quantum-espresso/PHonon/PH/elphon.f90

1724 lines
56 KiB
Fortran

!
! Copyright (C) 2001-2018 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 elphon()
!-----------------------------------------------------------------------
!
! Electron-phonon calculation from data saved in fildvscf
!
USE kinds, ONLY : DP
USE constants, ONLY : amu_ry, RY_TO_THZ, RY_TO_CMM1
USE cell_base, ONLY : celldm, omega, ibrav, at, bg
USE ions_base, ONLY : nat, ntyp => nsp, ityp, tau, amass
USE gvecs, ONLY: doublegrid
USE fft_base, ONLY : dfftp, dffts
USE fft_interfaces, ONLY : fft_interpolate
USE noncollin_module, ONLY : nspin_mag, noncolin, m_loc
USE lsda_mod, ONLY : nspin
USE uspp, ONLY: okvan
USE paw_variables, ONLY : okpaw
USE el_phon, ONLY : done_elph
USE dynmat, ONLY : dyn, w2
USE modes, ONLY : npert, nirr, u
USE uspp_param, ONLY : nhm
USE control_ph, ONLY : trans, xmldyn
USE output, ONLY : fildyn,fildvscf
USE io_dyn_mat, ONLY : read_dyn_mat_param, read_dyn_mat_header, &
read_dyn_mat, read_dyn_mat_tail
USE units_ph, ONLY : iudyn, lrdrho, iudvscf, iuint3paw, lint3paw
USE dfile_star, ONLY : dvscf_star
USE mp_bands, ONLY : intra_bgrp_comm, me_bgrp, root_bgrp
USE mp, ONLY : mp_bcast
USE io_global, ONLY: stdout
USE lrus, ONLY : int3, int3_nc, int3_paw
USE qpoint, ONLY : xq
USE dvscf_interpolate, ONLY : ldvscf_interpolate, dvscf_r2q
!
IMPLICIT NONE
!
INTEGER :: irr, imode0, ipert, is, npe
! counter on the representations
! counter on the modes
! the change of Vscf due to perturbations
INTEGER :: i,j
COMPLEX(DP), ALLOCATABLE :: dvscfin_all(:, :, :)
!! dvscfin for all modes. Used when doing dvscf_r2q interpolation.
COMPLEX(DP), POINTER :: dvscfin(:,:,:), dvscfins (:,:,:)
COMPLEX(DP), allocatable :: phip (:, :, :, :)
INTEGER :: ntyp_, nat_, ibrav_, nspin_mag_, mu, nu, na, nb, nta, ntb, nqs_
REAL(DP) :: celldm_(6), w1
CHARACTER(LEN=3) :: atm(ntyp)
CALL start_clock ('elphon')
if(dvscf_star%basis.eq.'cartesian') then
write(stdout,*) 'Setting patterns to identity'
u=(0.d0,0.d0)
do irr=1,3*nat
u(irr,irr)=(1.d0,0.d0)
enddo
endif
!
! If ldvscf_interpolate, use Fourier interpolation instead of reading dVscf
!
IF (ldvscf_interpolate) THEN
!
WRITE (6, '(5x,a)') "Fourier interpolating dVscf"
ALLOCATE(dvscfin_all(dfftp%nnr, nspin_mag, 3 * nat))
CALL dvscf_r2q(xq, u, dvscfin_all)
!
ELSE
WRITE (6, '(5x,a)') "Reading dVscf from file "//trim(fildvscf)
ENDIF
!
! read Delta Vscf and calculate electron-phonon coefficients
!
imode0 = 0
DO irr = 1, nirr
npe=npert(irr)
ALLOCATE (dvscfin (dfftp%nnr, nspin_mag , npe) )
IF (okvan) THEN
ALLOCATE (int3 ( nhm, nhm, nat, nspin_mag, npe))
IF (okpaw) ALLOCATE (int3_paw (nhm, nhm, nat, nspin_mag, npe))
IF (noncolin) ALLOCATE(int3_nc( nhm, nhm, nat, nspin, npe))
ENDIF
DO ipert = 1, npe
IF (ldvscf_interpolate) THEN
dvscfin(:, :, ipert) = dvscfin_all(:, :, imode0 + ipert)
ELSE
CALL davcio_drho ( dvscfin(1,1,ipert), lrdrho, iudvscf, &
imode0 + ipert, -1 )
ENDIF
IF (okpaw .AND. me_bgrp==0) &
CALL davcio( int3_paw(:,:,:,:,ipert), lint3paw, &
iuint3paw, imode0 + ipert, - 1 )
END DO
IF (okpaw) CALL mp_bcast(int3_paw, root_bgrp, intra_bgrp_comm)
IF (doublegrid) THEN
ALLOCATE (dvscfins (dffts%nnr, nspin_mag , npert(irr)) )
DO is = 1, nspin_mag
DO ipert = 1, npe
CALL fft_interpolate (dfftp, dvscfin(:,is,ipert), dffts, dvscfins(:,is,ipert))
ENDDO
ENDDO
ELSE
dvscfins => dvscfin
ENDIF
CALL newdq (dvscfin, npert(irr))
CALL elphel (irr, npert (irr), imode0, dvscfins)
!
imode0 = imode0 + npe
IF (doublegrid) DEALLOCATE (dvscfins)
DEALLOCATE (dvscfin)
IF (okvan) THEN
DEALLOCATE (int3)
IF (okpaw) DEALLOCATE (int3_paw)
IF (noncolin) DEALLOCATE(int3_nc)
ENDIF
ENDDO
!
IF (ldvscf_interpolate) DEALLOCATE(dvscfin_all)
!
! now read the eigenvalues and eigenvectors of the dynamical matrix
! calculated in a previous run
!
IF (.NOT.trans) THEN
IF (.NOT. xmldyn) THEN
WRITE (6, '(5x,a)') "Reading dynamics matrix from file "//trim(fildyn)
CALL readmat (iudyn, ibrav, celldm, nat, ntyp, &
ityp, omega, amass, tau, xq, w2, dyn)
ELSE
allocate( phip(3,3,nat,nat) )
CALL read_dyn_mat_param(fildyn, ntyp_, nat_)
IF ( ntyp_ /= ntyp .OR. nat_ /= nat ) &
CALL errore('elphon','uncorrect nat or ntyp',1)
CALL read_dyn_mat_header(ntyp, nat, ibrav_, nspin_mag_, &
celldm_, at, bg, omega, atm, amass, tau, ityp, &
m_loc, nqs_)
IF (ibrav_.NE.ibrav .OR. ABS ( celldm_ (1) - celldm (1) ) > 1.0d-5 &
.OR. (nspin_mag_ /= nspin_mag ) ) CALL errore ('elphon', &
'inconsistent data', 1)
CALL read_dyn_mat(nat,1,xq,phip)
!
! Diagonalize the dynamical matrix
!
DO i=1,3
do na=1,nat
nta = ityp (na)
mu=3*(na-1)+i
do j=1,3
do nb=1,nat
nu=3*(nb-1)+j
ntb = ityp (nb)
dyn (mu, nu) = phip (i, j, na, nb) / &
sqrt( amass(nta)*amass(ntb))/amu_ry
enddo
enddo
enddo
enddo
!
CALL cdiagh (3 * nat, dyn, 3 * nat, w2, dyn)
!
! divide by sqrt(mass) to get displacements
!
DO nu = 1, 3 * nat
DO mu = 1, 3 * nat
na = (mu - 1) / 3 + 1
dyn (mu, nu) = dyn (mu, nu) / SQRT ( amu_ry * amass (ityp (na) ) )
ENDDO
ENDDO
CALL read_dyn_mat_tail(nat)
deallocate( phip )
ENDIF
!
! Write phonon frequency to stdout
!
WRITE( stdout, 8000) (xq (i), i = 1, 3)
!
DO nu = 1, 3 * nat
w1 = SQRT( ABS( w2(nu) ) )
if (w2(nu) < 0.d0) w1 = - w1
WRITE( stdout, 8010) nu, w1 * RY_TO_THZ, w1 * RY_TO_CMM1
ENDDO
!
WRITE( stdout, '(1x,74("*"))')
!
ENDIF ! .NOT. trans
!
CALL stop_clock ('elphon')
!
8000 FORMAT(/,5x,'Diagonalizing the dynamical matrix', &
& //,5x,'q = ( ',3f14.9,' ) ',//,1x,74('*'))
8010 FORMAT (5x,'freq (',i5,') =',f15.6,' [THz] =',f15.6,' [cm-1]')
!
RETURN
END SUBROUTINE elphon
!
!-----------------------------------------------------------------------
SUBROUTINE readmat (iudyn, ibrav, celldm, nat, ntyp, ityp, omega, &
amass, tau, q, w2, dyn)
!-----------------------------------------------------------------------
!
USE kinds, ONLY : DP
USE constants, ONLY : amu_ry
IMPLICIT NONE
! Input
INTEGER :: iudyn, ibrav, nat, ntyp, ityp (nat)
REAL(DP) :: celldm (6), amass (ntyp), tau (3, nat), q (3), &
omega
! output
REAL(DP) :: w2 (3 * nat)
COMPLEX(DP) :: dyn (3 * nat, 3 * nat)
! local (control variables)
INTEGER :: ntyp_, nat_, ibrav_, ityp_
REAL(DP) :: celldm_ (6), amass_, tau_ (3), q_ (3)
! local
REAL(DP) :: dynr (2, 3, nat, 3, nat)
CHARACTER(len=80) :: line
CHARACTER(len=3) :: atm
INTEGER :: nt, na, nb, naa, nbb, nu, mu, i, j
!
!
REWIND (iudyn)
READ (iudyn, '(a)') line
READ (iudyn, '(a)') line
READ (iudyn, * ) ntyp_, nat_, ibrav_, celldm_
IF ( ntyp.NE.ntyp_ .OR. nat.NE.nat_ .OR.ibrav_.NE.ibrav .OR. &
ABS ( celldm_ (1) - celldm (1) ) > 1.0d-5) &
CALL errore ('readmat', 'inconsistent data', 1)
IF ( ibrav_ == 0 ) THEN
READ (iudyn, '(a)') line
READ (iudyn, '(a)') line
READ (iudyn, '(a)') line
READ (iudyn, '(a)') line
END IF
DO nt = 1, ntyp
READ (iudyn, * ) i, atm, amass_
IF ( nt.NE.i .OR. ABS (amass_ - amu_ry*amass (nt) ) > 1.0d-5) &
CALL errore ( 'readmat', 'inconsistent data', 1 + nt)
ENDDO
DO na = 1, nat
READ (iudyn, * ) i, ityp_, tau_
IF (na.NE.i.OR.ityp_.NE.ityp (na) ) CALL errore ('readmat', &
'inconsistent data', 10 + na)
ENDDO
READ (iudyn, '(a)') line
READ (iudyn, '(a)') line
READ (iudyn, '(a)') line
READ (iudyn, '(a)') line
READ (line (11:80), * ) (q_ (i), i = 1, 3)
READ (iudyn, '(a)') line
DO na = 1, nat
DO nb = 1, nat
READ (iudyn, * ) naa, nbb
IF (na.NE.naa.OR.nb.NE.nbb) CALL errore ('readmat', 'error reading &
&file', nb)
READ (iudyn, * ) ( (dynr (1, i, na, j, nb), dynr (2, i, na, j, nb) &
, j = 1, 3), i = 1, 3)
ENDDO
ENDDO
!
! divide the dynamical matrix by the (input) masses (in amu)
!
DO nb = 1, nat
DO j = 1, 3
DO na = 1, nat
DO i = 1, 3
dynr (1, i, na, j, nb) = dynr (1, i, na, j, nb) / SQRT (amass ( &
ityp (na) ) * amass (ityp (nb) ) ) / amu_ry
dynr (2, i, na, j, nb) = dynr (2, i, na, j, nb) / SQRT (amass ( &
ityp (na) ) * amass (ityp (nb) ) ) / amu_ry
ENDDO
ENDDO
ENDDO
ENDDO
!
! solve the eigenvalue problem.
! NOTA BENE: eigenvectors are overwritten on dyn
!
CALL cdiagh (3 * nat, dynr, 3 * nat, w2, dyn)
!
! divide by sqrt(mass) to get displacements
!
DO nu = 1, 3 * nat
DO mu = 1, 3 * nat
na = (mu - 1) / 3 + 1
dyn (mu, nu) = dyn (mu, nu) / SQRT ( amu_ry * amass (ityp (na) ) )
ENDDO
ENDDO
!
!
RETURN
END SUBROUTINE readmat
!
!-----------------------------------------------------------------------
SUBROUTINE elphel (irr, npe, imode0, dvscfins)
!-----------------------------------------------------------------------
!
! Calculation of the electron-phonon matrix elements el_ph_mat
! <\psi(k+q)|dV_{SCF}/du^q_{i a}|\psi(k)>
! Original routine written by Francesco Mauri
! Modified by A. Floris and I. Timrov to include Hubbard U (01.10.2018)
!
USE kinds, ONLY : DP
USE fft_base, ONLY : dffts
USE ions_base, ONLY : nat, ityp
USE control_flags, ONLY : iverbosity
USE wavefunctions, ONLY : evc
USE buffers, ONLY : get_buffer
USE klist, ONLY : xk, ngk, igk_k
USE lsda_mod, ONLY : lsda, current_spin, isk, nspin
USE noncollin_module, ONLY : noncolin, npol, nspin_mag
USE wvfct, ONLY : nbnd, npwx
USE buffers, ONLY : get_buffer
USE uspp, ONLY : vkb
USE el_phon, ONLY : el_ph_mat, el_ph_mat_rec, el_ph_mat_rec_col, &
comp_elph, done_elph, elph_nbnd_min, elph_nbnd_max
USE modes, ONLY : u, nmodes
USE units_ph, ONLY : iubar, lrbar, iundnsscf
USE units_lr, ONLY : iuwfc, lrwfc
USE control_ph, ONLY : trans, current_iq
USE ph_restart, ONLY : ph_writefile
USE spin_orb, ONLY : domag
USE mp_bands, ONLY : intra_bgrp_comm, ntask_groups
USE mp_pools, ONLY : npool
USE mp, ONLY : mp_sum, mp_bcast
USE mp_world, ONLY : world_comm
USE elph_tetra_mod, ONLY : elph_tetra
USE eqv, ONLY : dvpsi, evq
USE qpoint, ONLY : nksq, ikks, ikqs, nksqtot
USE control_lr, ONLY : lgamma
USE fft_helper_subroutines
USE ldaU, ONLY : lda_plus_u, Hubbard_lmax
USE ldaU_ph, ONLY : dnsscf_all_modes, dnsscf
USE io_global, ONLY : ionode, ionode_id
USE lrus, ONLY : becp1
USE phus, ONLY : alphap
IMPLICIT NONE
!
INTEGER, INTENT(IN) :: irr, npe, imode0
COMPLEX(DP), INTENT(IN) :: dvscfins (dffts%nnr, nspin_mag, npe)
! LOCAL variables
INTEGER :: npw, npwq, nrec, ik, ikk, ikq, ipert, mode, ibnd, jbnd, ir, ig, &
ipol, ios, ierr
COMPLEX(DP) , ALLOCATABLE :: aux1 (:,:), elphmat (:,:,:), tg_dv(:,:), &
tg_psic(:,:), aux2(:,:)
INTEGER :: v_siz, incr
COMPLEX(DP), EXTERNAL :: zdotc
integer :: ibnd_fst, ibnd_lst
!
if(elph_tetra == 0) then
ibnd_fst = 1
ibnd_lst = nbnd
else
ibnd_fst = elph_nbnd_min
ibnd_lst = elph_nbnd_max
end if
!
IF (.NOT. comp_elph(irr) .OR. done_elph(irr)) RETURN
ALLOCATE (aux1 (dffts%nnr, npol))
ALLOCATE (elphmat ( nbnd , nbnd , npe))
ALLOCATE( el_ph_mat_rec (nbnd,nbnd,nksq,npe) )
el_ph_mat_rec=(0.0_DP,0.0_DP)
ALLOCATE (aux2(npwx*npol, nbnd))
incr=1
IF ( dffts%has_task_groups ) THEN
!
v_siz = dffts%nnr_tg
ALLOCATE( tg_dv ( v_siz, nspin_mag ) )
ALLOCATE( tg_psic( v_siz, npol ) )
incr = fftx_ntgrp(dffts)
!
ENDIF
!
! DFPT+U case
!
IF (lda_plus_u) THEN
!
! Allocate and re-read dnsscf_all_modes from file
!
ALLOCATE (dnsscf_all_modes(2*Hubbard_lmax+1, 2*Hubbard_lmax+1, nspin, nat, nmodes))
dnsscf_all_modes = (0.d0, 0.d0)
IF (ionode) READ(iundnsscf,*) dnsscf_all_modes
CALL mp_bcast(dnsscf_all_modes, ionode_id, world_comm)
REWIND(iundnsscf)
!
! Check whether the re-read is correct
!
IF (iverbosity==1) CALL elphel_read_dnsscf_check()
!
! Allocate dnsscf
!
ALLOCATE (dnsscf(2*Hubbard_lmax+1, 2*Hubbard_lmax+1, nspin, nat, npe))
dnsscf = (0.d0, 0.d0)
!
ENDIF
!
! Start the loops over the k-points
!
DO ik = 1, nksq
!
! ik = counter of k-points with vector k
! ikk= index of k-point with vector k
! ikq= index of k-point with vector k+q
! k and k+q are alternated if q!=0, are the same if q=0
!
ikk = ikks(ik)
ikq = ikqs(ik)
IF (lsda) current_spin = isk (ikk)
npw = ngk(ikk)
npwq= ngk(ikq)
!
CALL init_us_2 (npwq, igk_k(1,ikq), xk (1, ikq), vkb)
!
! read unperturbed wavefuctions psi(k) and psi(k+q)
!
IF (nksq.GT.1) THEN
IF (lgamma) THEN
CALL get_buffer(evc, lrwfc, iuwfc, ikk)
ELSE
CALL get_buffer (evc, lrwfc, iuwfc, ikk)
CALL get_buffer (evq, lrwfc, iuwfc, ikq)
ENDIF
ENDIF
!
DO ipert = 1, npe
nrec = (ipert - 1) * nksq + ik
!
! dvbare_q*psi_kpoint is read from file (if available) or recalculated
!
IF (trans) THEN
CALL get_buffer (dvpsi, lrbar, iubar, nrec)
ELSE
mode = imode0 + ipert
! FIXME: .false. or .true. ???
CALL dvqpsi_us (ik, u (1, mode), .FALSE., becp1, alphap)
!
! DFPT+U: calculate the bare derivative of the Hubbard potential in el-ph
!
IF (lda_plus_u) CALL dvqhub_barepsi_us (ik, u(1,mode))
!
ENDIF
!
! calculate dvscf_q*psi_k
!
IF ( dffts%has_task_groups ) THEN
IF (noncolin) THEN
CALL tg_cgather( dffts, dvscfins(:,1,ipert), tg_dv(:,1))
IF (domag) THEN
DO ipol=2,4
CALL tg_cgather( dffts, dvscfins(:,ipol,ipert), tg_dv(:,ipol))
ENDDO
ENDIF
ELSE
CALL tg_cgather( dffts, dvscfins(:,current_spin,ipert), tg_dv(:,1))
ENDIF
ENDIF
aux2=(0.0_DP,0.0_DP)
DO ibnd = ibnd_fst, ibnd_lst, incr
IF ( dffts%has_task_groups ) THEN
CALL cft_wave_tg (ik, evc, tg_psic, 1, v_siz, ibnd, nbnd )
CALL apply_dpot(v_siz, tg_psic, tg_dv, 1)
CALL cft_wave_tg (ik, aux2, tg_psic, -1, v_siz, ibnd, nbnd)
ELSE
CALL cft_wave (ik, evc(1, ibnd), aux1, +1)
CALL apply_dpot(dffts%nnr, aux1, dvscfins(1,1,ipert), current_spin)
CALL cft_wave (ik, aux2(1, ibnd), aux1, -1)
ENDIF
ENDDO
dvpsi=dvpsi+aux2
!
CALL adddvscf (ipert, ik)
!
! DFPT+U: add to dvpsi the scf part of the perturbed Hubbard potential
!
IF (lda_plus_u) THEN
dnsscf(:,:,:,:,ipert) = dnsscf_all_modes(:,:,:,:,mode)
CALL adddvhubscf (ipert, ik)
ENDIF
!
! calculate elphmat(j,i)=<psi_{k+q,j}|dvscf_q*psi_{k,i}> for this pertur
!
DO ibnd = ibnd_fst, ibnd_lst
DO jbnd = ibnd_fst, ibnd_lst
elphmat (jbnd, ibnd, ipert) = zdotc (npwq, evq (1, jbnd), 1, &
dvpsi (1, ibnd), 1)
IF (noncolin) &
elphmat (jbnd, ibnd, ipert) = elphmat (jbnd, ibnd, ipert)+ &
zdotc (npwq, evq(npwx+1,jbnd),1,dvpsi(npwx+1,ibnd), 1)
ENDDO
ENDDO
ENDDO
!
CALL mp_sum (elphmat, intra_bgrp_comm)
!
! save all e-ph matrix elements into el_ph_mat
!
DO ipert = 1, npe
DO jbnd = ibnd_fst, ibnd_lst
DO ibnd = ibnd_fst, ibnd_lst
el_ph_mat (ibnd, jbnd, ik, ipert + imode0) = elphmat (ibnd, jbnd, ipert)
el_ph_mat_rec (ibnd, jbnd, ik, ipert ) = elphmat (ibnd, jbnd, ipert)
ENDDO
ENDDO
ENDDO
ENDDO
!
done_elph(irr)=.TRUE.
if(elph_tetra == 0) then
IF (npool>1) THEN
ALLOCATE(el_ph_mat_rec_col(nbnd,nbnd,nksqtot,npe))
CALL el_ph_collect(npe,el_ph_mat_rec,el_ph_mat_rec_col,nksqtot,nksq)
ELSE
el_ph_mat_rec_col => el_ph_mat_rec
ENDIF
CALL ph_writefile('el_phon',current_iq,irr,ierr)
IF (npool > 1) DEALLOCATE(el_ph_mat_rec_col)
end if
DEALLOCATE(el_ph_mat_rec)
!
DEALLOCATE (elphmat)
DEALLOCATE (aux1)
DEALLOCATE (aux2)
IF ( dffts%has_task_groups ) THEN
DEALLOCATE( tg_dv )
DEALLOCATE( tg_psic )
ENDIF
!
IF (lda_plus_u) THEN
DEALLOCATE (dnsscf_all_modes)
DEALLOCATE (dnsscf)
ENDIF
!
RETURN
!
END SUBROUTINE elphel
!
!------------------------------------------------------------------------
SUBROUTINE elphel_read_dnsscf_check()
!
! DFPT+U: This subroutine checks whether dnsscf_all_modes was
! read correctly from file.
!
USE kinds, ONLY : DP
USE ions_base, ONLY : nat, ityp
USE modes, ONLY : u, nmodes
USE lsda_mod, ONLY : nspin
USE ldaU, ONLY : Hubbard_l, is_hubbard, Hubbard_lmax
USE ldaU_ph, ONLY : dnsscf_all_modes
USE io_global, ONLY : stdout
!
IMPLICIT NONE
!
COMPLEX(DP), ALLOCATABLE :: dnsscf_all_modes_cart(:,:,:,:,:)
INTEGER :: na_icart, nah, is, m1, m2, na, icart, nt, na_icar, imode
!
ALLOCATE(dnsscf_all_modes_cart (2*Hubbard_lmax+1, 2*Hubbard_lmax+1, nspin, nat, nmodes))
dnsscf_all_modes_cart = (0.d0, 0.d0)
!
! Transform dnsscf_all_modes from pattern to cartesian coordinates
!
DO na_icart = 1, 3*nat
DO imode = 1, nmodes
DO nah = 1, nat
nt = ityp(nah)
IF (is_hubbard(nt)) THEN
DO is = 1, nspin
DO m1 = 1, 2*Hubbard_l(nt) + 1
DO m2 = 1, 2*Hubbard_l(nt) + 1
!
dnsscf_all_modes_cart (m1, m2, is, nah, na_icart) = &
dnsscf_all_modes_cart (m1, m2, is, nah, na_icart) + &
dnsscf_all_modes (m1, m2, is, nah, imode) * &
CONJG(u(na_icart,imode))
!
ENDDO
ENDDO
ENDDO
ENDIF
ENDDO
ENDDO
ENDDO
!
! Write dnsscf in cartesian coordinates
!
WRITE(stdout,*)
WRITE(stdout,*) 'DNS_SCF SYMMETRIZED IN CARTESIAN COORDINATES'
!
DO na = 1, nat
DO icart = 1, 3
WRITE( stdout,'(a,1x,i2,2x,a,1x,i2)') 'displaced atom L =', na, 'ipol=', icart
na_icart = 3*(na-1) + icart
DO nah = 1, nat
nt = ityp(nah)
IF (is_hubbard(nt)) THEN
DO is = 1, nspin
WRITE(stdout,'(a,1x,i2,2x,a,1x,i2)') ' Hubbard atom', nah, 'spin', is
DO m1 = 1, 2*Hubbard_l(nt) + 1
WRITE(stdout,'(14(f15.10,1x))') dnsscf_all_modes_cart (m1,:,is,nah,na_icart)
ENDDO
ENDDO
ENDIF
ENDDO
ENDDO
ENDDO
WRITE(stdout,*)
!
DEALLOCATE(dnsscf_all_modes_cart)
!
RETURN
!
END SUBROUTINE elphel_read_dnsscf_check
!------------------------------------------------------------------------
!------------------------------------------------------------------------
SUBROUTINE elphsum ( )
!-----------------------------------------------------------------------
!
! Sum over BZ of the electron-phonon matrix elements el_ph_mat
! Original routine written by Francesco Mauri, modified by PG
! New version by Malgorzata Wierzbowska
!
USE kinds, ONLY : DP
USE constants, ONLY : pi, rytoev, ry_to_cmm1, ry_to_ghz, degspin
USE ions_base, ONLY : nat, ityp, tau
USE cell_base, ONLY : at, bg
USE lsda_mod, ONLY: isk, nspin
USE klist, ONLY: nks, nkstot, xk, wk, nelec
USE start_k, ONLY: nk1, nk2, nk3
USE symm_base, ONLY: s, irt, nsym, invs
USE noncollin_module, ONLY: nspin_lsda, nspin_mag
USE wvfct, ONLY: nbnd, et
USE parameters, ONLY : npk
USE el_phon, ONLY : el_ph_mat, done_elph, el_ph_nsigma, el_ph_ngauss, &
el_ph_sigma
USE modes, ONLY : u, nirr
USE dynmat, ONLY : dyn, w2
USE io_global, ONLY : stdout, ionode, ionode_id
USE mp_pools, ONLY : my_pool_id, npool, kunit
USE mp_images, ONLY : intra_image_comm
USE mp, ONLY : mp_bcast
USE control_ph, ONLY : tmp_dir_phq, xmldyn, current_iq
USE save_ph, ONLY : tmp_dir_save
USE io_files, ONLY : prefix, tmp_dir, seqopn, create_directory
!
USE lr_symm_base, ONLY : minus_q, nsymq, rtau
USE qpoint, ONLY : xq, nksq
USE control_lr, ONLY : lgamma
!
IMPLICIT NONE
! epsw = 20 cm^-1, in Ry
REAL(DP), PARAMETER :: epsw = 20.d0 / ry_to_cmm1
REAL(DP), PARAMETER :: eps = 1.0d-6
!
INTEGER :: iuna2Fsave = 40
!
REAL(DP), allocatable :: gam(:,:), lamb(:,:)
!
! Quantities ending with "fit" are relative to the "dense" grid
!
REAL(DP), allocatable :: xkfit(:,:)
REAL(DP), allocatable, target :: etfit(:,:), wkfit(:)
INTEGER :: nksfit, nk1fit, nk2fit, nk3fit, nkfit, nksfit_real
INTEGER, allocatable :: eqkfit(:), eqqfit(:), sfit(:)
!
integer :: nq, isq (48), imq
! nq : degeneracy of the star of q
! isq: index of q in the star of a given sym.op.
! imq: index of -q in the star of q (0 if not present)
real(DP) :: sxq (3, 48)
! list of vectors in the star of q
!
! workspace used for symmetrisation
!
COMPLEX(DP), allocatable :: g1(:,:,:), g2(:,:,:), g0(:,:), gf(:,:,:)
COMPLEX(DP), allocatable :: point(:), noint(:)
COMPLEX(DP) :: dyn22(3*nat,3*nat), ctemp
!
INTEGER :: ik, ikk, ikq, isig, ibnd, jbnd, ipert, jpert, nu, mu, &
vu, ngauss1, iuelph, ios, i,k,j, ii, jj
INTEGER :: nkBZ, nti, ntj, ntk, nkr, itemp1, itemp2, nn, &
qx,qy,qz,iq,jq,kq
INTEGER, ALLOCATABLE :: eqBZ(:), sBZ(:)
REAL(DP) :: weight, wqa, w0g1, w0g2, degauss1, effit1, dosef, &
ef1, lambda, gamma
REAL(DP), ALLOCATABLE :: deg(:), effit(:), dosfit(:)
REAL(DP) :: etk, etq
REAL(DP), EXTERNAL :: dos_ef, efermig, w0gauss
character(len=80) :: name
LOGICAL :: exst, xmldyn_save
!
COMPLEX(DP) :: el_ph_sum (3*nat,3*nat)
COMPLEX(DP), POINTER :: el_ph_mat_collect(:,:,:,:)
REAL(DP), ALLOCATABLE :: xk_collect(:,:)
REAL(DP), POINTER :: wkfit_dist(:), etfit_dist(:,:)
INTEGER :: nksfit_dist, rest, kunit_save
INTEGER :: nks_real, ispin, nksqtot, irr
CHARACTER(LEN=256) :: elph_dir
CHARACTER(LEN=6) :: int_to_char
!
!
!
! If the electron phonon matrix elements have not been calculated for
! all representations this routine exit
!
DO irr=1,nirr
IF (.NOT.done_elph(irr)) RETURN
ENDDO
elph_dir='elph_dir/'
IF (ionode) INQUIRE(file=TRIM(elph_dir), EXIST=exst)
CALL mp_bcast(exst, ionode_id, intra_image_comm)
IF (.NOT.exst) CALL create_directory( elph_dir )
WRITE (6, '(5x,"electron-phonon interaction ..."/)')
ngauss1 = 0
ALLOCATE(xk_collect(3,nkstot))
ALLOCATE(deg(el_ph_nsigma))
ALLOCATE(effit(el_ph_nsigma))
ALLOCATE(dosfit(el_ph_nsigma))
IF (npool==1) THEN
!
! no pool, just copy old variables on the new ones
!
nksqtot=nksq
xk_collect(:,1:nks) = xk(:,1:nks)
el_ph_mat_collect => el_ph_mat
ELSE
!
! pools, allocate new variables and collect the results. All the rest
! remain unchanged.
!
IF (lgamma) THEN
nksqtot=nkstot
ELSE
nksqtot=nkstot/2
ENDIF
CALL poolcollect(3, nks, xk, nkstot, xk_collect)
ALLOCATE(el_ph_mat_collect(nbnd,nbnd,nksqtot,3*nat))
! FIXME: this routine should be replaced by a generic routine
CALL el_ph_collect(3*nat,el_ph_mat,el_ph_mat_collect,nksqtot,nksq)
ENDIF
!
! read eigenvalues for the dense grid
! FIXME: this should be done from the xml file, not from a specialized file
! parallel case: only first node reads
!
IF ( ionode ) THEN
tmp_dir=tmp_dir_save
CALL seqopn( iuna2Fsave, 'a2Fsave', 'FORMATTED', exst )
tmp_dir=tmp_dir_phq
READ(iuna2Fsave,*) ibnd, nksfit
END IF
!
CALL mp_bcast (ibnd, ionode_id, intra_image_comm)
CALL mp_bcast (nksfit, ionode_id, intra_image_comm)
if ( ibnd /= nbnd ) call errore('elphsum','wrong file read',iuna2Fsave)
allocate (etfit(nbnd,nksfit), xkfit(3,nksfit), wkfit(nksfit))
!
IF ( ionode ) THEN
READ(iuna2Fsave,*) etfit
READ(iuna2Fsave,*) ((xkfit(i,ik), i=1,3), ik=1,nksfit)
READ(iuna2Fsave,*) wkfit
READ(iuna2Fsave,*) nk1fit, nk2fit, nk3fit
CLOSE( UNIT = iuna2Fsave, STATUS = 'KEEP' )
END IF
!
! broadcast all variables read
!
CALL mp_bcast (etfit, ionode_id, intra_image_comm)
CALL mp_bcast (xkfit, ionode_id, intra_image_comm)
CALL mp_bcast (wkfit, ionode_id, intra_image_comm)
CALL mp_bcast (nk1fit, ionode_id, intra_image_comm)
CALL mp_bcast (nk2fit, ionode_id, intra_image_comm)
CALL mp_bcast (nk3fit, ionode_id, intra_image_comm)
!
nkfit=nk1fit*nk2fit*nk3fit
!
! efermig and dos_ef require scattered points and eigenvalues
! isk is neither read nor used. phonon with two Fermi energies is
! not yet implemented.
!
nksfit_dist = ( nksfit / npool )
rest = ( nksfit - nksfit_dist * npool )
IF ( ( my_pool_id + 1 ) <= rest ) nksfit_dist = nksfit_dist + 1
kunit_save=kunit
kunit=1
#if defined(__MPI)
ALLOCATE(etfit_dist(nbnd,nksfit_dist))
ALLOCATE(wkfit_dist(nksfit_dist))
CALL poolscatter( 1, nksfit, wkfit, nksfit_dist, wkfit_dist )
CALL poolscatter( nbnd, nksfit, etfit, nksfit_dist, etfit_dist )
#else
wkfit_dist => wkfit
etfit_dist => etfit
#endif
!
do isig=1,el_ph_nsigma
!
! recalculate Ef = effit and DOS at Ef N(Ef) = dosfit using dense grid
! for value "deg" of gaussian broadening
!
deg(isig) = isig * el_ph_sigma
!
effit(isig) = efermig &
( etfit_dist, nbnd, nksfit_dist, nelec, wkfit_dist, &
deg(isig), ngauss1, 0, isk)
dosfit(isig) = dos_ef ( ngauss1, deg(isig), effit(isig), etfit_dist, &
wkfit_dist, nksfit_dist, nbnd) / 2.0d0
enddo
#if defined(__MPI)
DEALLOCATE(etfit_dist)
DEALLOCATE(wkfit_dist)
#endif
kunit=kunit_save
allocate (eqkfit(nkfit), eqqfit(nkfit), sfit(nkfit))
!
! map k-points in the IBZ to k-points in the complete uniform grid
!
nksfit_real=nksfit/nspin_lsda
call lint ( nsym, s, .true., at, bg, npk, 0,0,0, &
nk1fit,nk2fit,nk3fit, nksfit_real, xkfit, 1, nkfit, eqkfit, sfit)
deallocate (sfit, xkfit, wkfit)
!
! find epsilon(k+q) in the dense grid
!
call cryst_to_cart (1, xq, at, -1)
qx = nint(nk1fit*xq(1))
if (abs(qx-nk1fit*xq(1)) > eps) &
call errore('elphsum','q is not a vector in the dense grid',1)
if (qx < 0) qx = qx + nk1fit
if (qx > nk1fit) qx = qx - nk1fit
qy = nint(nk2fit*xq(2))
if (abs(qy-nk2fit*xq(2)) > eps) &
call errore('elphsum','q is not a vector in the dense grid',2)
if (qy < 0) qy = qy + nk2fit
if (qy > nk2fit) qy = qy - nk2fit
qz = nint(nk3fit*xq(3))
if (abs(qz-nk3fit*xq(3)) > eps) &
call errore('elphsum','q is not a vector in the dense grid',3)
if (qz < 0) qz = qz + nk3fit
if (qz > nk3fit) qz = qz - nk3fit
call cryst_to_cart (1, xq, bg, 1)
!
eqqfit(:) = 0
do i=1,nk1fit
do j=1,nk2fit
do k=1,nk3fit
ik = k-1 + (j-1)*nk3fit + (i-1)*nk2fit*nk3fit + 1
iq = i+qx
if (iq > nk1fit) iq = iq - nk1fit
jq = j+qy
if (jq > nk2fit) jq = jq - nk2fit
kq = k+qz
if (kq > nk3fit) kq = kq - nk3fit
nn = (kq-1)+(jq-1)*nk3fit+(iq-1)*nk2fit*nk3fit + 1
eqqfit(ik) = eqkfit(nn)
enddo
enddo
enddo
!
! calculate the electron-phonon coefficient using the dense grid
!
nti = nk1fit/nk1
ntj = nk2fit/nk2
ntk = nk3fit/nk3
nkBZ = nk1*nk2*nk3
allocate (eqBZ(nkBZ), sBZ(nkBZ))
!
nks_real=nkstot/nspin_lsda
IF ( lgamma ) THEN
call lint ( nsymq, s, minus_q, at, bg, npk, 0,0,0, &
nk1,nk2,nk3, nks_real, xk_collect, 1, nkBZ, eqBZ, sBZ)
ELSE
call lint ( nsymq, s, minus_q, at, bg, npk, 0,0,0, &
nk1,nk2,nk3, nks_real, xk_collect, 2, nkBZ, eqBZ, sBZ)
END IF
!
allocate (gf(3*nat,3*nat,el_ph_nsigma))
gf = (0.0d0,0.0d0)
!
wqa = 1.0d0/nkfit
IF (nspin==1) wqa=degspin*wqa
!
do ibnd = 1, nbnd
do jbnd = 1, nbnd
allocate (g2(nkBZ*nspin_lsda,3*nat,3*nat))
allocate (g1(nksqtot,3*nat,3*nat))
do ik = 1, nksqtot
do ii = 1, 3*nat
do jj = 1, 3*nat
g1(ik,ii,jj)=CONJG(el_ph_mat_collect(jbnd,ibnd,ik,ii))* &
el_ph_mat_collect(jbnd,ibnd,ik,jj)
enddo ! ipert
enddo !jpert
enddo ! ik
!
allocate (g0(3*nat,3*nat))
do i=1,nk1
do j=1,nk2
do k=1,nk3
do ispin=1,nspin_lsda
nn = k-1 + (j-1)*nk3 + (i-1)*nk2*nk3 + 1
itemp1 = eqBZ(nn)
if (ispin==2) itemp1=itemp1+nksqtot/2
g0(:,:) = g1(itemp1,:,:)
itemp2 = sBZ(nn)
call symm ( g0, u, xq, s, itemp2, rtau, irt, &
at, bg, nat)
if (ispin==2) nn=nn+nkBZ
g2(nn,:,:) = g0(:,:)
enddo
enddo ! k
enddo !j
enddo !i
deallocate (g0)
deallocate (g1)
!
allocate ( point(nkBZ), noint(nkfit) )
do jpert = 1, 3 * nat
do ipert = 1, 3 * nat
do ispin=1,nspin_lsda
!
point(1:nkBZ) = &
g2(1+nkBZ*(ispin-1):nkBZ+nkBZ*(ispin-1),ipert,jpert)
!
CALL clinear(nk1,nk2,nk3,nti,ntj,ntk,point,noint)
!
do isig = 1,el_ph_nsigma
degauss1 = deg(isig)
effit1 = effit(isig)
ctemp = 0
do ik=1,nkfit
etk = etfit(ibnd,eqkfit(ik)+nksfit*(ispin-1)/2)
etq = etfit(jbnd,eqqfit(ik)+nksfit*(ispin-1)/2)
ctemp = ctemp &
+ exp(-((effit1-etk)**2 + (effit1-etq)**2)/degauss1**2)*noint(ik)
enddo
gf(ipert,jpert,isig) = gf(ipert,jpert,isig) + &
ctemp * wqa / (degauss1**2) / pi
enddo ! isig
enddo ! ispin
enddo ! ipert
enddo !jpert
deallocate (point, noint)
deallocate (g2)
!
enddo ! ibnd
enddo ! jbnd
deallocate (eqqfit, eqkfit)
deallocate (etfit)
deallocate (eqBZ, sBZ)
!
allocate (gam(3*nat,el_ph_nsigma), lamb(3*nat,el_ph_nsigma))
lamb(:,:) = 0.0d0
gam (:,:) = 0.0d0
do isig= 1, el_ph_nsigma
do nu = 1,3*nat
gam(nu,isig) = 0.0d0
do mu = 1, 3 * nat
do vu = 1, 3 * nat
gam(nu,isig) = gam(nu,isig) + DBLE(conjg(dyn(mu,nu)) * &
gf(mu,vu,isig) * dyn(vu,nu))
enddo
enddo
gam(nu,isig) = gam(nu,isig) * pi/2.0d0
!
! the factor 2 comes from the factor sqrt(hbar/2/M/omega) that appears
! in the definition of the electron-phonon matrix element g
! The sqrt(1/M) factor is actually hidden into the normal modes
!
! gamma = \pi \sum_k\sum_{i,j} \delta(e_{k,i}-Ef) \delta(e_{k+q,j}-Ef)
! | \sum_mu z(mu,nu) <psi_{k+q,j}|dvscf_q(mu)*psi_{k,i}> |^2
! where z(mu,nu) is the mu component of normal mode nu (z = dyn)
! gamma(nu) is the phonon linewidth of mode nu
!
! The factor N(Ef)^2 that appears in most formulations of el-ph interact
! is absent because we sum, not average, over the Fermi surface.
! The factor 2 is provided by the sum over spins
!
if (sqrt(abs(w2(nu))) > epsw) then
! lambda is the adimensional el-ph coupling for mode nu:
! lambda(nu)= gamma(nu)/(pi N(Ef) \omega_{q,nu}^2)
lamb(nu,isig) = gam(nu,isig)/pi/w2(nu)/dosfit(isig)
else
lamb(nu,isig) = 0.0d0
endif
gam(nu,isig) = gam(nu,isig)*ry_to_ghz
enddo !nu
enddo ! isig
!
do isig= 1,el_ph_nsigma
WRITE (6, 9000) deg(isig), ngauss1
WRITE (6, 9005) dosfit(isig), effit(isig) * rytoev
do nu=1,3*nat
WRITE (6, 9010) nu, lamb(nu,isig), gam(nu,isig)
enddo
enddo
! Isaev: save files in suitable format for processing by lambda.x
name=TRIM(elph_dir)// 'elph.inp_lambda.' //TRIM(int_to_char(current_iq))
IF (ionode) THEN
open(unit=12, file=TRIM(name), form='formatted', status='unknown', &
iostat=ios)
write(12, "(5x,3f14.6,2i6)") xq(1),xq(2),xq(3), el_ph_nsigma, 3*nat
write(12, "(6e14.6)") (w2(i), i=1,3*nat)
do isig= 1, el_ph_nsigma
WRITE (12, 9000) deg(isig), ngauss1
WRITE (12, 9005) dosfit(isig), effit(isig) * rytoev
do nu=1,3*nat
WRITE (12, 9010) nu, lamb(nu,isig), gam(nu,isig)
enddo
enddo
close (unit=12,status='keep')
ENDIF
! Isaev end
CALL mp_bcast(ios, ionode_id, intra_image_comm)
IF (ios /= 0) CALL errore('elphsum','problem opening file'//TRIM(name),1)
deallocate (gam)
deallocate (lamb)
write(stdout,*)
!
! Prepare interface to q2r and matdyn
!
call star_q (xq, at, bg, nsym, s, invs, nq, sxq, isq, imq, .TRUE. )
!
do isig=1,el_ph_nsigma
name=TRIM(elph_dir)//'a2Fq2r.'// TRIM(int_to_char(50 + isig)) &
//'.'//TRIM(int_to_char(current_iq))
if (ionode) then
iuelph = 4
open(iuelph, file=name, STATUS = 'unknown', FORM = 'formatted', &
iostat=ios)
else
!
! this node doesn't write: unit 6 is redirected to /dev/null
!
iuelph =6
end if
call mp_bcast(ios, ionode_id, intra_image_comm)
IF (ios /= 0) call errore('elphsum','opening output file '// TRIM(name),1)
dyn22(:,:) = gf(:,:,isig)
write(iuelph,*) deg(isig), effit(isig), dosfit(isig)
IF ( imq == 0 ) THEN
write(iuelph,*) 2*nq
ELSE
write(iuelph,*) nq
ENDIF
xmldyn_save=xmldyn
xmldyn=.FALSE.
call q2qstar_ph (dyn22, at, bg, nat, nsym, s, invs, &
irt, rtau, nq, sxq, isq, imq, iuelph)
xmldyn=xmldyn_save
if (ionode) CLOSE( UNIT = iuelph, STATUS = 'KEEP' )
enddo
deallocate (gf)
DEALLOCATE( deg )
DEALLOCATE( effit )
DEALLOCATE( dosfit )
DEALLOCATE( xk_collect )
IF (npool /= 1) DEALLOCATE(el_ph_mat_collect)
!
9000 FORMAT(5x,'Gaussian Broadening: ',f7.3,' Ry, ngauss=',i4)
9005 FORMAT(5x,'DOS =',f10.6,' states/spin/Ry/Unit Cell at Ef=', &
& f10.6,' eV')
9006 FORMAT(5x,'double delta at Ef =',f10.6)
9010 FORMAT(5x,'lambda(',i5,')=',f8.4,' gamma=',f8.2,' GHz')
!
RETURN
END SUBROUTINE elphsum
!-----------------------------------------------------------------------
SUBROUTINE elphsum_simple
!-----------------------------------------------------------------------
!
! Sum over BZ of the electron-phonon matrix elements el_ph_mat
! Original routine written by Francesco Mauri
! Rewritten by Matteo Calandra
!-----------------------------------------------------------------------
USE kinds, ONLY : DP
USE constants, ONLY : pi, ry_to_cmm1, ry_to_ghz, rytoev
USE ions_base, ONLY : nat
USE cell_base, ONLY : at, bg
USE symm_base, ONLY : s, irt, nsym, invs
USE klist, ONLY : xk, nelec, nks, wk
USE wvfct, ONLY : nbnd, et
USE el_phon, ONLY : el_ph_mat, el_ph_nsigma, el_ph_ngauss, el_ph_sigma
USE mp_pools, ONLY : inter_pool_comm, npool
USE mp_images, ONLY : intra_image_comm
USE output, ONLY : fildyn
USE dynmat, ONLY : dyn, w2
USE modes, ONLY : u, nirr
USE control_ph, only : current_iq, qplot
USE lsda_mod, only : isk
USE el_phon, ONLY : done_elph, gamma_disp
USE io_global, ONLY : stdout, ionode, ionode_id
USE mp, ONLY: mp_sum, mp_bcast
USE lr_symm_base, ONLY : rtau, nsymq, irotmq, minus_q
USE qpoint, ONLY : xq, nksq, ikks, ikqs
!
IMPLICIT NONE
REAL(DP), PARAMETER :: eps = 20_dp/ry_to_cmm1 ! eps = 20 cm^-1, in Ry
!
INTEGER :: ik, ikk, ikq, isig, ibnd, jbnd, ipert, jpert, nu, mu, &
vu, ngauss1, iuelph, ios, irr
INTEGER :: nmodes
REAL(DP) :: weight, w0g1, w0g2, w0gauss, wgauss, degauss1, dosef, &
ef1, phase_space, lambda, gamma
REAL(DP), EXTERNAL :: dos_ef, efermig
character(len=80) :: filelph
CHARACTER(len=256) :: file_elphmat
!
COMPLEX(DP) :: el_ph_sum (3*nat,3*nat), dyn_corr(3*nat,3*nat)
INTEGER, EXTERNAL :: find_free_unit
CHARACTER(LEN=6) :: int_to_char
DO irr=1,nirr
IF (.NOT.done_elph(irr)) RETURN
ENDDO
nmodes=3*nat
filelph=TRIM(fildyn)//'.elph.'//TRIM(int_to_char(current_iq))
! parallel case: only first node writes
IF ( ionode ) THEN
!
iuelph = find_free_unit()
OPEN (unit = iuelph, file = TRIM(filelph), status = 'unknown', err = &
100, iostat = ios)
REWIND (iuelph)
ELSE
iuelph = 0
!
END IF
100 CONTINUE
CALL mp_bcast(ios,ionode_id,intra_image_comm)
CALL errore ('elphsum_simple', 'opening file '//filelph, ABS (ios) )
IF (ionode) THEN
WRITE (iuelph, '(3f15.8,2i8)') xq, el_ph_nsigma, 3 * nat
WRITE (iuelph, '(6e14.6)') (w2 (nu) , nu = 1, nmodes)
ENDIF
ngauss1=0
DO isig = 1, el_ph_nsigma
! degauss1 = 0.01 * isig
degauss1 = el_ph_sigma * isig
el_ph_sum(:,:) = (0.d0, 0.d0)
phase_space = 0.d0
!
! Recalculate the Fermi energy Ef=ef1 and the DOS at Ef, dosef = N(Ef)
! for this gaussian broadening
!
! Note that the weights of k+q points must be set to zero for the
! following call to yield correct results
!
ef1 = efermig (et, nbnd, nks, nelec, wk, degauss1, el_ph_ngauss, 0, isk)
dosef = dos_ef (el_ph_ngauss, degauss1, ef1, et, wk, nks, nbnd)
! N(Ef) is the DOS per spin, not summed over spin
dosef = dosef / 2.d0
!
! Sum over bands with gaussian weights
!
DO ik = 1, nksq
!
! see subroutine elphel for the logic of indices
!
ikk = ikks(ik)
ikq = ikqs(ik)
DO ibnd = 1, nbnd
w0g1 = w0gauss ( (ef1 - et (ibnd, ikk) ) / degauss1, ngauss1) &
/ degauss1
DO jbnd = 1, nbnd
w0g2 = w0gauss ( (ef1 - et (jbnd, ikq) ) / degauss1, ngauss1) &
/ degauss1
! note that wk(ikq)=wk(ikk)
weight = wk (ikk) * w0g1 * w0g2
DO jpert = 1, 3 * nat
DO ipert = 1, 3 * nat
el_ph_sum (ipert, jpert) = el_ph_sum (ipert, jpert) + weight * &
CONJG (el_ph_mat (jbnd, ibnd, ik, ipert) ) * &
el_ph_mat (jbnd, ibnd, ik, jpert)
ENDDO
ENDDO
phase_space = phase_space+weight
ENDDO
ENDDO
ENDDO
! el_ph_sum(mu,nu)=\sum_k\sum_{i,j}[ <psi_{k+q,j}|dvscf_q(mu)*psi_{k,i}>
! x <psi_{k+q,j}|dvscf_q(nu)*psi_{k,i}>
! x \delta(e_{k,i}-Ef) \delta(e_{k+q,j}
!
! collect contributions from all pools (sum over k-points)
!
call mp_sum ( el_ph_sum , inter_pool_comm )
call mp_sum ( phase_space , inter_pool_comm )
!
! symmetrize el_ph_sum(mu,nu) : it transforms as the dynamical matrix
!
CALL symdyn_munu_new (el_ph_sum, u, xq, s, invs, rtau, irt, at, &
bg, nsymq, nat, irotmq, minus_q)
!
WRITE (stdout, *)
WRITE (stdout, 9000) degauss1, ngauss1
WRITE (stdout, 9005) dosef, ef1 * rytoev
WRITE (stdout, 9006) phase_space
IF (ionode) THEN
WRITE (iuelph, 9000) degauss1, ngauss1
WRITE (iuelph, 9005) dosef, ef1 * rytoev
ENDIF
DO nu = 1, nmodes
gamma = 0.d0
DO mu = 1, 3 * nat
DO vu = 1, 3 * nat
gamma = gamma + DBLE (CONJG (dyn (mu, nu) ) * el_ph_sum (mu, vu)&
* dyn (vu, nu) )
ENDDO
ENDDO
gamma = pi * gamma / 2.d0
!
! the factor 2 comes from the factor sqrt(hbar/2/M/omega) that appears
! in the definition of the electron-phonon matrix element g
! The sqrt(1/M) factor is actually hidden into the normal modes
!
! gamma = \pi \sum_k\sum_{i,j} \delta(e_{k,i}-Ef) \delta(e_{k+q,j}-Ef)
! | \sum_mu z(mu,nu) <psi_{k+q,j}|dvscf_q(mu)*psi_{k,i}> |^2
! where z(mu,nu) is the mu component of normal mode nu (z = dyn)
! gamma(nu) is the phonon linewidth of mode nu
!
! The factor N(Ef)^2 that appears in most formulations of el-ph interact
! is absent because we sum, not average, over the Fermi surface.
! The factor 2 is provided by the sum over spins
!
IF (SQRT (ABS (w2 (nu) ) ) > eps) THEN
! lambda is the adimensional el-ph coupling for mode nu:
! lambda(nu)= gamma(nu)/(pi N(Ef) \omega_{q,nu}^2)
lambda = gamma / pi / w2 (nu) / dosef
ELSE
lambda = 0.d0
ENDIF
WRITE (stdout, 9010) nu, lambda, gamma * ry_to_gHz
IF (ionode) WRITE (iuelph, 9010) nu, lambda, gamma * ry_to_gHz
IF (qplot) gamma_disp(nu,isig,current_iq) = gamma * ry_to_gHz
ENDDO
ENDDO
9000 FORMAT(5x,'Gaussian Broadening: ',f7.3,' Ry, ngauss=',i4)
9005 FORMAT(5x,'DOS =',f10.6,' states/spin/Ry/Unit Cell at Ef=', &
& f10.6,' eV')
9006 FORMAT(5x,'double delta at Ef =',f10.6)
9010 FORMAT(5x,'lambda(',i5,')=',f8.4,' gamma=',f8.2,' GHz')
!
!
IF (ionode) CLOSE (unit = iuelph)
RETURN
! call star_q(x_q(1,iq), at, bg, nsym , s , invs , nq, sxq, &
! isq, imq, .FALSE. )
END SUBROUTINE elphsum_simple
!-----------------------------------------------------------------------
SUBROUTINE elphfil_epa(iq)
!-----------------------------------------------------------------------
!
! Writes electron-phonon matrix elements to a file
! which is subsequently processed by the epa code
! Original routine written by Georgy Samsonidze
!
!-----------------------------------------------------------------------
USE cell_base, ONLY : ibrav, alat, omega, tpiba, at, bg
USE disp, ONLY : nq1, nq2, nq3, nqs, x_q, wq, lgamma_iq
USE dynmat, ONLY : dyn, w2
USE el_phon, ONLY : el_ph_mat, done_elph
USE fft_base, ONLY : dfftp, dffts, dfftb
USE gvect, ONLY : ngm_g, ecutrho
USE io_global, ONLY : ionode, ionode_id
USE ions_base, ONLY : nat, nsp, atm, ityp, tau
USE kinds, ONLY : DP
USE klist, ONLY : xk, wk, nelec, nks, nkstot, ngk
USE lsda_mod, ONLY : nspin, isk
USE modes, ONLY : nirr, nmodes, npert, npertx, u, t, tmq, &
name_rap_mode, num_rap_mode
USE lr_symm_base, ONLY : irgq, nsymq, irotmq, rtau, gi, gimq, &
minus_q, invsymq
USE mp, ONLY : mp_bcast, mp_sum
USE mp_images, ONLY : intra_image_comm
USE mp_pools, ONLY : npool, intra_pool_comm
USE qpoint, ONLY : nksq, nksqtot, ikks, ikqs, eigqts
USE start_k, ONLY : nk1, nk2, nk3, k1, k2, k3
USE symm_base, ONLY : s, invs, ft, nrot, nsym, nsym_ns, &
nsym_na, ft, sr, sname, t_rev, irt, time_reversal, &
invsym, nofrac, allfrac, nosym, nosym_evc, no_t_rev
USE wvfct, ONLY : nbnd, et, wg
USE gvecw, ONLY : ecutwfc
USE io_files, ONLY : prefix
IMPLICIT NONE
INTEGER, INTENT(IN) :: iq
INTEGER :: iuelph, ios, irr, ii, jj, kk, ll
character :: cdate*9, ctime*9, sdate*32, stime*32, &
stitle*32, myaccess*10, mystatus*7
CHARACTER(LEN=80) :: filelph
REAL(DP), ALLOCATABLE :: xk_collect(:,:), wk_collect(:)
REAL(DP), ALLOCATABLE :: et_collect(:,:), wg_collect(:,:)
INTEGER, ALLOCATABLE :: ngk_collect(:)
INTEGER, ALLOCATABLE :: ikks_collect(:), ikqs_collect(:)
COMPLEX(DP), ALLOCATABLE :: el_ph_mat_collect(:,:,:,:)
INTEGER :: ftau(3,48)
INTEGER, EXTERNAL :: find_free_unit, atomic_number
filelph = TRIM(prefix) // '.epa.k'
DO irr = 1, nirr
IF (.NOT. done_elph(irr)) RETURN
ENDDO
IF (iq .EQ. 1) THEN
myaccess = 'sequential'
mystatus = 'replace'
ELSE
myaccess = 'append'
mystatus = 'old'
ENDIF
IF (ionode) THEN
iuelph = find_free_unit()
OPEN(unit = iuelph, file = TRIM(filelph), form = 'unformatted', &
access = myaccess, status = mystatus, iostat = ios)
ELSE
iuelph = 0
ENDIF
CALL mp_bcast(ios, ionode_id, intra_image_comm)
CALL errore('elphfil_epa', 'opening file ' // filelph, ABS(ios))
IF (iq .EQ. 1) THEN
CALL date_and_tim(cdate, ctime)
WRITE(sdate, '(A2,"-",A3,"-",A4,21X)') cdate(1:2), cdate(3:5), cdate(6:9)
WRITE(stime, '(A8,24X)') ctime(1:8)
WRITE(stitle, '("EPA-Complex",21X)')
CALL cryst_to_cart(nqs, x_q, at, -1)
! write header
IF (ionode) THEN
WRITE(iuelph) stitle, sdate, stime
WRITE(iuelph) ibrav, nat, nsp, nrot, nsym, nsym_ns, nsym_na, &
ngm_g, nspin, nbnd, nmodes, nqs
WRITE(iuelph) nq1, nq2, nq3, nk1, nk2, nk3, k1, k2, k3
WRITE(iuelph) time_reversal, invsym, nofrac, allfrac, nosym, &
nosym_evc, no_t_rev
WRITE(iuelph) alat, omega, tpiba, nelec, ecutrho, ecutwfc
WRITE(iuelph) dfftp%nr1, dfftp%nr2, dfftp%nr3
WRITE(iuelph) dffts%nr1, dffts%nr2, dffts%nr3
WRITE(iuelph) dfftb%nr1, dfftb%nr2, dfftb%nr3
WRITE(iuelph) ((at(ii, jj), ii = 1, 3), jj = 1, 3)
WRITE(iuelph) ((bg(ii, jj), ii = 1, 3), jj = 1, 3)
WRITE(iuelph) (atomic_number(atm(ii)), ii = 1, nsp)
WRITE(iuelph) (ityp(ii), ii = 1, nat)
WRITE(iuelph) ((tau(ii, jj), ii = 1, 3), jj = 1, nat)
WRITE(iuelph) ((x_q(ii, jj), ii = 1, 3), jj = 1, nqs)
WRITE(iuelph) (wq(ii), ii = 1, nqs)
WRITE(iuelph) (lgamma_iq(ii), ii = 1, nqs)
ENDIF
CALL cryst_to_cart(nqs, x_q, bg, 1)
ENDIF
! collect data for current q-point
ALLOCATE(xk_collect(3, nkstot))
ALLOCATE(wk_collect(nkstot))
ALLOCATE(et_collect(nbnd, nkstot))
ALLOCATE(wg_collect(nbnd, nkstot))
ALLOCATE(ngk_collect(nkstot))
ALLOCATE(ikks_collect(nksqtot))
ALLOCATE(ikqs_collect(nksqtot))
ALLOCATE(el_ph_mat_collect(nbnd, nbnd, nksqtot, nmodes))
IF (npool > 1) THEN
CALL poolcollect(3, nks, xk, nkstot, xk_collect)
CALL poolcollect(1, nks, wk, nkstot, wk_collect)
CALL poolcollect(nbnd, nks, et, nkstot, et_collect)
CALL poolcollect(nbnd, nks, wg, nkstot, wg_collect)
CALL ipoolcollect(1, nks, ngk, nkstot, ngk_collect)
CALL jpoolcollect(1, nksq, ikks, nksqtot, ikks_collect)
CALL jpoolcollect(1, nksq, ikqs, nksqtot, ikqs_collect)
CALL el_ph_collect(nmodes, el_ph_mat, el_ph_mat_collect, nksqtot, nksq)
ELSE
xk_collect(1:3, 1:nks) = xk(1:3, 1:nks)
wk_collect(1:nks) = wk(1:nks)
et_collect(1:nbnd, 1:nks) = et(1:nbnd, 1:nks)
wg_collect(1:nbnd, 1:nks) = wg(1:nbnd, 1:nks)
ngk_collect(1:nks) = ngk(1:nks)
ikks_collect(1:nksq) = ikks(1:nksq)
ikqs_collect(1:nksq) = ikqs(1:nksq)
el_ph_mat_collect(1:nbnd, 1:nbnd, 1:nksq, 1:nmodes) = &
el_ph_mat(1:nbnd, 1:nbnd, 1:nksq, 1:nmodes)
ENDIF
CALL cryst_to_cart(nkstot, xk_collect, at, -1)
! write data for current q-point
IF (ionode) THEN
WRITE(iuelph) nsymq, irotmq, nirr, npertx, nkstot, nksqtot
WRITE(iuelph) minus_q, invsymq
WRITE(iuelph) (irgq(ii), ii = 1, 48)
WRITE(iuelph) (npert(ii), ii = 1, nmodes)
WRITE(iuelph) (((rtau(ii, jj, kk), ii = 1, 3), jj = 1, 48), &
kk = 1, nat)
WRITE(iuelph) ((gi(ii, jj), ii = 1, 3), jj = 1, 48)
WRITE(iuelph) (gimq(ii), ii = 1, 3)
WRITE(iuelph) ((u(ii, jj), ii = 1, nmodes), jj = 1, nmodes)
WRITE(iuelph) ((((t(ii, jj, kk, ll), ii = 1, npertx), &
jj = 1, npertx), kk = 1, 48), ll = 1, nmodes)
WRITE(iuelph) (((tmq(ii, jj, kk), ii = 1, npertx), &
jj = 1, npertx), kk = 1, nmodes)
WRITE(iuelph) (name_rap_mode(ii), ii = 1, nmodes)
WRITE(iuelph) (num_rap_mode(ii), ii = 1, nmodes)
WRITE(iuelph) (((s(ii, jj, kk), ii = 1, 3), jj = 1, 3), kk = 1, 48)
WRITE(iuelph) (invs(ii), ii = 1, 48)
! FIXME: should disappear
ftau(1,1:48) = NINT(ft(1,1:48)*dfftp%nr1)
ftau(2,1:48) = NINT(ft(2,1:48)*dfftp%nr2)
ftau(3,1:48) = NINT(ft(3,1:48)*dfftp%nr3)
WRITE(iuelph) ((ftau(ii, jj), ii = 1, 3), jj = 1, 48)
! end FIXME
WRITE(iuelph) ((ft(ii, jj), ii = 1, 3), jj = 1, 48)
WRITE(iuelph) (((sr(ii, jj, kk), ii = 1, 3), jj = 1, 3), kk = 1, 48)
WRITE(iuelph) (sname(ii), ii = 1, 48)
WRITE(iuelph) (t_rev(ii), ii = 1, 48)
WRITE(iuelph) ((irt(ii, jj), ii = 1, 48), jj = 1, nat)
WRITE(iuelph) ((xk_collect(ii, jj), ii = 1, 3), jj = 1, nkstot)
WRITE(iuelph) (wk_collect(ii), ii = 1, nkstot)
WRITE(iuelph) ((et_collect(ii, jj), ii = 1, nbnd), jj = 1, nkstot)
WRITE(iuelph) ((wg_collect(ii, jj), ii = 1, nbnd), jj = 1, nkstot)
WRITE(iuelph) (isk(ii), ii = 1, nkstot)
WRITE(iuelph) (ngk_collect(ii), ii = 1, nkstot)
WRITE(iuelph) (ikks_collect(ii), ii = 1, nksqtot)
WRITE(iuelph) (ikqs_collect(ii), ii = 1, nksqtot)
WRITE(iuelph) (eigqts(ii), ii = 1, nat)
WRITE(iuelph) (w2(ii), ii = 1, nmodes)
WRITE(iuelph) ((dyn(ii, jj), ii = 1, nmodes), jj = 1, nmodes)
WRITE(iuelph) ((((el_ph_mat_collect(ii, jj, kk, ll), ii = 1, nbnd), &
jj = 1, nbnd), kk = 1, nksqtot), ll = 1, nmodes)
CLOSE (unit = iuelph, status = 'keep')
ENDIF
CALL cryst_to_cart(nkstot, xk_collect, bg, 1)
DEALLOCATE(xk_collect)
DEALLOCATE(wk_collect)
DEALLOCATE(et_collect)
DEALLOCATE(wg_collect)
DEALLOCATE(ngk_collect)
DEALLOCATE(ikks_collect)
DEALLOCATE(ikqs_collect)
DEALLOCATE(el_ph_mat_collect)
RETURN
END SUBROUTINE elphfil_epa
!----------------------------------------------------------------------------
SUBROUTINE ipoolcollect( length, nks, f_in, nkstot, f_out )
!----------------------------------------------------------------------------
!
! ... as poolcollect, for an integer vector
!
USE mp_pools, ONLY : my_pool_id, npool, kunit, &
inter_pool_comm, intra_pool_comm
USE mp, ONLY : mp_sum
!
IMPLICIT NONE
!
INTEGER, INTENT(IN) :: length, nks, nkstot
! first dimension of arrays
! number of k-points per pool
! total number of k-points
INTEGER, INTENT(IN) :: f_in (length,nks)
! pool-distributed function
INTEGER, INTENT(OUT) :: f_out(length,nkstot)
! pool-collected function
!
INTEGER :: nbase, rest, nks1
!
nks1 = kunit * ( nkstot / kunit / npool )
!
rest = ( nkstot - nks1 * npool ) / kunit
!
IF ( ( my_pool_id + 1 ) <= rest ) nks1 = nks1 + kunit
!
IF (nks1.ne.nks) &
call errore('ipoolcollect','inconsistent number of k-points',1)
!
! ... calculates nbase = the position in the list of the first point that
! ... belong to this npool - 1
!
nbase = nks * my_pool_id
!
IF ( ( my_pool_id + 1 ) > rest ) nbase = nbase + rest * kunit
!
! copy the original points in the correct position of the list
!
f_out=0
f_out(:,nbase+1:nbase+nks) = f_in(:,1:nks)
!
CALL mp_sum( f_out, inter_pool_comm )
!
RETURN
!
END SUBROUTINE ipoolcollect
!----------------------------------------------------------------------------
SUBROUTINE jpoolcollect( length, nks, f_in, nkstot, f_out )
!----------------------------------------------------------------------------
!
! ... as ipoolcollect, without kunit and with an index shift
!
USE mp_pools, ONLY : my_pool_id, npool, kunit, &
inter_pool_comm, intra_pool_comm
USE mp, ONLY : mp_sum
!
IMPLICIT NONE
!
INTEGER, INTENT(IN) :: length, nks, nkstot
! first dimension of arrays
! number of k-points per pool
! total number of k-points
INTEGER, INTENT(IN) :: f_in (length,nks)
! pool-distributed function
INTEGER, INTENT(OUT) :: f_out(length,nkstot)
! pool-collected function
!
INTEGER :: nbase, rest, nks1
!
nks1 = ( nkstot / npool )
!
rest = ( nkstot - nks1 * npool )
!
IF ( ( my_pool_id + 1 ) <= rest ) nks1 = nks1 + 1
!
IF (nks1.ne.nks) &
call errore('jpoolcollect','inconsistent number of k-points',1)
!
! ... calculates nbase = the position in the list of the first point that
! ... belong to this npool - 1
!
nbase = nks * my_pool_id
!
IF ( ( my_pool_id + 1 ) > rest ) nbase = nbase + rest
!
! copy the original points in the correct position of the list
!
f_out=0
f_out(:,nbase+1:nbase+nks) = f_in(:,1:nks) + nbase * kunit
!
CALL mp_sum( f_out, inter_pool_comm )
!
RETURN
!
END SUBROUTINE jpoolcollect
!-----------------------------------------------------------------------
FUNCTION dos_ef (ngauss, degauss, ef, et, wk, nks, nbnd)
!-----------------------------------------------------------------------
!
USE kinds, ONLY : DP
USE mp_pools, ONLY : inter_pool_comm
USE mp, ONLY : mp_sum
IMPLICIT NONE
REAL(DP) :: dos_ef
INTEGER :: ngauss, nbnd, nks
REAL(DP) :: et (nbnd, nks), wk (nks), ef, degauss
!
INTEGER :: ik, ibnd
REAL(DP), EXTERNAL :: w0gauss
!
! Compute DOS at E_F (states per Ry per unit cell)
!
dos_ef = 0.0d0
DO ik = 1, nks
DO ibnd = 1, nbnd
dos_ef = dos_ef + wk (ik) * w0gauss ( (et (ibnd, ik) - ef) &
/ degauss, ngauss) / degauss
ENDDO
ENDDO
!
! Collects partial sums on k-points from all pools
!
CALL mp_sum ( dos_ef, inter_pool_comm )
!
RETURN
END FUNCTION dos_ef
!a2F
subroutine lint ( nsym, s, minus_q, at, bg, npk, k1,k2,k3, &
nk1,nk2,nk3, nks, xk, kunit, nkBZ, eqBZ, sBZ)
!-----------------------------------------------------------------------
!
! Find which k-points of a uniform grid are in the IBZ
!
use kinds, only : DP
implicit none
integer, intent (IN) :: nks, nsym, s(3,3,48), npk, k1, k2, k3, &
nk1, nk2, nk3, kunit, nkBZ
logical, intent (IN) :: minus_q
real(kind=DP), intent(IN):: at(3,3), bg(3,3), xk(3,npk)
integer, INTENT(OUT) :: eqBZ(nkBZ), sBZ(nkBZ)
!
real(kind=DP) :: xkr(3), deltap(3), deltam(3)
real(kind=DP), parameter:: eps=1.0d-5
real(kind=DP), allocatable :: xkg(:,:), xp(:,:)
integer :: i,j,k, ns, n, nk
integer :: nkh
!
! Re-generate a uniform grid of k-points xkg
!
allocate (xkg( 3,nkBZ))
!
if(kunit < 1 .or. kunit > 2) call errore('lint','bad kunit value',kunit)
!
! kunit=2: get only "true" k points, not k+q points, from the list
!
nkh = nks/kunit
allocate (xp(3,nkh))
if (kunit == 1) then
xp(:,1:nkh) = xk(:,1:nkh)
else
do j=1,nkh
xp(:,j) = xk(:,2*j-1)
enddo
end if
do i=1,nk1
do j=1,nk2
do k=1,nk3
n = (k-1) + (j-1)*nk3 + (i-1)*nk2*nk3 + 1
xkg(1,n) = dble(i-1)/nk1 + dble(k1)/2/nk1
xkg(2,n) = dble(j-1)/nk2 + dble(k2)/2/nk2
xkg(3,n) = dble(k-1)/nk3 + dble(k3)/2/nk3
end do
end do
end do
call cryst_to_cart (nkh,xp,at,-1)
do nk=1,nkBZ
do n=1,nkh
do ns=1,nsym
do i=1,3
xkr(i) = s(i,1,ns) * xp(1,n) + &
s(i,2,ns) * xp(2,n) + &
s(i,3,ns) * xp(3,n)
end do
do i=1,3
deltap(i) = xkr(i)-xkg(i,nk) - nint (xkr(i)-xkg(i,nk) )
deltam(i) = xkr(i)+xkg(i,nk) - nint (xkr(i)+xkg(i,nk) )
end do
if ( sqrt ( deltap(1)**2 + &
deltap(2)**2 + &
deltap(3)**2 ) < eps .or. ( minus_q .and. &
sqrt ( deltam(1)**2 + &
deltam(2)**2 + &
deltam(3)**2 ) < eps ) ) then
eqBZ(nk) = n
sBZ(nk) = ns
go to 15
end if
end do
end do
call errore('lint','cannot locate k point xk',nk)
15 continue
end do
do n=1,nkh
do nk=1,nkBZ
if (eqBZ(nk) == n) go to 20
end do
! this failure of the algorithm may indicate that the displaced grid
! (with k1,k2,k3.ne.0) does not have the full symmetry of the lattice
call errore('lint','cannot remap grid on k-point list',n)
20 continue
end do
deallocate(xkg)
deallocate(xp)
return
end subroutine lint