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QuantumPackage/plugins/local/non_hermit_dav/biorthog.irp.f
2024-05-01 23:10:18 +02:00

179 lines
4.6 KiB
Fortran

! ---
subroutine non_hrmt_bieig(n, A, thr_d, thr_nd, leigvec, reigvec, n_real_eigv, eigval)
BEGIN_DOC
!
! routine which returns the sorted REAL EIGENVALUES ONLY and corresponding LEFT/RIGHT eigenvetors
! of a non hermitian matrix A(n,n)
!
! n_real_eigv is the number of real eigenvalues, which might be smaller than the dimension "n"
!
END_DOC
implicit none
integer, intent(in) :: n
double precision, intent(in) :: A(n,n)
double precision, intent(in) :: thr_d, thr_nd
integer, intent(out) :: n_real_eigv
double precision, intent(out) :: reigvec(n,n), leigvec(n,n), eigval(n)
integer :: i, j,k
integer :: n_good
double precision :: thr, thr_cut, thr_diag, thr_norm
double precision :: accu_d, accu_nd
integer, allocatable :: list_good(:), iorder(:), deg_num(:)
double precision, allocatable :: WR(:), WI(:), VL(:,:), VR(:,:)
double precision, allocatable :: S(:,:)
double precision, allocatable :: phi_1_tilde(:),phi_2_tilde(:),chi_1_tilde(:),chi_2_tilde(:)
allocate(phi_1_tilde(n),phi_2_tilde(n),chi_1_tilde(n),chi_2_tilde(n))
allocate(WR(n), WI(n), VL(n,n), VR(n,n))
call lapack_diag_non_sym(n, A, WR, WI, VL, VR)
thr_diag = 1d-06
thr_norm = 1d+10
! ---
! track & sort the real eigenvalues
n_good = 0
thr = Im_thresh_tc
do i = 1, n
if(dabs(WI(i)) .lt. thr) then
n_good += 1
else
print*, 'Found an imaginary component to eigenvalue on i = ', i
print*, 'Re(i) + Im(i)', WR(i), WI(i)
endif
enddo
if(n_good.ne.n) then
print*,'there are some imaginary eigenvalues '
thr_diag = 1d-03
n_good = n
endif
allocate(list_good(n_good), iorder(n_good))
n_good = 0
do i = 1, n
n_good += 1
list_good(n_good) = i
eigval(n_good) = WR(i)
enddo
deallocate( WR, WI )
n_real_eigv = n_good
do i = 1, n_good
iorder(i) = i
enddo
call dsort(eigval, iorder, n_good)
reigvec(:,:) = 0.d0
leigvec(:,:) = 0.d0
do i = 1, n_real_eigv
do j = 1, n
reigvec(j,i) = VR(j,list_good(iorder(i)))
leigvec(j,i) = VL(j,list_good(iorder(i)))
enddo
enddo
deallocate( list_good, iorder )
deallocate( VL, VR )
ASSERT(n==n_real_eigv)
! ---
! check bi-orthogonality
thr_diag = 10.d0
thr_norm = 1d+10
allocate( S(n_real_eigv,n_real_eigv) )
call check_biorthog(n, n_real_eigv, leigvec, reigvec, accu_d, accu_nd, S, thr_d, thr_nd, .false.)
if( (accu_nd .lt. thr_nd) .and. (dabs(accu_d-dble(n_real_eigv))/dble(n_real_eigv) .lt. thr_d) ) then
print *, ' lapack vectors are normalized and bi-orthogonalized'
deallocate(S)
return
! accu_nd is modified after adding the normalization
elseif( (accu_nd .lt. thr_nd) .and. (dabs(accu_d-dble(n_real_eigv))/dble(n_real_eigv) .gt. thr_d) ) then
print *, ' lapack vectors are not normalized but bi-orthogonalized'
call check_biorthog_binormalize(n, n_real_eigv, leigvec, reigvec, thr_d, thr_nd, .true.)
call check_biorthog(n, n_real_eigv, leigvec, reigvec, accu_d, accu_nd, S, thr_d, thr_nd, .true.)
call check_EIGVEC(n, n, A, eigval, leigvec, reigvec, thr_diag, thr_norm, .true.)
deallocate(S)
return
else
print *, ' lapack vectors are not normalized neither bi-orthogonalized'
allocate(deg_num(n))
call reorder_degen_eigvec(n, deg_num, eigval, leigvec, reigvec)
call impose_biorthog_degen_eigvec(n, deg_num, eigval, leigvec, reigvec)
deallocate(deg_num)
call check_biorthog(n, n_real_eigv, leigvec, reigvec, accu_d, accu_nd, S, thr_d, thr_nd, .false.)
if( (accu_nd .lt. thr_nd) .and. (dabs(accu_d-dble(n_real_eigv)) .gt. thr_d) ) then
call check_biorthog_binormalize(n, n_real_eigv, leigvec, reigvec, thr_d, thr_nd, .true.)
endif
call check_biorthog(n, n_real_eigv, leigvec, reigvec, accu_d, accu_nd, S, thr_d, thr_nd, .true.)
deallocate(S)
endif
return
end
! ---
subroutine check_bi_ortho(reigvec, leigvec, n, S, accu_nd)
BEGIN_DOC
! retunrs the overlap matrix S = Leigvec^T Reigvec
!
! and the square root of the sum of the squared off-diagonal elements of S
END_DOC
implicit none
integer, intent(in) :: n
double precision, intent(in) :: reigvec(n,n), leigvec(n,n)
double precision, intent(out) :: S(n,n), accu_nd
integer :: i,j
! S = VL x VR
call dgemm( 'T', 'N', n, n, n, 1.d0 &
, leigvec, size(leigvec, 1), reigvec, size(reigvec, 1) &
, 0.d0, S, size(S, 1) )
accu_nd = 0.d0
do i = 1, n
do j = 1, n
if(i.ne.j) then
accu_nd = accu_nd + S(j,i) * S(j,i)
endif
enddo
enddo
accu_nd = dsqrt(accu_nd)
end