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qp_plugins_scemama/devel/svdwf/RSVD_ijHkl_det.irp.f
2021-11-02 16:18:07 +01:00

312 lines
8.3 KiB
Fortran

program RSVD_ijHkl_det
BEGIN_DOC
!
! decompose < di dj | H | dk dl > by a RSVD:
!
! H_{ik jl} = < di dj | H | dk dl >
! = \sum_{s=1}^{n_svd} U_{ik s} V_{jl s}
! = \sum_{s=1}^{n_svd} U_{ik s} U_{jl s}
!
! where n_svd << min( NaxNa , NbxNb )
!
END_DOC
read_wf = .true.
TOUCH read_wf
call run()
end
subroutine run()
implicit none
integer(bit_kind) :: det1(N_int,2), det2(N_int,2)
integer :: degree, i_state
double precision :: h12
integer*8 :: dim_Hdet
integer*8, allocatable :: Hdet_ik(:), Hdet_jl(:)
double precision, allocatable :: Hdet_v(:)
integer :: dim_U , dim_V, dim_RSVD
double precision :: t_beg, t_end
call wall_time(t_beg)
i_state = 1
det1(:,1) = psi_det_alpha_unique(:,1)
det2(:,1) = psi_det_alpha_unique(:,1)
det1(:,2) = psi_det_beta_unique(:,1)
det2(:,2) = psi_det_beta_unique(:,1)
call get_excitation_degree_spin(det1(1,1),det2(1,1),degree,N_int)
call get_excitation_degree(det1,det2,degree,N_int)
call i_H_j(det1, det2, N_int, h12)
! sparse representation of < di dj | H | dk dl >
!dim_Hdet = 7486379362
dim_Hdet = 1000000
allocate( Hdet_ik(dim_Hdet), Hdet_jl(dim_Hdet), Hdet_v(dim_Hdet) )
call const_ij_hdet_kl_sparse(dim_hdet, hdet_ik, hdet_jl, hdet_v)
! decompose Hdet by a Randomized SVD
dim_U = n_det_alpha_unique * n_det_alpha_unique
dim_V = n_det_beta_unique * n_det_beta_unique
dim_RSVD = min(dim_U, dim_V)
dim_RSVD = min(5000, dim_RSVD)
call perform_RSVD(dim_U, dim_V, dim_RSVD, dim_Hdet, Hdet_ik, Hdet_jl, Hdet_v)
deallocate( Hdet_ik, Hdet_jl, Hdet_v )
call wall_time(t_end)
print *, ' end after (min)', (t_end-t_beg)/60.d0
end
! _________________________________________________________________________________________________
! _________________________________________________________________________________________________
! _________________________________________________________________________________________________
! _________________________________________________________________________________________________
!
subroutine const_ij_Hdet_kl_sparse(dim_Hdet, Hdet_ik, Hdet_jl, Hdet_v)
implicit none
integer*8, intent(in) :: dim_Hdet
integer*8, intent(out) :: Hdet_ik(dim_Hdet), Hdet_jl(dim_Hdet)
double precision, intent(out) :: Hdet_v(dim_Hdet)
integer(bit_kind) :: det1(N_int,2), det2(N_int,2)
integer :: degree
integer :: na, nb, i, j, k, l, ii
double precision :: h12
double precision :: t1, t2
print *, ""
print *, " start const_ij_Hdet_kl_sparse"
call wall_time(t1)
na = n_det_alpha_unique
nb = n_det_beta_unique
ii = 0
!$OMP PARALLEL DEFAULT(NONE) &
!$OMP PRIVATE(i,j,k,l,ii,h12,det1,det2,degree) &
!$OMP SHARED(na,nb,psi_det_alpha_unique,psi_det_beta_unique, &
!$OMP N_int,Hdet_ik,Hdet_jl,Hdet_v)
!$OMP DO
do l = 1, nb
det2(:,2) = psi_det_beta_unique(:,l)
do j = 1, nb
det1(:,2) = psi_det_beta_unique(:,j)
call get_excitation_degree_spin(det1(1,2),det2(1,2),degree,N_int)
if(degree .gt. 2) cycle
do k = 1, na
det2(:,1) = psi_det_alpha_unique(:,k)
do i = 1, na
det1(:,1) = psi_det_alpha_unique(:,i)
call get_excitation_degree(det1,det2,degree,N_int)
if(degree .gt. 2) cycle
call i_H_j(det1, det2, N_int, h12)
if(dabs(h12) .le. (1d-15)) cycle
ii = ii + 1
Hdet_ik(ii) = (i-1)*na + k
Hdet_jl(ii) = (j-1)*na + l
Hdet_v (ii) = h12
enddo
enddo
enddo
enddo
!$OMP END DO
!$OMP END PARALLEL
call wall_time(t2)
print *, " end const_ij_Hdet_kl_sparse after (min) ", (t2-t1)/60.
print *, ""
if( ii .ne. dim_Hdet) then
print*, ' error in const_ij_Hdet_kl_sparse'
print*, ' dim supposed = ', dim_Hdet
print*, ' dim foundedi = ', ii
stop
end if
return
end subroutine const_ij_Hdet_kl_sparse
! _________________________________________________________________________________________________
! _________________________________________________________________________________________________
! _________________________________________________________________________________________________
!
subroutine perform_RSVD(dim_U, dim_V, dim_RSVD, dim_Hdet, Hdet_ik, Hdet_jl, Hdet_v)
include 'constants.include.F'
implicit none
integer, intent(in) :: dim_U, dim_V, dim_RSVD
integer*8, intent(in) :: dim_Hdet
integer*8, intent(in) :: Hdet_ik(dim_Hdet), Hdet_jl(dim_Hdet)
double precision, intent(in) :: Hdet_v(dim_Hdet)
integer :: na, nb
integer :: iter, iter_max
integer :: ii, rr, ik, jl
double precision, allocatable :: GR(:,:)
double precision, allocatable :: Z(:,:), P(:,:), Yt(:,:), UYt(:,:)
double precision, allocatable :: U(:,:), V(:,:), D(:)
na = n_det_alpha_unique
nb = n_det_beta_unique
! Z = Hdet x G
! G: random gauss dist
allocate( Z(dim_U,dim_RSVD) )
Z(:,:) = 0
!$OMP PARALLEL DEFAULT(NONE) PRIVATE(ii, rr, ik, GR) &
!$OMP SHARED(dim_Hdet, dim_RSVD, Z, Hdet_ik, Hdet_v)
allocate( GR(dim_Hdet,2) )
!$OMP DO
do rr = 1, dim_RSVD
call random_number(GR)
GR(:,1) = dsqrt(-2.d0*dlog(GR(:,1)))
GR(:,1) = GR(:,1) * dcos(dtwo_pi*GR(:,2))
do ii = 1, dim_Hdet
ik = Hdet_ik(ii)
!jl = Hdet_jl(ii)
Z(ik,rr) = Z(ik,rr) + Hdet_v(ii) * GR(ii,1)
enddo
enddo
!$OMP END DO
deallocate(GR)
!$OMP END PARALLEL
! parameter
iter_max = 10
allocate( P(dim_V,dim_RSVD) )
! ------------------------------------------------------------------------------------------
! Power iterations
!
do iter = 1, iter_max
print *, ' power iteration ', iter, '/', iter_max
!$OMP PARALLEL DEFAULT(NONE) PRIVATE(ii, rr, ik, jl) &
!$OMP SHARED(dim_Hdet, dim_RSVD, Z, P, Hdet_ik, Hdet_jl, Hdet_v)
!$OMP DO
! P = Hdet.T x Z
do rr = 1, dim_RSVD
P(:,rr) = 0.d0
do ii = 1, dim_Hdet
ik = Hdet_ik(ii)
jl = Hdet_jl(ii)
P(jl,rr) = P(jl,rr) + Hdet_v(ii) * Z(ik,rr)
enddo
enddo
!$OMP END DO
!$OMP BARRIER
!$OMP DO
do rr = 1, dim_RSVD
Z(:,rr) = 0.d0
do ii = 1, dim_Hdet
ik = Hdet_ik(ii)
jl = Hdet_jl(ii)
Z(ik,rr) = Z(ik,rr) + Hdet_v(ii) * P(jl,rr)
enddo
enddo
!$OMP END DO
!$OMP END PARALLEL
call ortho_qr(Z, size(Z,1), dim_U, dim_RSVD)
enddo
!
! ------------------------------------------------------------------------------------------
! Y = Z.T x Hdet
! Yt = Hdet.T x Z
allocate( Yt(dim_V,dim_RSVD) )
!$OMP PARALLEL DEFAULT(NONE) PRIVATE(ii, rr, ik, jl) &
!$OMP SHARED(dim_Hdet, dim_RSVD, Z, Yt, Hdet_ik, Hdet_jl, Hdet_v)
!$OMP DO
do rr = 1, dim_RSVD
Yt(:,rr) = 0.d0
do ii = 1, dim_Hdet
ik = Hdet_ik(ii)
jl = Hdet_jl(ii)
Yt(jl,rr) = Yt(jl,rr) + Z(ik,rr) * Hdet_v(ii)
enddo
enddo
!$OMP END DO
!$OMP END PARALLEL
! Y = U x D x Vt
! Yt = V x D x Ut
allocate( D(dim_RSVD), V(dim_V,dim_RSVD), UYt(dim_RSVD,dim_RSVD) )
call svd(Yt, size(Yt,1), V, size(V,1), D, UYt, size(UYt,1), dim_V, dim_RSVD)
deallocate( Yt )
! U = Z x UY
allocate( U(dim_U,dim_RSVD) )
call dgemm('N', 'T', dim_U, dim_RSVD, dim_RSVD, 1.d0, Z, size(Z,1), UYt, size(UYt,1), 0.d0, U, size(U,1))
deallocate( UYt, Z )
open(unit=41, file='u_det.txt', action='write')
do rr = 1, dim_RSVD
do ii = 1, dim_U
write(41,*) U(ii,rr)
enddo
enddo
close(41)
! v = u because H is symmetric
!open(unit=41, file='v_det.txt', action='write')
! do rr = 1, dim_RSVD
! do ii = 1, dim_V
! write(41,*) V(ii,rr)
! enddo
! enddo
!close(41)
open(unit=41, file='d_det.txt', action='write')
do rr = 1, dim_RSVD
write(41,*) D(rr), sum( D(1:rr)**2 )
enddo
close(41)
deallocate( U, D, V )
end subroutine perform_RSVD
! _________________________________________________________________________________________________
! _________________________________________________________________________________________________