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mirror of https://github.com/QuantumPackage/qp2.git synced 2024-11-14 01:13:38 +01:00
qp2/src/scf_utils/roothaan_hall_scf.irp.f
2020-05-25 23:27:38 +02:00

329 lines
9.5 KiB
Fortran

subroutine Roothaan_Hall_SCF
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,max_error_DIIS_alpha,max_error_DIIS_beta
double precision, allocatable :: Fock_matrix_DIIS(:,:,:),error_matrix_DIIS(:,:,:)
integer :: iteration_SCF,dim_DIIS,index_dim_DIIS
integer :: i,j
logical, external :: qp_stop
double precision, allocatable :: mo_coef_save(:,:)
PROVIDE ao_md5 mo_occ level_shift
allocate(mo_coef_save(ao_num,mo_num), &
Fock_matrix_DIIS (ao_num,ao_num,max_dim_DIIS), &
error_matrix_DIIS(ao_num,ao_num,max_dim_DIIS) &
)
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 FPS_SPF_matrix_AO Fock_matrix_AO
do while ( &
( (max_error_DIIS > threshold_DIIS_nonzero) .or. &
(dabs(Delta_energy_SCF) > thresh_SCF) &
) .and. (iteration_SCF < n_it_SCF_max) )
! Increment cycle number
iteration_SCF += 1
if(frozen_orb_scf)then
call initialize_mo_coef_begin_iteration
endif
! Current size of the DIIS space
dim_DIIS = min(dim_DIIS+1,max_dim_DIIS)
if (scf_algorithm == 'DIIS') then
! Store Fock and error matrices at each iteration
do j=1,ao_num
do i=1,ao_num
index_dim_DIIS = mod(dim_DIIS-1,max_dim_DIIS)+1
Fock_matrix_DIIS (i,j,index_dim_DIIS) = Fock_matrix_AO(i,j)
error_matrix_DIIS(i,j,index_dim_DIIS) = FPS_SPF_matrix_AO(i,j)
enddo
enddo
! Compute the extrapolated Fock matrix
call extrapolate_Fock_matrix( &
error_matrix_DIIS,Fock_matrix_DIIS, &
Fock_matrix_AO,size(Fock_matrix_AO,1), &
iteration_SCF,dim_DIIS &
)
Fock_matrix_AO_alpha = Fock_matrix_AO*0.5d0
Fock_matrix_AO_beta = Fock_matrix_AO*0.5d0
TOUCH Fock_matrix_AO_alpha Fock_matrix_AO_beta
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
! Calculate error vectors
max_error_DIIS = maxval(Abs(FPS_SPF_Matrix_MO))
! SCF energy
energy_SCF = SCF_energy
Delta_Energy_SCF = energy_SCF - energy_SCF_previous
if ( (SCF_algorithm == 'DIIS').and.(Delta_Energy_SCF > 0.d0) ) then
Fock_matrix_AO(1:ao_num,1:ao_num) = Fock_matrix_DIIS (1:ao_num,1:ao_num,index_dim_DIIS)
Fock_matrix_AO_alpha = Fock_matrix_AO*0.5d0
Fock_matrix_AO_beta = Fock_matrix_AO*0.5d0
TOUCH Fock_matrix_AO_alpha Fock_matrix_AO_beta
endif
double precision :: level_shift_save
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
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
if (iteration_SCF < n_it_SCF_max) then
mo_label = "Canonical"
endif
!
! End of Main SCF loop
!
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 save_mos
endif
call write_double(6, Energy_SCF, 'SCF energy')
call write_time(6)
end
subroutine extrapolate_Fock_matrix( &
error_matrix_DIIS,Fock_matrix_DIIS, &
Fock_matrix_AO_,size_Fock_matrix_AO, &
iteration_SCF,dim_DIIS &
)
BEGIN_DOC
! Compute the extrapolated Fock matrix using the DIIS procedure
END_DOC
implicit none
double precision,intent(in) :: Fock_matrix_DIIS(ao_num,ao_num,*),error_matrix_DIIS(ao_num,ao_num,*)
integer,intent(in) :: iteration_SCF, size_Fock_matrix_AO
double precision,intent(inout):: Fock_matrix_AO_(size_Fock_matrix_AO,ao_num)
integer,intent(inout) :: dim_DIIS
double precision,allocatable :: B_matrix_DIIS(:,:),X_vector_DIIS(:)
double precision,allocatable :: C_vector_DIIS(:)
double precision,allocatable :: scratch(:,:)
integer :: i,j,k,i_DIIS,j_DIIS
double precision :: rcond, ferr, berr
integer, allocatable :: iwork(:)
integer :: lwork
if (dim_DIIS < 4) 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(ao_num,ao_num) &
)
! Compute the matrices B and X
do j=1,dim_DIIS
do i=1,dim_DIIS
j_DIIS = mod(iteration_SCF-j,max_dim_DIIS)+1
i_DIIS = mod(iteration_SCF-i,max_dim_DIIS)+1
! Compute product of two errors vectors
call dgemm('N','N',ao_num,ao_num,ao_num, &
1.d0, &
error_matrix_DIIS(1,1,i_DIIS),size(error_matrix_DIIS,1), &
error_matrix_DIIS(1,1,j_DIIS),size(error_matrix_DIIS,1), &
0.d0, &
scratch,size(scratch,1))
! Compute Trace
B_matrix_DIIS(i,j) = 0.d0
do k=1,ao_num
B_matrix_DIIS(i,j) = B_matrix_DIIS(i,j) + scratch(k,k)
enddo
enddo
enddo
! Pad B matrix and build the X matrix
do i=1,dim_DIIS
B_matrix_DIIS(i,dim_DIIS+1) = -1.d0
B_matrix_DIIS(dim_DIIS+1,i) = -1.d0
C_vector_DIIS(i) = 0.d0
enddo
B_matrix_DIIS(dim_DIIS+1,dim_DIIS+1) = 0.d0
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))
anorm = dlange('1', dim_DIIS+1, dim_DIIS+1, B_matrix_DIIS, &
size(B_matrix_DIIS,1), scratch)
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-10) 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)
! call dsysvx('N','U',dim_DIIS+1,1, &
! B_matrix_DIIS,size(B_matrix_DIIS,1), &
! AF, size(AF,1), &
! ipiv, &
! C_vector_DIIS,size(C_vector_DIIS,1), &
! X_vector_DIIS,size(X_vector_DIIS,1), &
! rcond, &
! ferr, &
! berr, &
! scratch,size(scratch), &
! iwork, &
! info &
! )
deallocate(scratch,AF,iwork)
if(info < 0) then
stop 'bug in DIIS'
endif
! Compute extrapolated Fock matrix
!$OMP PARALLEL DO PRIVATE(i,j,k) DEFAULT(SHARED) if (ao_num > 200)
do j=1,ao_num
do i=1,ao_num
Fock_matrix_AO_(i,j) = 0.d0
enddo
do k=1,dim_DIIS
if (dabs(X_vector_DIIS(k)) < 1.d-10) cycle
do i=1,ao_num
Fock_matrix_AO_(i,j) = Fock_matrix_AO_(i,j) + &
X_vector_DIIS(k)*Fock_matrix_DIIS(i,j,dim_DIIS-k+1)
enddo
enddo
enddo
!$OMP END PARALLEL DO
end