quantum-espresso/PW/compute_scf.f90

416 lines
12 KiB
Fortran

!
! Copyright (C) 2002-2008 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 .
!
#include "f_defs.h"
!
!----------------------------------------------------------------------------
SUBROUTINE compute_scf( fii, lii, stat )
!----------------------------------------------------------------------------
!
! ... this subroutine is the main scf-driver for all "path" calculations
! ... ( called by Modules/path_base.f90/born_oppenheimer() subroutine )
!
! ... for each image in the path, it performs the self-consistent loop
! ... computing the energy and the forces
!
! ... Written by Carlo Sbraccia (2003-2006)
!
USE input_parameters, ONLY : startingwfc, startingpot
USE basis, ONLY : starting_wfc, starting_pot
USE kinds, ONLY : DP
USE constants, ONLY : e2
USE control_flags, ONLY : conv_elec, istep, history, pot_order
USE check_stop, ONLY : check_stop_now
USE vlocal, ONLY : strf
USE cell_base, ONLY : bg, alat
USE gvect, ONLY : ngm, g, nr1, nr2, nr3, eigts1, eigts2, eigts3
USE ions_base, ONLY : tau, nat, nsp, ityp
USE ener, ONLY : etot
USE force_mod, ONLY : force
USE io_files, ONLY : prefix, tmp_dir, iunpath, iunupdate, &
exit_file, iunexit, delete_if_present
USE path_formats, ONLY : scf_fmt, scf_fmt_para
USE path_variables, ONLY : pos, pes, grad_pes, dim1, pending_image, &
istep_path, frozen, num_of_images, &
first_last_opt
USE io_global, ONLY : stdout, ionode, ionode_id, meta_ionode
USE mp_global, ONLY : inter_image_comm, intra_image_comm, &
my_image_id, nimage, root_image
USE mp, ONLY : mp_bcast, mp_barrier, mp_sum, mp_min
USE path_io_routines, ONLY : new_image_init, get_new_image, &
stop_other_images
!
IMPLICIT NONE
!
INTEGER, INTENT(IN) :: fii, lii ! indexes to first and last images
LOGICAL, INTENT(OUT) :: stat
!
INTEGER :: fii_, lii_ ! local copies of fii and lii
INTEGER :: image, istat
REAL(DP) :: tcpu
CHARACTER (LEN=256) :: tmp_dir_saved
LOGICAL :: file_exists, opnd
REAL(DP), ALLOCATABLE :: tauold(:,:,:)
! previous positions of atoms (needed by extrapolation)
!
CHARACTER(LEN=6), EXTERNAL :: int_to_char
!
!
fii_ = fii
lii_ = lii
!
istep = istep_path
istat = 0
!
CALL flush_unit( iunpath )
!
ALLOCATE( tauold( 3, nat, 3 ) )
!
tmp_dir_saved = tmp_dir
!
IF ( nimage > 1 ) THEN
!
! ... vectors pes and grad_pes are initalized to zero for all images on
! ... all nodes: this is needed for the final mp_sum()
!
IF ( my_image_id == root_image ) THEN
!
FORALL( image = fii:lii, .NOT.frozen(image) )
!
pes(image) = 0.D0
grad_pes(:,image) = 0.D0
!
END FORALL
!
ELSE
!
pes(fii:lii) = 0.D0
grad_pes(:,fii:lii) = 0.D0
!
END IF
!
END IF
!
! ... all processes are syncronized (needed to have a readable output)
!
CALL mp_barrier()
!
IF ( nimage > 1 .AND. .NOT.first_last_opt ) THEN
!
! ... self-consistency on the first and last images is done separately
!
IF ( fii == 1 ) THEN
!
IF ( my_image_id == root_image ) THEN
!
CALL do_scf( 1, istat )
!
IF ( istat /= 0 ) GOTO 1
!
END IF
!
fii_ = 2
!
END IF
IF ( lii == num_of_images ) THEN
!
IF ( my_image_id == root_image + 1 ) THEN
!
CALL do_scf( num_of_images, istat )
!
IF ( istat /= 0 ) GOTO 1
!
END IF
!
lii_ = lii - 1
!
END IF
!
END IF
!
! ... only the first cpu initializes the file needed by parallelization
! ... among images
!
IF ( meta_ionode ) CALL new_image_init( fii_, tmp_dir_saved )
!
image = fii_ + my_image_id
!
scf_loop: DO
!
! ... exit if available images are finished
!
IF ( image > lii_ ) EXIT scf_loop
!
pending_image = image
!
CALL do_scf( image, istat )
!
IF ( istat /= 0 ) GOTO 1
!
! ... the new image is obtained (by ionode only)
!
CALL get_new_image( image, tmp_dir_saved )
!
CALL mp_bcast( image, ionode_id, intra_image_comm )
!
END DO scf_loop
!
! ... after the first call to compute_scf the input values of startingpot
! ... and startingwfc are both set to 'file'
!
startingpot = 'file'
startingwfc = 'file'
starting_pot = startingpot
starting_wfc = startingwfc
!
! ... finalization of the job (this point is also reached in case of error
! ... condition)
!
1 CALL mp_barrier()
!
DEALLOCATE( tauold )
!
IF ( nimage > 1 ) THEN
!
! ... pes and grad_pes are communicated among "image" pools
!
CALL mp_sum( pes(fii:lii), inter_image_comm )
CALL mp_sum( grad_pes(:,fii:lii), inter_image_comm )
CALL mp_sum( istat, inter_image_comm )
!
END IF
!
! ... global status is computed here
!
IF ( istat == 0 ) THEN
!
stat = .TRUE.
!
pending_image = 0
!
ELSE
!
stat = .FALSE.
!
IF ( nimage > 1 ) THEN
!
CALL mp_min( pending_image, inter_image_comm )
!
IF ( meta_ionode ) CALL delete_if_present( exit_file )
!
END IF
!
IF ( meta_ionode ) THEN
!
! ... some image didn't converge: extrapolation is no longer
! ... possible, files are removed
!
WRITE( UNIT = iunpath, &
FMT = '(/,5X,"cleaning-up extrapolation files"/)' )
!
DO image = pending_image, lii
!
tmp_dir = TRIM( tmp_dir_saved ) // TRIM( prefix ) // "_" // &
TRIM( int_to_char( image ) ) // "/"
!
CALL delete_if_present( TRIM( tmp_dir ) // &
TRIM( prefix ) // '.update' )
!
END DO
!
END IF
!
END IF
!
tmp_dir = tmp_dir_saved
!
RETURN
!
CONTAINS
!
!-----------------------------------------------------------------------
SUBROUTINE do_scf( image, istat )
!-----------------------------------------------------------------------
!
USE input_parameters, ONLY : diago_thr_init
USE control_flags, ONLY : ethr
!
IMPLICIT NONE
!
INTEGER, INTENT(IN) :: image
INTEGER, INTENT(INOUT) :: istat
!
REAL(DP), EXTERNAL :: get_clock
!
! ... self-consistency ( for non-frozen images only )
!
IF ( frozen(image) ) RETURN
!
CALL clean_pw( .FALSE. )
!
tcpu = get_clock( 'PWSCF' )
!
IF ( nimage > 1 ) THEN
!
WRITE( UNIT = iunpath, FMT = scf_fmt_para ) my_image_id, tcpu, image
!
ELSE
!
WRITE( UNIT = iunpath, FMT = scf_fmt ) tcpu, image
!
END IF
!
tmp_dir = TRIM( tmp_dir_saved ) // TRIM( prefix ) // "_" // &
TRIM( int_to_char( image ) ) // "/"
!
! ... unit stdout is connected to the appropriate file
!
IF ( ionode ) THEN
!
INQUIRE( UNIT = stdout, OPENED = opnd )
IF ( opnd ) CLOSE( UNIT = stdout )
OPEN( UNIT = stdout, FILE = TRIM( tmp_dir ) // 'PW.out', &
STATUS = 'UNKNOWN', POSITION = 'APPEND' )
!
END IF
!
! ... tau is in alat units ( pos is in bohr )
!
tau = RESHAPE( pos(:,image), SHAPE( tau ) ) / alat
!
WRITE( stdout, '(/,5X,"coordinates at iteration ",I3,/)' ) istep
!
CALL output_tau( .FALSE. )
!
! ... initialization of the scf calculation
!
CALL setup ()
CALL init_run()
!
IF ( ionode ) THEN
!
! ... the file containing old positions is opened
! ... ( needed for extrapolation )
!
CALL seqopn( iunupdate, 'update', 'FORMATTED', file_exists )
!
IF ( file_exists ) THEN
!
READ( UNIT = iunupdate, FMT = * ) history
READ( UNIT = iunupdate, FMT = * ) tauold
!
ELSE
!
history = 0
tauold = 0.D0
!
WRITE( UNIT = iunupdate, FMT = * ) history
WRITE( UNIT = iunupdate, FMT = * ) tauold
!
END IF
!
CLOSE( UNIT = iunupdate, STATUS = 'KEEP' )
!
END IF
!
CALL mp_bcast( history, ionode_id, intra_image_comm )
CALL mp_bcast( tauold, ionode_id, intra_image_comm )
!
IF ( history > 0 ) THEN
!
! ... potential and wavefunctions are extrapolated only if
! ... we are starting a new self-consistency ( scf on the
! ... previous image was achieved )
!
IF ( pot_order > 0 ) THEN
!
! ... structure factors of the old positions are computed
! ... (needed for the old atomic charge)
!
CALL struc_fact( nat, tauold(:,:,1), nsp, ityp, ngm, g, bg, &
nr1, nr2, nr3, strf, eigts1, eigts2, eigts3 )
!
END IF
!
CALL update_pot()
!
END IF
!
! ... self-consistency loop
!
CALL electrons()
!
CALL punch( 'all' )
!
! ... scf convergence is checked here
!
IF ( .NOT.conv_elec ) THEN
!
istat = 1
!
WRITE( UNIT = iunpath, &
FMT = '(/,5X,"WARNING : scf convergence ", &
& "NOT achieved on image ",I3)' ) image
!
! ... in case of parallelization on images a stop signal
! ... is sent via the "EXIT" file
!
IF ( nimage > 1 ) CALL stop_other_images()
!
RETURN
!
END IF
!
! ... self-consistent forces
!
CALL forces()
!
! ... energy is converted from rydberg to hartree
!
pes(image) = etot / e2
!
! ... gradients are converted from rydberg/bohr to hartree/bohr
!
grad_pes(:,image) = - RESHAPE( force, (/ dim1 /) ) / e2
!
IF ( ionode ) THEN
!
! ... save the previous two steps
! ... ( a total of three ionic steps is saved )
!
tauold(:,:,3) = tauold(:,:,2)
tauold(:,:,2) = tauold(:,:,1)
tauold(:,:,1) = tau(:,:)
!
history = MIN( 3, ( history + 1 ) )
!
CALL seqopn( iunupdate, 'update', 'FORMATTED', file_exists )
!
WRITE( UNIT = iunupdate, FMT = * ) history
WRITE( UNIT = iunupdate, FMT = * ) tauold
!
CLOSE( UNIT = iunupdate, STATUS = 'KEEP' )
!
END IF
!
! ... input values are restored at the end of each iteration ( they are
! ... modified by init_run )
!
starting_pot = startingpot
starting_wfc = startingwfc
!
ethr = diago_thr_init
!
CALL close_files()
CALL reset_k_points ( )
!
RETURN
!
END SUBROUTINE do_scf
!
END SUBROUTINE compute_scf