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mirror of https://github.com/QuantumPackage/qp2.git synced 2024-12-22 19:43:32 +01:00
qp2/src/scf_utils/diagonalize_fock.irp.f

93 lines
2.2 KiB
Fortran

BEGIN_PROVIDER [ double precision, eigenvectors_Fock_matrix_mo, (ao_num,mo_num) ]
implicit none
BEGIN_DOC
! Eigenvectors of the Fock matrix in the |MO| basis obtained with level shift.
END_DOC
integer :: i,j
integer :: liwork, lwork, n, info
integer, allocatable :: iwork(:)
double precision, allocatable :: work(:), F(:,:), F_save(:,:)
double precision, allocatable :: diag(:)
allocate( F(mo_num,mo_num), F_save(mo_num,mo_num) )
allocate (diag(mo_num) )
do j=1,mo_num
do i=1,mo_num
F(i,j) = Fock_matrix_mo(i,j)
enddo
enddo
if(frozen_orb_scf)then
integer :: iorb,jorb
do i = 1, n_core_orb
iorb = list_core(i)
do j = 1, n_act_orb
jorb = list_act(j)
F(iorb,jorb) = 0.d0
F(jorb,iorb) = 0.d0
enddo
enddo
endif
! Insert level shift here
do i = elec_beta_num+1, elec_alpha_num
F(i,i) += 0.5d0*level_shift
enddo
do i = elec_alpha_num+1, mo_num
F(i,i) += level_shift
enddo
n = mo_num
lwork = 1+6*n + 2*n*n
liwork = 3 + 5*n
allocate(work(lwork))
allocate(iwork(liwork) )
lwork = -1
liwork = -1
F_save = F
call dsyevd( 'V', 'U', mo_num, F, &
size(F,1), diag, work, lwork, iwork, liwork, info)
if (info /= 0) then
print *, irp_here//' DSYEVD failed : ', info
stop 1
endif
lwork = int(work(1))
liwork = iwork(1)
deallocate(iwork)
deallocate(work)
allocate(work(lwork))
allocate(iwork(liwork) )
call dsyevd( 'V', 'U', mo_num, F, &
size(F,1), diag, work, lwork, iwork, liwork, info)
deallocate(iwork)
if (info /= 0) then
F = F_save
call dsyev( 'V', 'L', mo_num, F, &
size(F,1), diag, work, lwork, info)
if (info /= 0) then
print *, irp_here//' DSYEV failed : ', info
stop 1
endif
endif
call dgemm('N','N',ao_num,mo_num,mo_num, 1.d0, &
mo_coef, size(mo_coef,1), F, size(F,1), &
0.d0, eigenvectors_Fock_matrix_mo, size(eigenvectors_Fock_matrix_mo,1))
deallocate(work, F, F_save, diag)
END_PROVIDER