quantum-espresso/PW/h_epsi_her_set.f90

1251 lines
42 KiB
Fortran
Executable File

!
! Copyright (C) 2005 Paolo Umari
! 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 h_epsi_her_set(pdir, e_field)
!-----------------------------------------------------------------------
!
! this subroutine builds the hermitean operators w_k w_k*,
! (as in Souza,et al. PRB B 69, 085106 (2004))
!
! wavefunctions from previous iteration are read into 'evcel'
! spin polarized systems supported only with fixed occupations
USE kinds, ONLY : DP
USE us
USE wvfct, ONLY : igk, g2kin, npwx, npw, nbnd
USE gsmooth, ONLY : nls, nr1s, nr2s, nr3s, nrx1s, nrx2s, nrx3s, nrxxs
USE ldaU, ONLY : lda_plus_u
USE lsda_mod, ONLY : current_spin, nspin
USE scf, ONLY : vrs
USE gvect
USE uspp
USE uspp_param, ONLY: upf, nh, nhm, nbetam, lmaxq
USE bp, ONLY : nppstr_3d, fact_hepsi, evcel, evcp=>evcelp, &
evcm=>evcelm, mapgp_global, mapgm_global, nx_el
USE basis
USE klist
USE cell_base, ONLY: at, alat, tpiba, omega, tpiba2
USE ions_base, ONLY: ityp, tau, nat,ntyp => nsp
USE io_files, ONLY: iunwfc, nwordwfc, iunefieldm, iunefieldp
USE buffers, ONLY: get_buffer
USE constants, ONLY : e2, pi, tpi, fpi
USE fixed_occ
USE mp, ONLY : mp_sum
USE mp_global, ONLY : intra_pool_comm
USE becmod, ONLY : calbec
!
implicit none
!
INTEGER, INTENT(in) :: pdir!direction on which the polarization is calculated
REAL(DP) :: e_field!electric field along pdir
!
! --- Internal definitions ---
COMPLEX(DP), ALLOCATABLE :: evct(:,:)!for temporary wavefunctios
INTEGER :: i
INTEGER :: igk1(npwx)
INTEGER :: igk0(npwx)
INTEGER :: ig
INTEGER :: info
INTEGER :: is
INTEGER :: iv
INTEGER :: ivpt(nbnd)
INTEGER :: j
INTEGER :: jkb
INTEGER :: jkb_bp
INTEGER :: jkb1
INTEGER :: jv
INTEGER :: m
INTEGER :: mb
INTEGER :: mk1
INTEGER :: mk2
INTEGER :: mk3
INTEGER :: n1
INTEGER :: n2
INTEGER :: n3
INTEGER :: na
INTEGER :: nb
INTEGER :: ng
INTEGER :: nhjkb
INTEGER :: nhjkbm
INTEGER :: nkbtona(nkb)
INTEGER :: nkbtonh(nkb)
INTEGER :: np
INTEGER :: npw1
INTEGER :: npw0
INTEGER :: nstring
INTEGER :: nt
INTEGER :: ik_stringa!k-point index inside string
REAL(dp) :: dk(3)
REAL(dp) :: dkm(3)! -dk
REAL(dp) :: dkmod
REAL(dp) :: eps
REAL(dp) :: fac
REAL(dp) :: g2kin_bp(npwx)
REAL(dp) :: gpar(3)
REAL(dp) :: gtr(3)
REAL(dp) :: gvec
REAL(dp), ALLOCATABLE :: ln(:,:,:)
REAL(dp), ALLOCATABLE :: ln0(:,:,:)!map g-space global to g-space k-point dependent
REAL(dp) :: qrad_dk(nbetam,nbetam,lmaxq,ntyp)
REAL(dp) :: ylm_dk(lmaxq*lmaxq)
COMPLEX(dp), ALLOCATABLE :: aux(:)
COMPLEX(dp), ALLOCATABLE :: aux0(:)
COMPLEX(dp) :: becp0(nkb,nbnd)
COMPLEX(dp) :: becp_bp(nkb,nbnd)
COMPLEX(dp) :: cdet(2)
COMPLEX(dp) :: cdwork(nbnd)
COMPLEX(dp) :: mat(nbnd,nbnd)
COMPLEX(dp) :: pref
COMPLEX(dp) :: q_dk(nhm,nhm,ntyp)
COMPLEX(dp) :: q_dkp(nhm,nhm,ntyp)!to store the terms T^dagger e^(iGx) T
COMPLEX(dp) :: struc(nat)
COMPLEX(dp) :: zdotc
COMPLEX(dp) :: sca,sca1
COMPLEX(dp) :: ps(nkb,nbnd)
INTEGER :: ijkb0, ibnd,jh, ih, ikb, ik
LOGICAL l_cal!flag for doing mat calculation, used for spin polarized systems
INTEGER, ALLOCATABLE :: map_g(:)
REAL(dp) :: dkfact
LOGICAL :: l_para! if true new parallel treatment
COMPLEX(kind=DP), ALLOCATABLE :: aux_g(:)
if(e_field==0.d0) return
! ------------------------------------------------------------------------- !
! INITIALIZATIONS
! ------------------------------------------------------------------------- !
if(pdir==3) then
l_para=.false.
else
l_para=.true.
endif
ALLOCATE( evct(npwx,nbnd))
ALLOCATE( map_g(npwx))
allocate( ln(-nr1:nr1,-nr2:nr2,-nr3:nr3),ln0(-nr1:nr1,-nr2:nr2,-nr3:nr3))
allocate(aux(ngm),aux0(ngm))
!determines the spin polarization
DO ik=1,nks
CALL get_buffer ( evcel, nwordwfc, iunwfc, nx_el(ik,pdir) )
if(nspin==2) then
if(ik <= nks/2) then
is = 1
else
is = 2
endif
else
is = 1
end if
ik_stringa=mod(ik-1,nppstr_3d(pdir))+1
nstring=nks/nppstr_3d(pdir)
! --- Define a small number ---
eps=0.000001d0
! --- Recalculate FFT correspondence (see ggen.f90) ---
DO ng=1,ngm
mk1=nint(g(1,ng)*at(1,1)+g(2,ng)*at(2,1)+g(3,ng)*at(3,1))
mk2=nint(g(1,ng)*at(1,2)+g(2,ng)*at(2,2)+g(3,ng)*at(3,2))
mk3=nint(g(1,ng)*at(1,3)+g(2,ng)*at(2,3)+g(3,ng)*at(3,3))
ln(mk1,mk2,mk3) = ng
END DO
if(okvan) then
! --- Initialize arrays ---
jkb_bp=0
DO nt=1,ntyp
DO na=1,nat
IF (ityp(na).eq.nt) THEN
DO i=1, nh(nt)
jkb_bp=jkb_bp+1
nkbtona(jkb_bp) = na
nkbtonh(jkb_bp) = i
END DO
END IF
END DO
END DO
endif
! --- Allocate memory for arrays ---
! ------------------------------------------------------------------------- !
! electronic polarization: set values for k-points strings !
! ------------------------------------------------------------------------- !
! ! --- Find vector along strings ---
if(nppstr_3d(pdir) .ne. 1) then
gpar(1)=(xk(1,nx_el(nppstr_3d(pdir),pdir))-xk(1,nx_el(1,pdir)))*&
&DBLE(nppstr_3d(pdir))/DBLE(nppstr_3d(pdir)-1)
gpar(2)=(xk(2,nx_el(nppstr_3d(pdir),pdir))-xk(2,nx_el(1,pdir)))*&
&DBLE(nppstr_3d(pdir))/DBLE(nppstr_3d(pdir)-1)
gpar(3)=(xk(3,nx_el(nppstr_3d(pdir),pdir))-xk(3,nx_el(1,pdir)))*&
&DBLE(nppstr_3d(pdir))/DBLE(nppstr_3d(pdir)-1)
gpar(:)=gpar(:)
gvec=dsqrt(gpar(1)**2+gpar(2)**2+gpar(3)**2)*tpiba
else
gpar(1)=0.d0
gpar(2)=0.d0
gpar(3)=0.d0
gpar(pdir)=1.d0/at(pdir,pdir)
gvec=tpiba/sqrt(at(pdir,1)**2.d0+at(pdir,2)**2.d0+at(pdir,3)**2.d0)
endif
! --- Find vector between consecutive points in strings ---
if(nppstr_3d(pdir).ne.1) then
dk(1)=xk(1,nx_el(2,pdir))-xk(1,nx_el(1,pdir))
dk(2)=xk(2,nx_el(2,pdir))-xk(2,nx_el(1,pdir))
dk(3)=xk(3,nx_el(2,pdir))-xk(3,nx_el(1,pdir))
dkmod=SQRT(dk(1)**2+dk(2)**2+dk(3)**2)*tpiba
else
dk(1)=0.d0
dk(2)=0.d0
dk(3)=0.d0
dk(pdir)=1.d0/at(pdir,pdir)
dkmod=tpiba/sqrt(at(pdir,1)**2.d0+at(pdir,2)**2.d0+at(pdir,3)**2.d0)
endif
call factor_a(pdir,at,dkfact)
dkfact=tpiba/dkfact/dble(nppstr_3d(pdir))
dkm(:)=-dk(:)
!calculates fact factor
!electronic charge is sqrt(2.) (Rydberg units)
!the factor (-i)/2 comes form operator Im
if(nspin == 1) then
!fact_hepsi(ik)=(0.d0,-1.d0)*efield*(2.d0)/2.d0/dkmod
fact_hepsi(nx_el(ik,pdir),pdir)=(0.d0,-1.d0)*e_field*dsqrt(2.d0)/2.d0/dkfact
else
!fact_hepsi(ik)=(0.d0,-1.d0)*efield*(2.d0)/2.d0/dkmod/DBLE(nspin)
fact_hepsi(nx_el(ik,pdir),pdir)=(0.d0,-1.d0)*e_field*dsqrt(2.d0)/2.d0/dkfact
endif
evcm(:,:,pdir)=(0.d0,0.d0)
evcp(:,:,pdir)=(0.d0,0.d0)
if(okvan) then
! ------------------------------------------------------------------------- !
! electronic polarization: structure factor !
! ------------------------------------------------------------------------- !
! --- Calculate structure factor e^{-i dk*R} ---
DO na=1,nat
fac=(dk(1)*tau(1,na)+dk(2)*tau(2,na)+dk(3)*tau(3,na))*tpi
struc(na)=CMPLX(cos(fac),-sin(fac),kind=DP)
END DO
! ------------------------------------------------------------------------- !
! electronic polarization: form factor !
! ------------------------------------------------------------------------- !
! --- Calculate Bessel transform of Q_ij(|r|) at dk [Q_ij^L(|r|)] ---
CALL calc_btq(dkmod,qrad_dk,0)
! --- Calculate the q-space real spherical harmonics at dk [Y_LM] ---
dkmod=dk(1)**2+dk(2)**2+dk(3)**2
CALL ylmr2(lmaxq*lmaxq, 1, dk, dkmod, ylm_dk)
! --- Form factor: 4 pi sum_LM c_ij^LM Y_LM(Omega) Q_ij^L(|r|) ---
q_dk=(0.d0,0.d0)
DO np =1, ntyp
if( upf(np)%tvanp ) then
DO iv = 1, nh(np)
DO jv = iv, nh(np)
call qvan3(iv,jv,np,pref,ylm_dk,qrad_dk)
q_dk(iv,jv,np) = omega*pref
q_dk(jv,iv,np) = omega*pref
ENDDO
ENDDO
endif
ENDDO
! --- Calculate the q-space real spherical harmonics at -dk [Y_LM] ---
dkmod=dkm(1)**2+dkm(2)**2+dkm(3)**2
CALL ylmr2(lmaxq*lmaxq, 1, dkm, dkmod, ylm_dk)
! --- Form factor: 4 pi sum_LM c_ij^LM Y_LM(Omega) Q_ij^L(|r|) ---
q_dkp=(0.d0,0.d0)
DO np =1, ntyp
if( upf(np)%tvanp ) then
DO iv = 1, nh(np)
DO jv = iv, nh(np)
call qvan3(iv,jv,np,pref,ylm_dk,qrad_dk)
q_dkp(iv,jv,np) = omega*pref
q_dkp(jv,iv,np) = omega*pref
ENDDO
ENDDO
endif
ENDDO
endif
! ------------------------------------------------------------------------- !
! electronic polarization: strings phases !
! ------------------------------------------------------------------------- !
!
!calculate the term S-1(k,k-1)
!
if(ik_stringa /= 1) then
CALL gk_sort(xk(1,nx_el(ik-1,pdir)),ngm,g,ecutwfc/tpiba2, &
& npw0,igk0,g2kin_bp)
CALL get_buffer (evct,nwordwfc,iunwfc,nx_el(ik-1,pdir))
!
! --- Calculate dot products between wavefunctions
! --- Dot wavefunctions and betas for PREVIOUS k-point ---
if(okvan) then
CALL init_us_2 (npw0,igk0,xk(1,nx_el(ik-1,pdir)),vkb)
CALL calbec( npw0, vkb, evct, becp0 )
endif
! --- Dot wavefunctions and betas for CURRENT k-point ---
CALL gk_sort(xk(1,nx_el(ik,pdir)),ngm,g,ecutwfc/tpiba2, &
& npw1,igk1,g2kin_bp)
! --- Recalculate FFT correspondence (see ggen.f90) ---
ln0=0!set array to 0
DO ig=1,npw1
mk1=nint(g(1,igk1(ig))*at(1,1)+g(2,igk1(ig))*at(2,1)+g(3,igk1(ig))*at(3,1))
mk2=nint(g(1,igk1(ig))*at(1,2)+g(2,igk1(ig))*at(2,2)+g(3,igk1(ig))*at(3,2))
mk3=nint(g(1,igk1(ig))*at(1,3)+g(2,igk1(ig))*at(2,3)+g(3,igk1(ig))*at(3,3))
ln0(mk1,mk2,mk3) = ig
END DO
if(okvan) then
CALL init_us_2 (npw1,igk1,xk(1,nx_el(ik,pdir)),vkb)
CALL calbec( npw1, vkb, evcel, becp_bp )
endif
! --- Matrix elements calculation ---
mat=(0.d0,0.d0)
DO nb=1,nbnd
DO mb=1,nbnd
!added support for spin polarized case
l_cal=.true.
if( nspin==2 .and. tfixed_occ) then
if(f_inp(nb,is)==0.d0 .or. f_inp(mb,is)==0.d0) then
l_cal=.false.
if(nb==mb) then
mat(nb,mb)=1.d0
else
mat(nb,mb)=0.d0
endif
endif
endif
if(l_cal) then
aux=(0.d0,0.d0)
aux0=(0.d0,0.d0)
DO ig=1,npw1
aux0(igk1(ig))=evcel(ig,nb)
END DO
DO ig=1,npw0
aux(igk0(ig))=evct(ig,mb)
END DO
mat(nb,mb) = zdotc(ngm,aux0,1,aux,1)
! --- Calculate the augmented part: ij=KB projectors, ---
! --- R=atom index: SUM_{ijR} q(ijR) <u_nk|beta_iR> ---
! --- <beta_jR|u_mk'> e^i(k-k')*R = ---
! --- also <u_nk|beta_iR>=<psi_nk|beta_iR> = becp^* ---
end if
END DO
END DO
call mp_sum( mat, intra_pool_comm )
DO nb=1,nbnd
DO mb=1,nbnd
l_cal=.true.
if( nspin==2 .and. tfixed_occ) then
if(f_inp(nb,is)==0.d0 .or. f_inp(mb,is)==0.d0) then
l_cal=.false.
if(nb==mb) then
mat(nb,mb)=1.d0
else
mat(nb,mb)=0.d0
endif
endif
endif
if(l_cal) then
if(okvan) then
pref = (0.d0,0.d0)
DO jkb=1,nkb
nhjkb = nkbtonh(jkb)
na = nkbtona(jkb)
np = ityp(na)
nhjkbm = nh(np)
jkb1 = jkb - nhjkb
DO j = 1,nhjkbm
pref = pref+CONJG(becp_bp(jkb,nb))*becp0(jkb1+j,mb) &
& *q_dkp(nhjkb,j,np)*CONJG(struc(na))
ENDDO
ENDDO
mat(nb,mb) = mat(nb,mb) + pref
endif
endif
ENDDO
ENDDO
! --- Calculate matrix inverse ---
CALL zgefa(mat,nbnd,nbnd,ivpt,info)
CALL errore('h_epsi_her','error in zgefa',abs(info))
CALL zgedi(mat,nbnd,nbnd,ivpt,cdet,cdwork,1)
! mat=S^-1(k,k-1)
do ig=1,npw0
gtr(1)=g(1,igk0(ig))
gtr(2)=g(2,igk0(ig))
gtr(3)=g(3,igk0(ig))
! --- Find crystal coordinates of gtr, n1,n2,n3 ---
! --- and the position ng in the ngm array ---
IF (gtr(1)**2+gtr(2)**2+gtr(3)**2 <= gcutm) THEN
n1=NINT(gtr(1)*at(1,1)+gtr(2)*at(2,1) &
& +gtr(3)*at(3,1))
n2=NINT(gtr(1)*at(1,2)+gtr(2)*at(2,2) &
& +gtr(3)*at(3,2))
n3=NINT(gtr(1)*at(1,3)+gtr(2)*at(2,3) &
& +gtr(3)*at(3,3))
ng=ln0(n1,n2,n3)
if(ng .gt. 0) then
do m=1,nbnd
do nb=1,nbnd
evcm(ng,m,pdir)=evcm(ng,m,pdir) + mat(nb,m)*evct(ig,nb)
enddo
enddo
end if
ENDIF
enddo
! add US terms into evcm
! calculate |beta_(ik,na,ih)>Q_dkp(na,ih,ij)<|beta_(ik-1,na,ih)|
if(okvan) then
evct(:,:) = (0.d0, 0.d0)
ps (:,:) = (0.d0, 0.d0)
ijkb0 = 0
do nt = 1, ntyp
do na = 1, nat
if (ityp (na) .eq.nt) then
do ibnd = 1, nbnd
do jh = 1, nh (nt)
jkb = ijkb0 + jh
do ih = 1, nh (nt)
ikb = ijkb0 + ih
ps (ikb, ibnd) = ps (ikb, ibnd) + &
q_dkp(ih,jh,ityp(na))*CONJG(struc(na))* becp0(jkb,ibnd)
enddo
enddo
enddo
ijkb0 = ijkb0 + nh (nt)
endif
enddo
enddo
call ZGEMM ('N', 'N', npw1, nbnd , nkb, (1.d0, 0.d0) , vkb, &!vkb is relative to the last ik read
npwx, ps, nkb, (1.d0, 0.d0) , evct, npwx)
do m=1,nbnd
do nb=1,nbnd
do ig=1,npw1
evcm(ig,m,pdir)=evcm(ig,m,pdir) + mat(nb,m)*evct(ig,nb)
enddo
enddo
enddo
endif
! --- End of dot products between wavefunctions and betas ---
ELSE
CALL gk_sort(xk(1,nx_el(ik+nppstr_3d(pdir)-1,pdir)),ngm,g,ecutwfc/tpiba2, &
& npw0,igk0,g2kin_bp)
CALL get_buffer (evct,nwordwfc,iunwfc,nx_el(ik+nppstr_3d(pdir)-1,pdir))
!
! --- Calculate dot products between wavefunctions
! --- Dot wavefunctions and betas for PREVIOUS k-point ---
if(okvan) then
CALL init_us_2 (npw0,igk0,xk(1,nx_el(ik+nppstr_3d(pdir)-1,pdir)),vkb)
CALL calbec( npw0, vkb, evct, becp0 )
endif
! --- Dot wavefunctions and betas for CURRENT k-point ---
CALL gk_sort(xk(1,nx_el(ik,pdir)),ngm,g,ecutwfc/tpiba2, &
& npw1,igk1,g2kin_bp)
! --- Recalculate FFT correspondence (see ggen.f90) ---
if(.not.l_para) then
ln0=0!set to 0
DO ig=1,npw1
mk1=nint(g(1,igk1(ig))*at(1,1)+g(2,igk1(ig))*at(2,1)+g(3,igk1(ig))*at(3,1))
mk2=nint(g(1,igk1(ig))*at(1,2)+g(2,igk1(ig))*at(2,2)+g(3,igk1(ig))*at(3,2))
mk3=nint(g(1,igk1(ig))*at(1,3)+g(2,igk1(ig))*at(2,3)+g(3,igk1(ig))*at(3,3))
ln0(mk1,mk2,mk3) = ig
END DO
endif
if(okvan) then
CALL init_us_2 (npw1,igk1,xk(1,nx_el(ik,pdir)),vkb)
CALL calbec( npw1, vkb, evcel, becp_bp )
endif
! --- Matrix elements calculation ---
mat=(0.d0,0.d0)
if(.not. l_para) then
map_g(:) = 0
do ig=1,npw0
! --- If k'=k+G_o, the relation psi_k+G_o (G-G_o) ---
! --- = psi_k(G) is used, gpar=G_o, gtr = G-G_o ---
gtr(1)=g(1,igk0(ig)) + gpar(1)
gtr(2)=g(2,igk0(ig)) + gpar(2)
gtr(3)=g(3,igk0(ig)) + gpar(3)
! --- Find crystal coordinates of gtr, n1,n2,n3 ---
! --- and the position ng in the ngm array ---
IF (gtr(1)**2+gtr(2)**2+gtr(3)**2 <= gcutm) THEN
n1=NINT(gtr(1)*at(1,1)+gtr(2)*at(2,1) &
+gtr(3)*at(3,1))
n2=NINT(gtr(1)*at(1,2)+gtr(2)*at(2,2) &
+gtr(3)*at(3,2))
n3=NINT(gtr(1)*at(1,3)+gtr(2)*at(2,3) &
+gtr(3)*at(3,3))
ng=ln(n1,n2,n3)
IF ((ABS(g(1,ng)-gtr(1)) > eps) .OR. &
(ABS(g(2,ng)-gtr(2)) > eps) .OR. &
(ABS(g(3,ng)-gtr(3)) > eps)) THEN
WRITE(6,*) ' error hepsiher: translated G=', &
gtr(1),gtr(2),gtr(3), &
' with crystal coordinates',n1,n2,n3, &
' corresponds to ng=',ng,' but G(ng)=', &
g(1,ng),g(2,ng),g(3,ng)
WRITE(6,*) ' probably because G_par is NOT', &
' a reciprocal lattice vector '
WRITE(6,*) ' Possible choices as smallest ', &
' G_par:'
DO i=1,50
WRITE(6,*) ' i=',i,' G=', &
g(1,i),g(2,i),g(3,i)
ENDDO
STOP
ENDIF
ELSE
WRITE(6,*) ' |gtr| > gcutm for gtr=', &
gtr(1),gtr(2),gtr(3)
STOP
END IF
map_g(ig)=ng
enddo
endif
DO nb=1,nbnd
DO mb=1,nbnd
l_cal=.true.
if( nspin==2 .and. tfixed_occ) then
if(f_inp(nb,is)==0.d0 .or. f_inp(mb,is)==0.d0) then
l_cal=.false.
if(nb==mb) then
mat(nb,mb)=1.d0
else
mat(nb,mb)=0.d0
endif
endif
endif
if(l_cal) then
if(.not.l_para) then
aux=(0.d0,0.d0)
aux0=(0.d0,0.d0)
DO ig=1,npw1
aux0(igk1(ig))=evcel(ig,nb)
END DO
do ig=1,npw0
!
aux(map_g(ig))=evct(ig,mb)
ENDDO
mat(nb,mb) = zdotc(ngm,aux0,1,aux,1)
else
!allocate global array
allocate(aux_g(ngm_g))
aux_g=(0.d0,0.d0)
!put psi1 on global array
do ig=1,npw0
aux_g(mapgp_global(ig_l2g(igk0(ig)),pdir))=evct(ig,mb)
enddo
call mp_sum(aux_g(:))
sca=(0.d0,0.d0)
!do scalar product
do ig=1,npw1
sca=sca+conjg(evcel(ig,nb))*aux_g(ig_l2g(igk1(ig)))
enddo
! mp_sum is done later!!!
mat(nb,mb)=sca
deallocate(aux_g)
endif
endif
END DO
END DO
call mp_sum( mat, intra_pool_comm )
DO nb=1,nbnd
DO mb=1,nbnd
l_cal=.true.
if( nspin==2 .and. tfixed_occ) then
if(f_inp(nb,is)==0.d0 .or. f_inp(mb,is)==0.d0) then
l_cal=.false.
if(nb==mb) then
mat(nb,mb)=1.d0
else
mat(nb,mb)=0.d0
endif
endif
endif
if(l_cal) then
! --- Calculate the augmented part: ij=KB projectors, ---
! --- R=atom index: SUM_{ijR} q(ijR) <u_nk|beta_iR> ---
! --- <beta_jR|u_mk'> e^i(k-k')*R = ---
! --- also <u_nk|beta_iR>=<psi_nk|beta_iR> = becp^* ---
if (okvan) then
pref = (0.d0,0.d0)
DO jkb=1,nkb
nhjkb = nkbtonh(jkb)
na = nkbtona(jkb)
np = ityp(na)
nhjkbm = nh(np)
jkb1 = jkb - nhjkb
DO j = 1,nhjkbm
pref = pref+CONJG(becp_bp(jkb,nb))*becp0(jkb1+j,mb) &
*q_dkp(nhjkb,j,np)*CONJG(struc(na))
ENDDO
ENDDO
mat(nb,mb) = mat(nb,mb) + pref
endif
endif
ENDDO
ENDDO
! --- Calculate matrix inverse ---
CALL zgefa(mat,nbnd,nbnd,ivpt,info)
CALL errore('h_epsi_her','error in zgefa',abs(info))
CALL zgedi(mat,nbnd,nbnd,ivpt,cdet,cdwork,1)
! mat=S^-1(k,k-1)
if(.not.l_para) then
do ig=1,npw0
gtr(1)=g(1,igk0(ig)) + gpar(1)
gtr(2)=g(2,igk0(ig)) + gpar(2)
gtr(3)=g(3,igk0(ig)) + gpar(3)
! --- Find crystal coordinates of gtr, n1,n2,n3 ---
! --- and the position ng in the ngm array ---
IF (gtr(1)**2+gtr(2)**2+gtr(3)**2 <= gcutm) THEN
n1=NINT(gtr(1)*at(1,1)+gtr(2)*at(2,1) &
& +gtr(3)*at(3,1))
n2=NINT(gtr(1)*at(1,2)+gtr(2)*at(2,2) &
& +gtr(3)*at(3,2))
n3=NINT(gtr(1)*at(1,3)+gtr(2)*at(2,3) &
& +gtr(3)*at(3,3))
ng=ln0(n1,n2,n3)
if(ng .gt. 0) then
do m=1,nbnd
do nb=1,nbnd
evcm(ng,m,pdir)=evcm(ng,m,pdir) + mat(nb,m)*evct(ig,nb)
enddo
enddo
endif
ENDIF
enddo
else
!allocate
allocate(aux_g(ngm_g))
!loop on nb
do nb=1,nbnd
aux_g(:)=(0.d0,0.d0)
do ig=1,npw0
aux_g(mapgp_global(ig_l2g(igk0(ig)),pdir))=evct(ig,nb)
enddo
!put evct on global array
call mp_sum(aux_g(:))
do m=1,nbnd
do ig=1,npw1
evcm(ig,m,pdir)=evcm(ig,m,pdir)+mat(nb,m)*aux_g(ig_l2g(igk1(ig)))
enddo
enddo
enddo
deallocate(aux_g)
endif
if(okvan) then
evct(:,:) = (0.d0, 0.d0)
ps (:,:) = (0.d0, 0.d0)
ijkb0 = 0
do nt = 1, ntyp
do na = 1, nat
if (ityp (na) .eq.nt) then
do ibnd = 1, nbnd
do jh = 1, nh (nt)
jkb = ijkb0 + jh
do ih = 1, nh (nt)
ikb = ijkb0 + ih
ps (ikb, ibnd) = ps (ikb, ibnd) + &
q_dkp(ih,jh,ityp(na))*CONJG(struc(na))* becp0(jkb,ibnd)
enddo
enddo
enddo
ijkb0 = ijkb0 + nh (nt)
endif
enddo
enddo
call ZGEMM ('N', 'N', npw1, nbnd , nkb, (1.d0, 0.d0) , vkb, &!vkb is relative to the last ik read
npwx, ps, nkb, (1.d0, 0.d0) , evct, npwx)
do m=1,nbnd
do nb=1,nbnd
do ig=1,npw1
evcm(ig,m,pdir)=evcm(ig,m,pdir) + mat(nb,m)*evct(ig,nb)
enddo
enddo
enddo
endif
ENDIF
! calculate S-1(k,k+1)
!
if(ik_stringa /= nppstr_3d(pdir)) then
CALL gk_sort(xk(1,nx_el(ik+1,pdir)),ngm,g,ecutwfc/tpiba2, &
& npw0,igk0,g2kin_bp)
CALL get_buffer (evct,nwordwfc,iunwfc,nx_el(ik+1,pdir))
!
! --- Calculate dot products between wavefunctions
! --- Dot wavefunctions and betas for PREVIOUS k-point ---
if(okvan) then
CALL init_us_2 (npw0,igk0,xk(1,nx_el(ik+1,pdir)),vkb)
CALL calbec( npw0, vkb, evct, becp0)
endif
! --- Dot wavefunctions and betas for CURRENT k-point ---
CALL gk_sort(xk(1,nx_el(ik,pdir)),ngm,g,ecutwfc/tpiba2, &
& npw1,igk1,g2kin_bp)
! --- Recalculate FFT correspondence (see ggen.f90) ---
ln0=0!set to 0
DO ig=1,npw1
mk1=nint(g(1,igk1(ig))*at(1,1)+g(2,igk1(ig))*at(2,1)+g(3,igk1(ig))*at(3,1))
mk2=nint(g(1,igk1(ig))*at(1,2)+g(2,igk1(ig))*at(2,2)+g(3,igk1(ig))*at(3,2))
mk3=nint(g(1,igk1(ig))*at(1,3)+g(2,igk1(ig))*at(2,3)+g(3,igk1(ig))*at(3,3))
ln0(mk1,mk2,mk3) = ig
END DO
if(okvan) then
CALL init_us_2 (npw1,igk1,xk(1,nx_el(ik,pdir)),vkb)
CALL calbec( npw1, vkb, evcel, becp_bp )
endif
! --- Matrix elements calculation ---
mat=(0.d0,0.d0)
DO nb=1,nbnd
DO mb=1,nbnd
l_cal=.true.
if( nspin==2 .and. tfixed_occ) then
if(f_inp(nb,is)==0.d0 .or. f_inp(mb,is)==0.d0) then
l_cal=.false.
if(nb==mb) then
mat(nb,mb)=1.d0
else
mat(nb,mb)=0.d0
endif
endif
endif
if(l_cal) then
aux=(0.d0,0.d0)
aux0=(0.d0,0.d0)
DO ig=1,npw1
aux0(igk1(ig))=evcel(ig,nb)
END DO
DO ig=1,npw0
aux(igk0(ig))=evct(ig,mb)
END DO
mat(nb,mb) = zdotc(ngm,aux0,1,aux,1)
! --- Calculate the augmented part: ij=KB projectors, ---
! --- R=atom index: SUM_{ijR} q(ijR) <u_nk|beta_iR> ---
! --- <beta_jR|u_mk'> e^i(k-k')*R = ---
! --- also <u_nk|beta_iR>=<psi_nk|beta_iR> = becp^* ---
endif
END DO
END DO
call mp_sum( mat, intra_pool_comm )
DO nb=1,nbnd
DO mb=1,nbnd
l_cal=.true.
if( nspin==2 .and. tfixed_occ) then
if(f_inp(nb,is)==0.d0 .or. f_inp(mb,is)==0.d0) then
l_cal=.false.
if(nb==mb) then
mat(nb,mb)=1.d0
else
mat(nb,mb)=0.d0
endif
endif
endif
if(l_cal) then
if(okvan) then
pref = (0.d0,0.d0)
DO jkb=1,nkb
nhjkb = nkbtonh(jkb)
na = nkbtona(jkb)
np = ityp(na)
nhjkbm = nh(np)
jkb1 = jkb - nhjkb
DO j = 1,nhjkbm
pref = pref+CONJG(becp_bp(jkb,nb))*becp0(jkb1+j,mb) &
*q_dk(nhjkb,j,np)*struc(na)
ENDDO
ENDDO
mat(nb,mb) = mat(nb,mb) + pref
endif
endif
ENDDO
ENDDO
! --- Calculate matrix inverse ---
CALL zgefa(mat,nbnd,nbnd,ivpt,info)
CALL errore('h_epsi_her','error in zgefa',abs(info))
CALL zgedi(mat,nbnd,nbnd,ivpt,cdet,cdwork,1)
! mat=S^-1(k,k-1)
do ig=1,npw0
gtr(1)=g(1,igk0(ig))
gtr(2)=g(2,igk0(ig))
gtr(3)=g(3,igk0(ig))
! --- Find crystal coordinates of gtr, n1,n2,n3 ---
! --- and the position ng in the ngm array ---
IF (gtr(1)**2+gtr(2)**2+gtr(3)**2 <= gcutm) THEN
n1=NINT(gtr(1)*at(1,1)+gtr(2)*at(2,1) &
& +gtr(3)*at(3,1))
n2=NINT(gtr(1)*at(1,2)+gtr(2)*at(2,2) &
& +gtr(3)*at(3,2))
n3=NINT(gtr(1)*at(1,3)+gtr(2)*at(2,3) &
& +gtr(3)*at(3,3))
ng=ln0(n1,n2,n3)
if(ng .gt. 0) then
do m=1,nbnd
do nb=1,nbnd
evcp(ng,m,pdir)=evcp(ng,m,pdir) + mat(nb,m)*evct(ig,nb)
enddo
enddo
endif
ENDIF
enddo
if(okvan) then
evct(:,:) = (0.d0, 0.d0)
ps (:,:) = (0.d0, 0.d0)
ijkb0 = 0
do nt = 1, ntyp
do na = 1, nat
if (ityp (na) .eq.nt) then
do ibnd = 1, nbnd
do jh = 1, nh (nt)
jkb = ijkb0 + jh
do ih = 1, nh (nt)
ikb = ijkb0 + ih
ps (ikb, ibnd) = ps (ikb, ibnd) + &
q_dk(ih,jh,ityp(na))*struc(na)* becp0(jkb,ibnd)
enddo
enddo
enddo
ijkb0 = ijkb0 + nh (nt)
endif
enddo
enddo
call ZGEMM ('N', 'N', npw1, nbnd , nkb, (1.d0, 0.d0) , vkb, &!vkb is relative to the last ik read
npwx, ps, nkb, (1.d0, 0.d0) , evct, npwx)
do m=1,nbnd
do nb=1,nbnd
do ig=1,npw1
evcp(ig,m,pdir)=evcp(ig,m,pdir) + mat(nb,m)*evct(ig,nb)
enddo
enddo
enddo
endif
! --- End of dot products between wavefunctions and betas ---
else
CALL gk_sort(xk(1,nx_el(ik-nppstr_3d(pdir)+1,pdir)),ngm,g,ecutwfc/tpiba2, &
& npw0,igk0,g2kin_bp)
CALL get_buffer (evct,nwordwfc,iunwfc,nx_el(ik-nppstr_3d(pdir)+1,pdir))
!
! --- Calculate dot products between wavefunctions
! --- Dot wavefunctions and betas for PREVIOUS k-point ---
if(okvan) then
CALL init_us_2 (npw0,igk0,xk(1,nx_el(ik-nppstr_3d(pdir)+1,pdir)),vkb)
CALL calbec( npw0, vkb, evct, becp0 )
endif
! --- Dot wavefunctions and betas for CURRENT k-point ---
CALL gk_sort(xk(1,nx_el(ik,pdir)),ngm,g,ecutwfc/tpiba2, &
& npw1,igk1,g2kin_bp)
! --- Recalculate FFT correspondence (see ggen.f90) ---
if(.not.l_para) then
ln0=0! set to 0
DO ig=1,npw1
mk1=nint(g(1,igk1(ig))*at(1,1)+g(2,igk1(ig))*at(2,1)+g(3,igk1(ig))*at(3,1))
mk2=nint(g(1,igk1(ig))*at(1,2)+g(2,igk1(ig))*at(2,2)+g(3,igk1(ig))*at(3,2))
mk3=nint(g(1,igk1(ig))*at(1,3)+g(2,igk1(ig))*at(2,3)+g(3,igk1(ig))*at(3,3))
ln0(mk1,mk2,mk3) = ig
END DO
endif
if(okvan) then
CALL init_us_2 (npw1,igk1,xk(1,nx_el(ik,pdir)),vkb)
CALL calbec( npw1, vkb, evcel, becp_bp )
endif
! --- Matrix elements calculation ---
if(.not.l_para) then
map_g(:) = 0
do ig=1,npw0
! --- If k'=k+G_o, the relation psi_k+G_o (G-G_o) ---
! --- = psi_k(G) is used, gpar=G_o, gtr = G-G_o ---
gtr(1)=g(1,igk0(ig)) - gpar(1)
gtr(2)=g(2,igk0(ig)) - gpar(2)
gtr(3)=g(3,igk0(ig)) - gpar(3)
! --- Find crystal coordinates of gtr, n1,n2,n3 ---
! --- and the position ng in the ngm array ---
IF (gtr(1)**2+gtr(2)**2+gtr(3)**2 <= gcutm) THEN
n1=NINT(gtr(1)*at(1,1)+gtr(2)*at(2,1) &
+gtr(3)*at(3,1))
n2=NINT(gtr(1)*at(1,2)+gtr(2)*at(2,2) &
+gtr(3)*at(3,2))
n3=NINT(gtr(1)*at(1,3)+gtr(2)*at(2,3) &
+gtr(3)*at(3,3))
ng=ln(n1,n2,n3)
IF ((ABS(g(1,ng)-gtr(1)) > eps) .OR. &
(ABS(g(2,ng)-gtr(2)) > eps) .OR. &
(ABS(g(3,ng)-gtr(3)) > eps)) THEN
WRITE(6,*) ' error hepsiher: translated G=', &
gtr(1),gtr(2),gtr(3), &
' with crystal coordinates',n1,n2,n3, &
' corresponds to ng=',ng,' but G(ng)=', &
g(1,ng),g(2,ng),g(3,ng)
WRITE(6,*) ' probably because G_par is NOT', &
' a reciprocal lattice vector '
WRITE(6,*) ' Possible choices as smallest ', &
' G_par:'
DO i=1,50
WRITE(6,*) ' i=',i,' G=', &
g(1,i),g(2,i),g(3,i)
ENDDO
STOP
ENDIF
ELSE
WRITE(6,*) ' |gtr| > gcutm for gtr=', &
gtr(1),gtr(2),gtr(3)
STOP
END IF
map_g(ig)=ng
ENDDO
endif
mat=(0.d0,0.d0)
DO nb=1,nbnd
DO mb=1,nbnd
l_cal=.true.
if( nspin==2 .and. tfixed_occ) then
if(f_inp(nb,is)==0.d0 .or. f_inp(mb,is)==0.d0) then
l_cal=.false.
if(nb==mb) then
mat(nb,mb)=1.d0
else
mat(nb,mb)=0.d0
endif
endif
endif
if(l_cal) then
if(.not.l_para) then
aux=(0.d0,0.d0)
aux0=(0.d0,0.d0)
DO ig=1,npw1
aux0(igk1(ig))=evcel(ig,nb)
END DO
do ig=1,npw0
aux(map_g(ig))=evct(ig,mb)
ENDDO
mat(nb,mb) = zdotc(ngm,aux0,1,aux,1)
else
!allocate global array
allocate(aux_g(ngm_g))
aux_g=(0.d0,0.d0)
!put psi1 on global array
do ig=1,npw0
aux_g(mapgm_global(ig_l2g(igk0(ig)),pdir))=evct(ig,mb)
enddo
call mp_sum(aux_g(:))
sca=(0.d0,0.d0)
!do scalar product
do ig=1,npw1
sca=sca+conjg(evcel(ig,nb))*aux_g(ig_l2g(igk1(ig)))
enddo
! mp_sum is done later!!!
mat(nb,mb)=sca
deallocate(aux_g)
endif
endif
END DO
END DO
call mp_sum( mat, intra_pool_comm )
DO nb=1,nbnd
DO mb=1,nbnd
l_cal=.true.
if( nspin==2 .and. tfixed_occ) then
if(f_inp(nb,is)==0.d0 .or. f_inp(mb,is)==0.d0) then
l_cal=.false.
if(nb==mb) then
mat(nb,mb)=1.d0
else
mat(nb,mb)=0.d0
endif
endif
endif
if(l_cal) then
if(okvan) then
pref = (0.d0,0.d0)
DO jkb=1,nkb
nhjkb = nkbtonh(jkb)
na = nkbtona(jkb)
np = ityp(na)
nhjkbm = nh(np)
jkb1 = jkb - nhjkb
DO j = 1,nhjkbm
pref = pref+CONJG(becp_bp(jkb,nb))*becp0(jkb1+j,mb) &
*q_dk(nhjkb,j,np)*struc(na)
ENDDO
ENDDO
mat(nb,mb) = mat(nb,mb) + pref
endif
endif
ENDDO
ENDDO
! --- Calculate matrix inverse ---
CALL zgefa(mat,nbnd,nbnd,ivpt,info)
CALL errore('h_epsi_her','error in zgefa',abs(info))
CALL zgedi(mat,nbnd,nbnd,ivpt,cdet,cdwork,1)
! mat=S^-1(k,k-1)
if(.not.l_para) then
do ig=1,npw0
gtr(1)=g(1,igk0(ig)) - gpar(1)
gtr(2)=g(2,igk0(ig)) - gpar(2)
gtr(3)=g(3,igk0(ig)) - gpar(3)
! --- Find crystal coordinates of gtr, n1,n2,n3 ---
! --- and the position ng in the ngm array ---
IF (gtr(1)**2+gtr(2)**2+gtr(3)**2 <= gcutm) THEN
n1=NINT(gtr(1)*at(1,1)+gtr(2)*at(2,1) &
& +gtr(3)*at(3,1))
n2=NINT(gtr(1)*at(1,2)+gtr(2)*at(2,2) &
& +gtr(3)*at(3,2))
n3=NINT(gtr(1)*at(1,3)+gtr(2)*at(2,3) &
& +gtr(3)*at(3,3))
ng=ln0(n1,n2,n3)
if(ng .gt. 0) then
do m=1,nbnd
do nb=1,nbnd
evcp(ng,m,pdir)=evcp(ng,m,pdir) + mat(nb,m)*evct(ig,nb)
end do
enddo
end if
ENDIF
enddo
else
!allocate
allocate(aux_g(ngm_g))
!loop on nb
do nb=1,nbnd
aux_g(:)=(0.d0,0.d0)
do ig=1,npw0
aux_g(mapgm_global(ig_l2g(igk0(ig)),pdir))=evct(ig,nb)
enddo
!put evct on global array
call mp_sum(aux_g(:))
do m=1,nbnd
do ig=1,npw1
evcp(ig,m,pdir)=evcp(ig,m,pdir)+mat(nb,m)*aux_g(ig_l2g(igk1(ig)))
enddo
enddo
enddo
deallocate(aux_g)
endif
if(okvan) then
evct(:,:) = (0.d0, 0.d0)
ps (:,:) = (0.d0, 0.d0)
ijkb0 = 0
do nt = 1, ntyp
do na = 1, nat
if (ityp (na) .eq.nt) then
do ibnd = 1, nbnd
do jh = 1, nh (nt)
jkb = ijkb0 + jh
do ih = 1, nh (nt)
ikb = ijkb0 + ih
ps (ikb, ibnd) = ps (ikb, ibnd) + &
q_dk(ih,jh,ityp(na))*struc(na)* becp0(jkb,ibnd)
enddo
enddo
enddo
ijkb0 = ijkb0 + nh (nt)
endif
enddo
enddo
call ZGEMM ('N', 'N', npw1, nbnd , nkb, (1.d0, 0.d0) , vkb, &!vkb is relative to the ik read
npwx, ps, nkb, (1.d0, 0.d0) , evct, npwx)
do m=1,nbnd
do nb=1,nbnd
do ig=1,npw1
evcp(ig,m,pdir)=evcp(ig,m,pdir) + mat(nb,m)*evct(ig,nb)
enddo
enddo
enddo
endif
ENDIF
!writes projectors to disk
call davcio(evcm(:,:,pdir), 2*nwordwfc,iunefieldm,nx_el(ik,pdir)+(pdir-1)*nks,1)
call davcio(evcp(:,:,pdir), 2*nwordwfc,iunefieldp,nx_el(ik,pdir)+(pdir-1)*nks,1)
END DO !on ik
DEALLOCATE( evct)
DEALLOCATE( map_g)
deallocate(ln,ln0)
DEALLOCATE(aux,aux0)
! --
!------------------------------------------------------------------------------!
return
END SUBROUTINE h_epsi_her_set
!==============================================================================!
SUBROUTINE factor_a(dir, a,fact)
USE kinds, ONLY : DP
IMPLICIT NONE
REAL(kind=DP):: a(3,3),fact
INTEGER :: dir
INTEGER :: d1,d2
REAL(kind=DP) :: v(3), sca
if(dir==1) then
d1=2
d2=3
else if(dir==2) then
d1=3
d2=1
else if(dir==3) then
d1=1
d2=2
endif
!calculate vect(a(d1,:) X a(d2,:)
v(1)=a(2,d1)*a(3,d2)-a(3,d1)*a(2,d2)
v(2)=-a(1,d1)*a(3,d2)+a(3,d1)*a(1,d2)
v(3)=a(1,d1)*a(2,d2)-a(2,d1)*a(1,d2)
!normalize v
sca=sqrt(v(1)**2.d0+v(2)**2.d0+v(3)**2.d0)
v(:)=v(:)/sca
!calculate a(dir:)*v(:)
fact=v(1)*a(1,dir)+v(2)*a(2,dir)+v(3)*a(3,dir)
fact=abs(fact)
return
END SUBROUTINE factor_a