quantum-espresso/PHonon/PH/dynmatrix.f90

240 lines
8.0 KiB
Fortran

!
! Copyright (C) 2001-2008 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 dynmatrix_new(iq_)
!-----------------------------------------------------------------------
!
! This routine is a driver which computes the symmetrized dynamical
! matrix at q (and in the star of q) and diagonalizes it.
! It writes the result on a iudyn file and writes the eigenvalues on
! output.
!
!
USE kinds, ONLY : DP
USE constants, ONLY : FPI, BOHR_RADIUS_ANGS
USE ions_base, ONLY : nat, ntyp => nsp, ityp, tau, atm, amass, zv
USE io_global, ONLY : stdout
USE control_flags, ONLY : modenum
USE cell_base, ONLY : at, bg, celldm, ibrav, omega
USE symm_base, ONLY : s, sr, irt, nsym, invs, t_rev
USE dynmat, ONLY : dyn, w2
USE noncollin_module, ONLY : nspin_mag
USE modes, ONLY : u, nmodes, npert, nirr, num_rap_mode
USE gamma_gamma, ONLY : nasr, asr, equiv_atoms, has_equivalent, &
n_diff_sites
USE efield_mod, ONLY : epsilon, zstareu, zstarue0, zstarue
USE disp, ONLY : omega_disp
USE control_ph, ONLY : always_run
USE control_ph, ONLY : epsil, zue, lgamma_gamma, search_sym, ldisp, &
done_zue, where_rec, &
rec_code, ldiag, done_epsil, done_zeu, xmldyn, &
current_iq, qplot
USE ph_restart, ONLY : ph_writefile
USE partial, ONLY : all_comp, comp_irr, done_irr, nat_todo_input
USE units_ph, ONLY : iudyn
USE noncollin_module, ONLY : m_loc, nspin_mag
USE output, ONLY : fildyn
USE io_dyn_mat, ONLY : write_dyn_mat_header
USE ramanm, ONLY : lraman, ramtns
USE lr_symm_base, ONLY : minus_q, irotmq, nsymq, rtau
USE qpoint, ONLY : xq
USE control_lr, ONLY : lgamma
implicit none
INTEGER, INTENT(IN) :: iq_
! local variables
!
integer :: nq, isq (48), imq, na, nt, imode0, jmode0, irr, jrr, &
ipert, jpert, mu, nu, i, j, nqq
! 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), work(3)
! list of vectors in the star of q
real(DP), allocatable :: zstar(:,:,:)
integer :: icart, jcart, ierr
logical :: ldiag_loc
!
call start_clock('dynmatrix')
ldiag_loc=ldiag.OR.(nat_todo_input > 0).OR.all_comp
!
! set all noncomputed elements to zero
!
if (.not.lgamma_gamma) then
imode0 = 0
do irr = 1, nirr
jmode0 = 0
do jrr = 1, nirr
if (.NOT.done_irr (irr).and..NOT.done_irr (jrr)) then
do ipert = 1, npert (irr)
mu = imode0 + ipert
do jpert = 1, npert (jrr)
nu = jmode0 + jpert
dyn (mu, nu) = CMPLX(0.d0, 0.d0,kind=DP)
enddo
enddo
elseif (.NOT.done_irr (irr) .AND. done_irr (jrr) ) then
do ipert = 1, npert (irr)
mu = imode0 + ipert
do jpert = 1, npert (jrr)
nu = jmode0 + jpert
dyn (mu, nu) = CONJG(dyn (nu, mu) )
enddo
enddo
endif
jmode0 = jmode0 + npert (jrr)
enddo
imode0 = imode0 + npert (irr)
enddo
else
do irr = 1, nirr
if (.NOT.comp_irr(irr)) then
do nu=1,3*nat
dyn(irr,nu)=(0.d0,0.d0)
enddo
endif
enddo
endif
!
! Symmetrizes the dynamical matrix w.r.t. the small group of q
!
IF (lgamma_gamma) THEN
CALL generate_dynamical_matrix (nat, nsym, s, invs, irt, at, bg, &
n_diff_sites, equiv_atoms, has_equivalent, dyn)
IF (asr) CALL set_asr_c(nat,nasr,dyn)
ELSE
CALL symdyn_munu_new (dyn, u, xq, s, invs, rtau, irt, at, bg, &
nsymq, nat, irotmq, minus_q)
ENDIF
!
! if only one mode is computed write the dynamical matrix and stop
!
if (modenum .ne. 0) then
WRITE( stdout, '(/,5x,"Dynamical matrix:")')
do nu = 1, 3 * nat
WRITE( stdout, '(5x,2i5,2f10.6)') modenum, nu, dyn (modenum, nu)
enddo
call stop_ph (.true.)
endif
IF ( .NOT. ldiag_loc ) THEN
DO irr=0,nirr
IF (.NOT.done_irr(irr)) THEN
IF (.not.ldisp.AND..NOT.always_run) THEN
WRITE(stdout, '(/,5x,"Stopping because representation", &
& i5, " is not done")') irr
CALL close_phq(.TRUE.)
CALL stop_smoothly_ph(.TRUE.)
ELSE
WRITE(stdout, '(/5x,"Not diagonalizing because representation", &
& i5, " is not done")') irr
END IF
RETURN
ENDIF
ENDDO
ldiag_loc=.TRUE.
ENDIF
!
! Generates the star of q
!
call star_q1(xq, at, bg, nsym, s, invs, nq, sxq, isq, imq, .TRUE., t_rev )
!
! write on file information on the system
!
IF (xmldyn) THEN
nqq=nq
IF (imq==0) nqq=2*nq
IF (lgamma.AND.done_epsil.AND.done_zeu) THEN
CALL write_dyn_mat_header( fildyn, ntyp, nat, ibrav, nspin_mag, &
celldm, at, bg, omega, atm, amass, tau, ityp, m_loc, &
nqq, epsilon, zstareu, lraman, ramtns)
ELSE
CALL write_dyn_mat_header( fildyn, ntyp, nat, ibrav, nspin_mag, &
celldm, at, bg, omega, atm, amass, tau,ityp,m_loc,nqq)
ENDIF
ELSE
CALL write_old_dyn_mat_head(iudyn)
ENDIF
!
! Rotates and writes on iudyn the dynamical matrices of the star of q
!
call q2qstar_ph (dyn, at, bg, nat, nsym, s, invs, irt, rtau, &
nq, sxq, isq, imq, iudyn)
!
! Writes (if the case) results for quantities involving electric field
!
if (epsil) call write_epsilon_and_zeu (zstareu, epsilon, nat, iudyn)
IF (zue.AND..NOT.done_zue) THEN
IF (lgamma_gamma) THEN
ALLOCATE(zstar(3,3,nat))
zstar(:,:,:) = 0.d0
DO jcart = 1, 3
DO mu = 1, 3 * nat
na = (mu - 1) / 3 + 1
icart = mu - 3 * (na - 1)
zstar(jcart, icart, na) = zstarue0 (mu, jcart)
ENDDO
DO na=1,nat
work(:)=0.0_DP
DO icart=1,3
work(icart)=zstar(jcart,1,na)*at(1,icart)+ &
zstar(jcart,2,na)*at(2,icart)+ &
zstar(jcart,3,na)*at(3,icart)
ENDDO
zstar(jcart,:,na)=work(:)
ENDDO
ENDDO
CALL generate_effective_charges_c ( nat, nsym, s, invs, irt, at, bg, &
n_diff_sites, equiv_atoms, has_equivalent, asr, nasr, zv, ityp, &
ntyp, atm, zstar )
DO na=1,nat
do icart=1,3
zstarue(:,na,icart)=zstar(:,icart,na)
ENDDO
ENDDO
done_zue=.TRUE.
CALL summarize_zue()
DEALLOCATE(zstar)
ELSE
CALL sym_and_write_zue
ENDIF
ELSEIF (lgamma) THEN
IF (done_zue) CALL summarize_zue()
ENDIF
if (lraman) call write_ramtns (iudyn, ramtns)
!
! Diagonalizes the dynamical matrix at q
!
IF (ldiag_loc) THEN
call dyndia (xq, nmodes, nat, ntyp, ityp, amass, iudyn, dyn, w2)
IF (search_sym) THEN
CALL find_mode_sym_new (dyn, w2, tau, nat, nsymq, s, sr, irt, xq, &
rtau, amass, ntyp, ityp, 1, lgamma_gamma, .FALSE., &
num_rap_mode, ierr)
CALL print_mode_sym(w2, num_rap_mode, lgamma)
ENDIF
IF (qplot) omega_disp(:,current_iq)=w2(:)
END IF
!
! Here we save the dynamical matrix and the effective charges dP/du on
! the recover file. If a recover file with this very high recover code
! is found only the final result is rewritten on output.
!
rec_code=30
where_rec='dynmatrix.'
CALL ph_writefile('status_ph',current_iq,0,ierr)
call stop_clock('dynmatrix')
return
end subroutine dynmatrix_new