:)
! COMPLEX(kind=DP), ALLOCATABLE :: e_head(:,:)!wing of symmetric dielectric matrix (for G of local processor)
COMPLEX(kind=DP), ALLOCATABLE :: e_head_g(:),e_head_g_tmp(:,:,:)
COMPLEX(kind=DP), ALLOCATABLE :: e_head_pol(:,:,:)
INTEGER :: i, j,k,iun
REAL(kind=DP) :: ww, weight
COMPLEX(kind=DP), ALLOCATABLE :: tmp_g(:)
COMPLEX(kind=DP), ALLOCATABLE :: psi_v(:,:), prod(:)
COMPLEX(kind=DP), ALLOCATABLE :: pola_charge(:,:,:,:)
COMPLEX(kind=DP), ALLOCATABLE :: dpsi_ipol(:,:,:)
REAL(kind=DP), ALLOCATABLE :: epsilon_g(:,:,:)
INTEGER :: i_start,idumm,idumm1,idumm2,idumm3,ii
REAL(kind=DP) :: rdumm
COMPLEX(kind=DP), ALLOCATABLE :: d(:,:),f(:,:),omat(:,:,:)
INTEGER :: iv, info
COMPLEX(kind=DP), ALLOCATABLE :: z_dl(:),z_d(:),z_du(:),z_b(:)
COMPLEX(kind=DP) :: csca, csca1
COMPLEX(kind=DP), ALLOCATABLE :: t_out(:,:,:), psi_tmp(:)
TYPE(scf_type) :: wing
INTEGER :: n
INTEGER :: npwx_g
INTEGER :: ib,lenb,first_b,last_b,n_block,nbnd_block
INTEGER :: freq_block, m_block,first_f,last_f,lenf,im
write(stdout,*) 'Routine solve_head'
FLUSH(stdout)
if(grid_type==5) then
n=n_gauss
n_gauss=n+second_grid_n*(1+second_grid_i*2)
endif
!allocate(e_head(npw,n_gauss+1))
!allocate(e_head_pol(ngm,n_gauss+1,3))
!e_head(:,:) =(0.d0,0.d0)
allocate(x(2*n_gauss+1),w(2*n_gauss+1), freqs(n_gauss+1))
allocate(head(n_gauss+1,3),head_tmp(n_gauss+1))
head(:,:)=0.d0
allocate(prod(dfftp%nnr))
allocate (tmp_g(ngm))
! allocate( pola_charge(dfftp%nnr,nspin,3,n_gauss+1))
allocate(epsilon_g(3,3,n_gauss+1))
allocate(psi_tmp(npwx))
epsilon_g(:,:,:)=0.d0
! e_head_pol(:,:,:)=0.d0
! pola_charge(:,:,:,:)=0.d0
!setup Gauss Legendre frequency grid
!IT'S OF CAPITAL IMPORTANCE TO NULLIFY THE FOLLOWING ARRAYS
x(:)=0.d0
w(:)=0.d0
if(grid_type==0) then
call legzo(n_gauss*2+1,x,w)
freqs(1:n_gauss+1)=-x(n_gauss+1:2*n_gauss+1)*omega_gauss
else if(grid_type==2) then
call legzo(n_gauss,x,w)
freqs(1) = 0.d0
freqs(2:n_gauss+1)=(1.d0-x(1:n_gauss))*omega_gauss/2.d0
else if(grid_type==3) then!equally spaced grid
freqs(1) = 0.d0
do i=1,n_gauss
freqs(1+i)=omega_gauss*dble(i)/dble(n_gauss)
enddo
if(l_easy) then
freqs(1)=omega_gauss/dble(n_gauss)/4.d0
endif
else if(grid_type==4) then!equally spaced grid shifted of 1/2
freqs(1) = 0.d0
do i=1,n_gauss
freqs(i+1)=(omega_gauss/dble(n_gauss))*dble(i)-(0.5d0*omega_gauss/dble(n_gauss))
enddo
else!equally spaced grid more dense at -1 , 0 and 1
freqs(1)=0.d0
ii=2
do i=1,second_grid_n
freqs(ii)=(omega_gauss/dble(2*second_grid_n*n))*dble(i)-0.5d0*omega_gauss/dble(2*second_grid_n*n)
ii=ii+1
enddo
do j=1,second_grid_i
do i=1,second_grid_n
freqs(ii)=(omega_gauss/dble(2*second_grid_n*n))*dble(i+second_grid_n+2*second_grid_n*(j-1))&
&-0.5d0*omega_gauss/dble(2*second_grid_n*n)
ii=ii+1
enddo
freqs(ii)=omega_gauss/dble(n)*dble(j)
ii=ii+1
do i=1,second_grid_n
freqs(ii)=(omega_gauss/dble(2*second_grid_n*n))*dble(i+2*second_grid_n*j)&
&-0.5d0*omega_gauss/dble(2*second_grid_n*n)
ii=ii+1
enddo
enddo
do i=second_grid_i+1,n
freqs(ii)=omega_gauss/dble(n)*dble(i)
ii=ii+1
enddo
endif
do i=1,n_gauss+1
write(stdout,*) 'Freq',i,freqs(i)
enddo
FLUSH( stdout )
deallocate(x,w)
head(:,:)=0.d0
!if (lsda) call errore ('solve_head', ' LSDA not implemented', 1)
call start_clock ('solve_head')
allocate (ps (nbnd,nbnd))
ps (:,:) = (0.d0, 0.d0)
IF (ionode .AND. fildrho /= ' ') THEN
INQUIRE (UNIT = iudrho, OPENED = exst)
IF (exst) CLOSE (UNIT = iudrho, STATUS='keep')
CALL DIROPN (iudrho, TRIM(fildrho)//'.E', lrdrho, exst)
end if
!
!
! if q=0 for a metal: allocate and compute local DOS at Ef
!
if (degauss.ne.0.d0.or..not.lgamma) call errore ('solve_e', &
'called in the wrong case', 1)
!
!
! only one iteration is required
!
if(.not.l_scissor) scissor=0.d0
!loop on frequency blocks
if(len_head_block_freq==0) then
freq_block=n_gauss+1
m_block=1
else
m_block=(n_gauss+1)/len_head_block_freq
if(m_block*len_head_block_freq < (n_gauss+1)) m_block=m_block+1
if(len_head_block_freq>(n_gauss+1)) then
freq_block=n_gauss+1
else
freq_block=len_head_block_freq
endif
endif
!loop on frequency blocks
do im=1,m_block
epsilon_g=0.d0
write(stdout,*) 'FREQUENCY BLOCK : ', im
first_f=(im-1)*freq_block+1
last_f=im*freq_block
if(last_f>(n_gauss+1)) last_f=n_gauss+1
lenf=last_f-first_f+1
allocate( pola_charge(dfftp%nnr,nspin,3,lenf))
allocate(e_head_pol(ngm,lenf,3))
e_head_pol(:,:,:)=0.d0
pola_charge(:,:,:,:)=0.d0
!loop on k points
do ik=1, nksq
if(len_head_block_wfc==0) then
nbnd_block=nbnd_occ(ik)
n_block=1
else
n_block=nbnd_occ(ik)/len_head_block_wfc
if(n_block*len_head_block_wfc < nbnd_occ(ik)) n_block=n_block+1
if(len_head_block_wfc>nbnd_occ(ik)) then
nbnd_block=nbnd_occ(ik)
else
nbnd_block=len_head_block_wfc
endif
endif
write(stdout,*) 'ik:', ik
FLUSH(stdout)
weight = wk (ik)
ww = fpi * weight / omega
if (lsda) current_spin = isk (ik)
npw = ngk(ik)
!
! reads unperturbed wavefuctions psi_k in G_space, for all bands
!
if (nksq.gt.1) call get_buffer(evc, lrwfc, iuwfc, ik)
npwq = npw
call init_us_2 (npw, igk_k(1,ik), xk (1, ik), vkb)
!
! compute the kinetic energy
!
do ig = 1, npwq
g2kin (ig) = ( (xk (1,ik ) + g (1,igk_k (ig,ik)) ) **2 + &
(xk (2,ik ) + g (2,igk_k (ig,ik)) ) **2 + &
(xk (3,ik ) + g (3,igk_k (ig,ik)) ) **2 ) * tpiba2
enddo
!
do ib=1,n_block
write(stdout,*) 'BLOCK : ', ib
first_b=(ib-1)*nbnd_block+1
last_b=ib*nbnd_block
if(last_b>nbnd_occ(ik)) last_b=nbnd_occ(ik)
lenb=last_b-first_b+1
allocate (dpsi_ipol(npwx,lenb,3))
allocate(t_out(npwx,nsteps_lanczos,lenb))
allocate(psi_v(dffts%nnr, lenb))
dpsi_ipol(:,:,:)=(0.d0,0.d0)
!trasform valence wavefunctions to real space
do ibnd=1,lenb
psi_v(:,ibnd) = ( 0.D0, 0.D0 )
psi_v(dffts%nl(igk_k(1:npw,ik)),ibnd) = evc(1:npw,first_b+ibnd-1)
CALL invfft ('Wave', psi_v(:,ibnd), dffts)
enddo
!loop on carthesian directions
do ipol = 1,3
write(stdout,*) 'ipol:', ipol
FLUSH(stdout)
!
! computes/reads P_c^+ x psi_kpoint into dvpsi array
!
do jpol=1,3
call dvpsi_e (ik, jpol)
!
! Orthogonalize dvpsi to valence states: ps = <evc|dvpsi>
!
CALL ZGEMM( 'C', 'N', nbnd_occ (ik), nbnd_occ (ik), npw, &
(1.d0,0.d0), evc(1,1), npwx, dvpsi(1,1), npwx, (0.d0,0.d0), &
ps(1,1), nbnd )
#if defined(__MPI)
!call reduce (2 * nbnd * nbnd_occ (ik), ps)
call mp_sum(ps(1:nbnd_occ (ik),1:nbnd_occ (ik)),world_comm)
#endif
! dpsi is used as work space to store S|evc>
!
CALL calbec(npw,vkb,evc,becp,nbnd_occ(ik))
CALL s_psi (npwx, npw, nbnd_occ(ik), evc, dpsi)
!
! |dvpsi> = - (|dvpsi> - S|evc><evc|dvpsi>)
! note the change of sign!
!
CALL ZGEMM( 'N', 'N', npw, nbnd_occ(ik), nbnd_occ(ik), &
(1.d0,0.d0), dpsi(1,1), npwx, ps(1,1), nbnd, (-1.d0,0.d0), &
dvpsi(1,1), npwx )
!create lanczos chain for dvpsi
dpsi_ipol(1:npw,1:lenb,jpol)=dvpsi(1:npw,first_b:last_b)
enddo
dvpsi(1:npw,1:lenb)=dpsi_ipol(1:npw,1:lenb,ipol)
allocate(d(nsteps_lanczos,lenb),f(nsteps_lanczos,lenb))
allocate(omat(nsteps_lanczos,3,lenb))
write(stdout,*) 'before lanczos_state_k'
call lanczos_state_k(ik,lenb, nsteps_lanczos ,dvpsi,d,f,omat,dpsi_ipol,t_out)
write(stdout,*) 'after lanczos_state_k'
!loop on frequency
allocate(z_dl(nsteps_lanczos-1),z_d(nsteps_lanczos),z_du(nsteps_lanczos-1),z_b(nsteps_lanczos))
do i=1,lenf
!loop on valence states
do iv=1,lenb
!invert Hamiltonian
z_dl(1:nsteps_lanczos-1)=conjg(f(1:nsteps_lanczos-1,iv))
z_du(1:nsteps_lanczos-1)=f(1:nsteps_lanczos-1,iv)
z_d(1:nsteps_lanczos)=d(1:nsteps_lanczos,iv)+dcmplx(-et(first_b+iv-1,ik)-scissor(1)/rytoev,freqs(first_f+i-1))
z_b(:)=(0.d0,0.d0)
z_b(1)=dble(omat(1,ipol,iv))
call zgtsv(nsteps_lanczos,1,z_dl,z_d,z_du,z_b,nsteps_lanczos,info)
if(info/=0) then
write(stdout,*) 'problems with ZGTSV'
FLUSH(stdout)
stop
endif
do jpol=1,3
!multiply with overlap factors
call zgemm('T','N',1,1,nsteps_lanczos,(1.d0,0.d0),omat(:,jpol,iv),nsteps_lanczos&
&,z_b,nsteps_lanczos,(0.d0,0.d0),csca,1)
!update epsilon array NO SYMMETRIES for the moment
epsilon_g(jpol,ipol,i)=epsilon_g(jpol,ipol,i)+4.d0*ww*dble(csca)
enddo
!update part for wing calculation
call zgemm('N','N',npw,1,nsteps_lanczos,(1.d0,0.d0),t_out(:,:,iv),npwx,z_b,nsteps_lanczos,&
&(0.d0,0.d0),psi_tmp,npwx)
!fourier trasform
prod(:) = ( 0.D0, 0.D0 )
prod(dffts%nl(igk_k(1:npw,ik))) = psi_tmp(1:npw)
CALL invfft ('Wave', prod, dffts)
! product dpsi * psi_v
prod(1:dffts%nnr)=conjg(prod(1:dffts%nnr))*psi_v(1:dffts%nnr,iv)
if(doublegrid) call fft_interpolate(dffts, prod, dfftp, prod)
!US part STLL TO BE ADDED!!
pola_charge(1:dffts%nnr,1,ipol,i)=pola_charge(1:dffts%nnr,1,ipol,i)-prod(1:dffts%nnr)*ww
enddo
enddo
deallocate(z_dl,z_d,z_du,z_b)
deallocate(d,f,omat)
enddo
deallocate(dpsi_ipol)
deallocate(t_out)
deallocate(psi_v)
end do!on ib
enddo! on ik
!print out results
!
! symmetrize
!
do i=1,lenf
WRITE( stdout,'(/,10x,"Unsymmetrized in crystal axis ",/)')
WRITE( stdout,'(10x,"(",3f15.5," )")') ((epsilon_g(ipol,jpol,i),&
& ipol=1,3),jpol=1,3)
! call symtns (epsilon_g(:,:,i), nsym, s)
!
! pass to cartesian axis
!
WRITE( stdout,'(/,10x,"Symmetrized in crystal axis ",/)')
WRITE( stdout,'(10x,"(",3f15.5," )")') ((epsilon_g(ipol,jpol,i),&
& ipol=1,3),jpol=1,3)
! call trntns (epsilon_g(:,:,i), at, bg, 1)
call crys_to_cart ( epsilon_g(:,:,i) )
call symmatrix ( epsilon_g(:,:,i))
!
! add the diagonal part
!
!
! and print the result
!
WRITE( stdout, '(/,10x,"Dielectric constant in cartesian axis ",/)')
WRITE( stdout, '(10x,"(",3f18.9," )")') ((epsilon_g(ipol,jpol,i), ipol=1,3), jpol=1,3)
head(first_f+i-1,1)=epsilon_g(1,1,i)
head(first_f+i-1,2)=epsilon_g(2,2,i)
head(first_f+i-1,3)=epsilon_g(3,3,i)
call ph_set_upert_e()
#if defined(__MPI)
call mp_sum ( pola_charge(:,:,:,i) , inter_pool_comm )
call psymdvscf (pola_charge(:,:,:,i))
#else
call symdvscf (pola_charge(:,:,:,i))
#endif
call ph_deallocate_upert()
call create_scf_type ( wing, .true. )
do ipol=1,3
CALL fwfft ('Rho', pola_charge(1:dfftp%nnr,1,ipol,i), dfftp)
tmp_g(:)=(0.d0,0.d0)
tmp_g(gstart:ngm)=pola_charge(dfftp%nl(gstart:ngm),1,ipol,i)
wing%of_g(1:ngm,1)=-4.d0*tmp_g(1:ngm)
call write_wing ( wing, nspin,ipol,i)
!loop on frequency
do ig=gstart,ngm
e_head_pol(ig,i,ipol)=-4.d0*tmp_g(ig)
enddo
enddo
call destroy_scf_type (wing )
enddo
!writes on file wings
!collect data
!calculate total number of G for wave function
npwx_g=ngm
call mp_sum(npwx_g,world_comm)
allocate(e_head_g(ngm_g))
if(ionode) then
iun = find_free_unit()
if(im==1) then
open( unit= iun, file=trim(tmp_dir)//trim(prefix)//'.e_head', status='unknown',form='unformatted')
write(iun) n_gauss
write(iun) omega_gauss
write(iun) freqs(1:n_gauss+1)
write(iun) npwx_g
else
open( unit= iun, file=trim(tmp_dir)//trim(prefix)//'.e_head', status='old',form='unformatted',&
&position='append')
endif
endif
call mp_barrier( world_comm )
do i=1,lenf
do ipol=1,3
e_head_g(:)=(0.d0,0.d0)
call mergewf(e_head_pol(:,i,ipol),e_head_g ,ngm,ig_l2g,mpime,nproc,ionode_id,intra_pool_comm)
if(ionode) then
write(iun) e_head_g(1:npwx_g)
endif
enddo
enddo
call mp_barrier( world_comm )
if(ionode) close(iun)
deallocate(pola_charge)
deallocate(e_head_pol)
deallocate(e_head_g)
end do!im
!writes on file head
if(ionode) then
iun = find_free_unit()
open( unit= iun, file=trim(tmp_dir)//trim(prefix)//'.head', status='unknown',form='unformatted')
write(iun) n_gauss
write(iun) omega_gauss
write(iun) freqs(1:n_gauss+1)
write(iun) head(1:n_gauss+1,1)
write(iun) head(1:n_gauss+1,2)
write(iun) head(1:n_gauss+1,3)
close(iun)
endif
deallocate(psi_tmp)
deallocate(prod)
deallocate (ps)
deallocate(head,head_tmp,freqs)
deallocate( tmp_g)
deallocate(epsilon_g)
call stop_clock ('solve_head')
return
end subroutine solve_head
SUBROUTINE write_wing ( rho, nspin,ipol,iw)
USE kinds, ONLY : DP
USE io_files, ONLY : create_directory
USE io_base, ONLY : write_rhog, read_rhog
!
USE paw_variables, ONLY : okpaw
USE ldaU, ONLY : lda_plus_u
USE noncollin_module, ONLY : noncolin, domag
USE scf, ONLY : scf_type
!
USE cell_base, ONLY : bg, tpiba
USE gvect, ONLY : ig_l2g, mill
USE control_flags, ONLY : gamma_only
USE io_files, ONLY : seqopn, tmp_dir, prefix, postfix
USE io_global, ONLY : ionode, ionode_id, stdout
USE mp_pools, ONLY : my_pool_id
USE mp_bands, ONLY : my_bgrp_id, root_bgrp_id, &
root_bgrp, intra_bgrp_comm
USE mp_images, ONLY : intra_image_comm
USE mp, ONLY : mp_bcast
!
IMPLICIT NONE
TYPE(scf_type), INTENT(IN) :: rho
INTEGER, INTENT(IN) :: nspin
INTEGER, INTENT(IN) :: ipol!direction
INTEGER, INTENT(IN) :: iw !frequency
!
CHARACTER (LEN=256) :: dirname
LOGICAL :: lexist
INTEGER :: nspin_, iunocc, iunpaw, ierr
INTEGER, EXTERNAL :: find_free_unit
CHARACTER(5) :: nfile
CHARACTER :: npol
write(nfile,'(5i1)') &
& iw/10000,mod(iw,10000)/1000,mod(iw,1000)/100,mod(iw,100)/10,mod(iw,10)
write(npol,'(1i1)') ipol
dirname = TRIM(tmp_dir) // TRIM(prefix) // postfix
CALL create_directory( dirname )
! in the following case do not read or write polarization
IF ( noncolin .AND. .NOT.domag ) THEN
nspin_ = 1
ELSE
nspin_ = nspin
ENDIF
! Write G-space density
IF ( my_pool_id == 0 .AND. my_bgrp_id == root_bgrp_id ) &
CALL write_rhog( TRIM(dirname) // "wing_" // npol // "_" //nfile, &
root_bgrp, intra_bgrp_comm, &
bg(:,1)*tpiba, bg(:,2)*tpiba, bg(:,3)*tpiba, &
gamma_only, mill, ig_l2g, rho%of_g(:,1:nspin_) )
RETURN
END SUBROUTINE write_wing