9
1
mirror of https://github.com/QuantumPackage/qp2.git synced 2024-06-14 00:25:17 +02:00
qp2/src/scf_utils/rh_scf_mo.irp.f
2022-12-10 14:14:45 +01:00

309 lines
8.7 KiB
Fortran

! ---
subroutine Roothaan_Hall_SCF_MO()
BEGIN_DOC
!
! Roothaan-Hall algorithm for SCF Hartree-Fock calculation
!
END_DOC
implicit none
double precision :: energy_SCF, energy_SCF_previous, Delta_energy_SCF
double precision :: max_error_DIIS
double precision, allocatable :: Fock_matrix_DIIS(:,:,:), error_matrix_DIIS(:,:,:)
integer :: iteration_SCF, dim_DIIS, index_dim_DIIS
integer :: i, j
double precision :: level_shift_save
double precision, allocatable :: mo_coef_save(:,:)
logical, external :: qp_stop
PROVIDE ao_md5 mo_occ level_shift
allocate( mo_coef_save(ao_num,mo_num) &
, Fock_matrix_DIIS (mo_num,mo_num,max_dim_DIIS) &
, error_matrix_DIIS(mo_num,mo_num,max_dim_DIIS) )
Fock_matrix_DIIS = 0.d0
error_matrix_DIIS = 0.d0
mo_coef_save = 0.d0
call write_time(6)
print*,'energy of the guess = ',SCF_energy
write(6,'(A4, 1X, A16, 1X, A16, 1X, A16, 1X, A16)') &
'====','================','================','================','================'
write(6,'(A4, 1X, A16, 1X, A16, 1X, A16, 1X, A16)') &
' N ', 'energy ', 'energy diff ', 'DIIS error ', 'Level shift '
write(6,'(A4, 1X, A16, 1X, A16, 1X, A16, 1X, A16)') &
'====','================','================','================','================'
! Initialize energies and density matrices
energy_SCF_previous = SCF_energy
Delta_energy_SCF = 1.d0
iteration_SCF = 0
dim_DIIS = 0
max_error_DIIS = 1.d0
!
! Start of main SCF loop
!
PROVIDE Fock_matrix_mo error_diis_Fmo
do while ( &
( (max_error_DIIS > threshold_DIIS_nonzero) .or. &
(dabs(Delta_energy_SCF) > thresh_SCF) &
) .and. (iteration_SCF < n_it_SCF_max) )
iteration_SCF += 1
if(frozen_orb_scf) then
call initialize_mo_coef_begin_iteration
endif
dim_DIIS = min(dim_DIIS+1, max_dim_DIIS)
if( (scf_algorithm == 'DIIS_MO').and.(dabs(Delta_energy_SCF) > 1.d-6)) then
!if(scf_algorithm == 'DIIS_MO') then
index_dim_DIIS = mod(dim_DIIS-1, max_dim_DIIS) + 1
do j = 1, mo_num
do i = 1, mo_num
Fock_matrix_DIIS (i,j,index_dim_DIIS) = Fock_matrix_mo(i,j)
error_matrix_DIIS(i,j,index_dim_DIIS) = error_diis_Fmo(i,j)
enddo
enddo
call extrapolate_Fock_matrix_mo(error_matrix_DIIS, Fock_matrix_DIIS, Fock_matrix_mo, size(Fock_matrix_mo, 1), iteration_SCF, dim_DIIS)
do i = 1, mo_num
Fock_matrix_diag_mo(i) = Fock_matrix_mo(i,i)
enddo
TOUCH Fock_matrix_mo fock_matrix_diag_mo
endif
mo_coef = eigenvectors_Fock_matrix_mo
if(frozen_orb_scf) then
call reorder_core_orb
call initialize_mo_coef_begin_iteration
endif
TOUCH mo_coef
max_error_DIIS = maxval(Abs(error_diis_Fmo))
energy_SCF = SCF_energy
Delta_energy_SCF = energy_SCF - energy_SCF_previous
if( (SCF_algorithm == 'DIIS_MO') .and. (Delta_energy_SCF > 0.d0) ) then
Fock_matrix_MO(1:mo_num,1:mo_num) = Fock_matrix_DIIS(1:mo_num,1:mo_num,index_dim_DIIS)
do i = 1, mo_num
Fock_matrix_diag_mo(i) = Fock_matrix_mo(i,i)
enddo
TOUCH Fock_matrix_mo fock_matrix_diag_mo
mo_coef = eigenvectors_Fock_matrix_mo
max_error_DIIS = maxval(Abs(error_diis_Fmo))
energy_SCF = SCF_energy
Delta_energy_SCF = energy_SCF - energy_SCF_previous
endif
level_shift_save = level_shift
mo_coef_save(1:ao_num,1:mo_num) = mo_coef(1:ao_num,1:mo_num)
do while(Delta_energy_SCF > 0.d0)
mo_coef(1:ao_num,1:mo_num) = mo_coef_save(1:ao_num,1:mo_num)
if(level_shift <= .1d0) then
level_shift = 1.d0
else
level_shift = level_shift * 3.0d0
endif
TOUCH mo_coef level_shift
mo_coef(1:ao_num,1:mo_num) = eigenvectors_Fock_matrix_mo(1:ao_num,1:mo_num)
if(frozen_orb_scf) then
call reorder_core_orb
call initialize_mo_coef_begin_iteration
endif
TOUCH mo_coef
Delta_energy_SCF = SCF_energy - energy_SCF_previous
energy_SCF = SCF_energy
if(level_shift-level_shift_save > 40.d0) then
level_shift = level_shift_save * 4.d0
SOFT_TOUCH level_shift
exit
endif
dim_DIIS=0
enddo
level_shift = level_shift * 0.5d0
SOFT_TOUCH level_shift
energy_SCF_previous = energy_SCF
! Print results at the end of each iteration
write(6,'(I4, 1X, F16.10, 1X, F16.10, 1X, F16.10, 1X, F16.10, 1X, I3)') &
iteration_SCF, energy_SCF, Delta_energy_SCF, max_error_DIIS, level_shift, dim_DIIS
if(Delta_energy_SCF < 0.d0) then
call save_mos
endif
if(qp_stop()) exit
enddo
!
! End of Main SCF loop
!
if(iteration_SCF < n_it_SCF_max) then
mo_label = 'Canonical'
endif
write(6,'(A4, 1X, A16, 1X, A16, 1X, A16, 1X, A16)') &
'====','================','================','================','================'
write(6,*)
if(.not.frozen_orb_scf)then
call mo_as_eigvectors_of_mo_matrix(Fock_matrix_mo, size(Fock_matrix_mo, 1), size(Fock_matrix_mo, 2), mo_label, 1, .true.)
call restore_symmetry(ao_num, mo_num, mo_coef, size(mo_coef, 1), 1.d-10)
call orthonormalize_mos
call save_mos
endif
call write_double(6, energy_SCF, 'SCF energy')
call write_time(6)
end
! ---
subroutine extrapolate_Fock_matrix_mo(error_matrix_DIIS, Fock_matrix_DIIS, Fock_matrix_MO_, size_Fock_matrix_MO, iteration_SCF, dim_DIIS)
BEGIN_DOC
! Compute the extrapolated Fock matrix using the DIIS procedure
END_DOC
implicit none
integer,intent(inout) :: dim_DIIS
double precision,intent(in) :: Fock_matrix_DIIS(mo_num,mo_num,dim_DIIS), error_matrix_DIIS(mo_num,mo_num,dim_DIIS)
integer,intent(in) :: iteration_SCF, size_Fock_matrix_MO
double precision,intent(inout):: Fock_matrix_MO_(size_Fock_matrix_MO,mo_num)
double precision,allocatable :: B_matrix_DIIS(:,:),X_vector_DIIS(:)
double precision,allocatable :: C_vector_DIIS(:)
double precision,allocatable :: scratch(:,:)
integer :: i,j,k,l,i_DIIS,j_DIIS
double precision :: rcond, ferr, berr
integer, allocatable :: iwork(:)
integer :: lwork
if(dim_DIIS < 1) then
return
endif
allocate( &
B_matrix_DIIS(dim_DIIS+1,dim_DIIS+1), &
X_vector_DIIS(dim_DIIS+1), &
C_vector_DIIS(dim_DIIS+1), &
scratch(mo_num,mo_num) &
)
! Compute the matrices B and X
B_matrix_DIIS(:,:) = 0.d0
do j = 1, dim_DIIS
j_DIIS = min(dim_DIIS, mod(iteration_SCF-j, max_dim_DIIS) + 1)
do i = 1, dim_DIIS
i_DIIS = min(dim_DIIS, mod(iteration_SCF-i, max_dim_DIIS) + 1)
! Compute product of two errors vectors
do l = 1, mo_num
do k = 1, mo_num
B_matrix_DIIS(i,j) = B_matrix_DIIS(i,j) + error_matrix_DIIS(k,l,i_DIIS) * error_matrix_DIIS(k,l,j_DIIS)
enddo
enddo
enddo
enddo
! Pad B matrix and build the X matrix
C_vector_DIIS(:) = 0.d0
do i = 1, dim_DIIS
B_matrix_DIIS(i,dim_DIIS+1) = -1.d0
B_matrix_DIIS(dim_DIIS+1,i) = -1.d0
enddo
C_vector_DIIS(dim_DIIS+1) = -1.d0
deallocate(scratch)
! Estimate condition number of B
double precision :: anorm
integer :: info
integer,allocatable :: ipiv(:)
double precision, allocatable :: AF(:,:)
double precision, external :: dlange
lwork = max((dim_DIIS+1)**2, (dim_DIIS+1)*5)
allocate(AF(dim_DIIS+1,dim_DIIS+1))
allocate(ipiv(2*(dim_DIIS+1)), iwork(2*(dim_DIIS+1)) )
allocate(scratch(lwork,1))
scratch(:,1) = 0.d0
anorm = dlange('1', dim_DIIS+1, dim_DIIS+1, B_matrix_DIIS, size(B_matrix_DIIS, 1), scratch(1,1))
AF(:,:) = B_matrix_DIIS(:,:)
call dgetrf(dim_DIIS+1, dim_DIIS+1, AF, size(AF, 1), ipiv, info)
if(info /= 0) then
dim_DIIS = 0
return
endif
call dgecon( '1', dim_DIIS+1, AF, size(AF, 1), anorm, rcond, scratch, iwork, info)
if(info /= 0) then
dim_DIIS = 0
return
endif
if(rcond < 1.d-14) then
dim_DIIS = 0
return
endif
! solve the linear system C = B.X
X_vector_DIIS = C_vector_DIIS
call dgesv(dim_DIIS+1 , 1, B_matrix_DIIS, size(B_matrix_DIIS, 1), ipiv, X_vector_DIIS, size(X_vector_DIIS, 1), info)
deallocate(scratch, AF, iwork)
if(info < 0) then
stop 'bug in DIIS_MO'
endif
! Compute extrapolated Fock matrix
!$OMP PARALLEL DO PRIVATE(i,j,k) DEFAULT(SHARED) if (mo_num > 200)
do j = 1, mo_num
do i = 1, mo_num
Fock_matrix_MO_(i,j) = 0.d0
enddo
do k = 1, dim_DIIS
if(dabs(X_vector_DIIS(k)) < 1.d-10) cycle
do i = 1, mo_num
! FPE here
Fock_matrix_MO_(i,j) = Fock_matrix_MO_(i,j) + X_vector_DIIS(k) * Fock_matrix_DIIS(i,j,dim_DIIS-k+1)
enddo
enddo
enddo
!$OMP END PARALLEL DO
end