SUBROUTINE green_linsys_shift (ik0) USE kinds, ONLY : DP USE ions_base, ONLY : nat, ntyp => nsp, ityp USE io_global, ONLY : stdout, ionode USE io_files, ONLY : prefix, iunigk USE check_stop, ONLY : check_stop_now USE wavefunctions_module, ONLY : evc USE constants, ONLY : degspin, pi, tpi, RYTOEV, eps8 USE cell_base, ONLY : tpiba2 USE ener, ONLY : ef USE klist, ONLY : xk, wk, nkstot USE gvect, ONLY : nrxx, g, nl, ngm, ecutwfc USE gsmooth, ONLY : doublegrid, nrxxs, nr1s, nr2s, nr3s, nrx1s, nrx2s, nrx3s, ngms USE lsda_mod, ONLY : lsda, nspin, current_spin, isk USE wvfct, ONLY : nbnd, npw, npwx, igk, g2kin, et USE uspp, ONLY : okvan, vkb USE uspp_param, ONLY : upf, nhm, nh USE noncollin_module, ONLY : noncolin, npol, nspin_mag USE paw_variables, ONLY : okpaw USE paw_onecenter, ONLY : paw_dpotential, paw_dusymmetrize, & paw_dumqsymmetrize USE control_gw, ONLY : rec_code, niter_gw, nmix_gw, tr2_gw, & alpha_pv, lgamma, lgamma_gamma, convt, & nbnd_occ, alpha_mix, ldisp, rec_code_read, & where_rec, flmixdpot, current_iq, & ext_recover, eta, tr2_green USE nlcc_gw, ONLY : nlcc_any USE units_gw, ONLY : iuwfc, lrwfc, iuwfcna, iungreen, lrgrn USE eqv, ONLY : evq, eprec USE qpoint, ONLY : xq, npwq, igkq, nksq, ikks, ikqs USE recover_mod, ONLY : read_rec, write_rec USE mp, ONLY : mp_sum USE disp, ONLY : nqs USE freq_gw, ONLY : fpol, fiu, nfs, nfsmax, nwgreen, wgreen, deltaw USE gwsigma, ONLY : ngmgrn, ecutsco USE mp_global, ONLY : inter_pool_comm, intra_pool_comm, mp_global_end, mpime, & nproc_pool, nproc, me_pool, my_pool_id, npool USE mp, ONLY: mp_barrier, mp_bcast, mp_sum IMPLICIT NONE real(DP) :: thresh, anorm, averlt, dr2, sqrtpi logical :: conv_root !should be freq blocks... COMPLEX(DP) :: gr_A_shift(npwx, nwgreen) COMPLEX(DP) :: gr_A(npwx, 1), rhs(npwx , 1) COMPLEX(DP) :: gr(npwx, 1), ci, cw, green(ngmgrn, ngmgrn, nwgreen) COMPLEX(DP), ALLOCATABLE :: etc(:,:) INTEGER :: iw, igp, iwi INTEGER :: iq, ik0 INTEGER :: rec0, n1, gveccount REAL(DP) :: dirac, x, delta, support real(DP) :: k0mq(3) real(DP) :: w_ryd(nwgreen) external cg_psi, cch_psi_all_fix, cch_psi_all_green INTEGER, ALLOCATABLE :: niters(:) REAL(DP) , allocatable :: h_diag (:,:) REAL(DP) :: eprec_gamma integer :: kter, & ! counter on iterations iter0, & ! starting iteration ipert, & ! counter on perturbations ibnd, & ! counter on bands iter, & ! counter on iterations lter, & ! counter on iterations of linear system ltaver, & ! average counter lintercall, & ! average number of calls to cgsolve_all ik, ikk, & ! counter on k points ikq, & ! counter on k+q points ig, & ! counter on G vectors ndim, & ! integer actual row dimension of dpsi is, & ! counter on spin polarizations nt, & ! counter on types na, & ! counter on atoms nrec, nrec1,& ! the record number for dvpsi and dpsi ios, & ! integer variable for I/O control mode ! mode index !HL need a threshold here for the linear system solver. This could also go in the punch card !with some default at a later date. REAL(DP) :: tr_cgsolve = 1.0d-8 !Arrays to handle case where nlsco does not contain all G vectors required for |k+G| < ecut INTEGER :: igkq_ig(npwx) INTEGER :: igkq_tmp(npwx) INTEGER :: counter !PARALLEL INTEGER :: igstart, igstop, ngpool, ngr, igs, ngvecs !tmp number of blocks INTEGER :: nblocks, block allocate (h_diag (npwx, 1)) allocate (etc(nbnd, nkstot)) ci = (0.0d0, 1.0d0) nblocks = 1 !We support the numerical delta fxn in a x eV window... support = 2.0d0/RYTOEV !Convert freq array generated in freqbins into rydbergs. w_ryd(:) = wgreen(:)/RYTOEV CALL start_clock('greenlinsys') where_rec='no_recover' if (nksq.gt.1) rewind (unit = iunigk) !Loop over q in the IBZ_{k} do iq = 1, nksq if (lgamma) then ikq = iq else ikq = 2*iq endif if (nksq.gt.1) then read (iunigk, err = 100, iostat = ios) npw, igk 100 call errore ('green_linsys', 'reading igk', abs (ios) ) endif if(lgamma) npwq=npw if (.not.lgamma.and.nksq.gt.1) then read (iunigk, err = 200, iostat = ios) npwq, igkq 200 call errore ('green_linsys', 'reading igkq', abs (ios) ) endif !write(1000+mpime,*) igkq !Need a loop to find all plane waves below ecutsco when igkq takes us outside of this sphere. !igkq_tmp is gamma centered index up to ngmsco, !igkq_ig is the linear index for looping up to npwq. !need to loop over... counter = 0 igkq_tmp(:) = 0 igkq_ig(:) = 0 do ig = 1, npwx if((igkq(ig).le.ngmgrn).and.((igkq(ig)).gt.0)) then counter = counter + 1 !index in total G grid. igkq_tmp (counter) = igkq(ig) !index for loops igkq_ig (counter) = ig endif enddo !Difference in parallelization routine. Instead of parallelizing over the usual list of G-vectors as in the straight !forward pilot implementation I need to first generate the list of igkq's within my correlation cutoff !this gives the number of vectors that requires parallelizing over. Then I split the work (up to counter) between the !nodes as with the coulomb i.e. igstart and igstop. #ifdef __PARA npool = nproc / nproc_pool write(stdout,'("npool", i4, i5)') npool, counter if (npool.gt.1) then ! number of g-vec per pool and reminder ngpool = counter / npool ngr = counter - ngpool * npool ! the remainder goes to the first ngr pools if ( my_pool_id < ngr ) ngpool = ngpool + 1 igs = ngpool * my_pool_id + 1 if ( my_pool_id >= ngr ) igs = igs + ngr ! the index of the first and the last g vec in this pool igstart = igs igstop = igs - 1 + ngpool write (stdout,'(/4x,"Max n. of G vecs in Green_linsys per pool = ",i5)') igstop-igstart+1 else #endif igstart = 1 igstop = counter #ifdef __PARA endif #endif !allocate list to keep track of the number of residuals for each G-vector: ngvecs = igstop-igstart + 1 if(.not.allocated(niters)) ALLOCATE(niters(ngvecs)) niters = 0 ! Now the G-vecs up to the correlation cutoff have been divided between pools. ! Calculates beta functions (Kleinman-Bylander projectors), with ! structure factor, for all atoms, in reciprocal space call init_us_2 (npwq, igkq, xk (1, ikq), vkb) call davcio (evq, lrwfc, iuwfc, ikq, - 1) do ig = 1, npwq g2kin (ig) = ((xk (1,ikq) + g (1, igkq(ig) ) ) **2 + & (xk (2,ikq) + g (2, igkq(ig) ) ) **2 + & (xk (3,ikq) + g (3, igkq(ig) ) ) **2 ) * tpiba2 enddo WRITE(6, '(4x,"k0+q = (",3f12.7," )",10(3x,f7.3))') xk(:,ikq), et(:,ikq)*RYTOEV WRITE(6, '(4x,"tr_green for green_linsys",e10.3)') tr2_green green = (0.0d0, 0.0d0) h_diag = 0.d0 !No preconditioning with multishift do ig = 1, npwx h_diag(ig,1) = 1.0d0 enddo !Due to memory constraints we might break up the green's fxn into frequency blocks: !On first frequency block we do the seed system with BiCG: gveccount = 1 do ig = igstart, igstop do block = 1, nblocks rhs(:,:) = (0.0d0, 0.0d0) rhs(igkq_ig(ig), 1) = -(1.0d0, 0.0d0) gr_A(:,:) = (0.0d0, 0.0d0) lter = 0 etc(:, :) = CMPLX( 0.0d0, 0.0d0, kind=DP) cw = CMPLX( 0, 0, kind=DP) !Doing Linear System with Wavefunction cutoff (full density) for each perturbation. WRITE(6,'("Starting BiCG")') if (block.eq.1) then call cbcg_solve_green(cch_psi_all_green, cg_psi, etc(1,ikq), rhs, gr_A, h_diag, & npwx, npwq, tr_cgsolve, ikq, lter, conv_root, anorm, 1, npol, & cw, niters(gveccount)) if(.not.conv_root) write(600+mpime, '("root not converged.")') if(.not.conv_root) write(600+mpime, *) anorm endif call green_multishift(npwx, npwq, nwgreen, niters(gveccount), 1, gr_A_shift) do iw = 1, nwgreen do igp = 1, counter green (igkq_tmp(ig), igkq_tmp(igp),iw) = green (igkq_tmp(ig), igkq_tmp(igp),iw) + & gr_A_shift(igkq_ig(igp),iw) !green (igkq_tmp(ig), igkq_tmp(igp),iw) = green (igkq_tmp(ig), igkq_tmp(igp),iw) + & ! conjg(gr_A_shift(igkq_ig(igp),iw)) enddo enddo gveccount = gveccount + 1 !Green's Fxn Non-analytic Component: !HLGREEN TEST do iw = 1, nwgreen do igp = 1, counter !should be nbnd_occ: do ibnd = 1, nbnd x = et(ibnd, ikq) - w_ryd(iw) dirac = eta / pi / (x**2.d0 + eta**2.d0) green(igkq_tmp(ig), igkq_tmp(igp), iw) = green(igkq_tmp(ig), igkq_tmp(igp), iw) + & tpi*ci*conjg(evq(igkq_ig(ig), ibnd)) * & (evq(igkq_ig(igp), ibnd)) * dirac enddo enddo!igp enddo!iw enddo !blocks enddo !ig #ifdef __PARA !upper limit on mp_barrier communicate? CALL mp_barrier(inter_pool_comm) !Collect all elements of green's matrix from different processors. CALL mp_sum (green, inter_pool_comm ) CALL mp_barrier(inter_pool_comm) if(ionode) then #endif do iw = 1, nwgreen rec0 = (iw-1) * 1 * nksq + (iq-1) + 1 CALL davcio(green(:,:,iw), lrgrn, iungreen, rec0, +1, ios) enddo #ifdef __PARA endif CALL mp_barrier(inter_pool_comm) #endif ENDDO !iq if(allocated(niters)) DEALLOCATE(niters) if(allocated(h_diag)) DEALLOCATE(h_diag) if(allocated(etc)) DEALLOCATE(etc) CALL stop_clock('greenlinsys') RETURN END SUBROUTINE green_linsys_shift