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https://github.com/LCPQ/quantum_package
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422 lines
12 KiB
FortranFixed
422 lines
12 KiB
FortranFixed
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subroutine CISD_SC2(dets_in,u_in,energies,dim_in,sze,N_st,Nint)
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use bitmasks
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implicit none
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BEGIN_DOC
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! CISD+SC2 method :: take off all the disconnected terms of a CISD (selected or not)
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!
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! dets_in : bitmasks corresponding to determinants
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!
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! u_in : guess coefficients on the various states. Overwritten
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! on exit
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!
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! dim_in : leftmost dimension of u_in
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!
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! sze : Number of determinants
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!
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! N_st : Number of eigenstates
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!
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! Initial guess vectors are not necessarily orthonormal
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END_DOC
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integer, intent(in) :: dim_in, sze, N_st, Nint
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integer(bit_kind), intent(in) :: dets_in(Nint,2,sze)
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double precision, intent(inout) :: u_in(dim_in,N_st)
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double precision, intent(out) :: energies(N_st)
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PROVIDE ref_bitmask_energy
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ASSERT (N_st > 0)
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ASSERT (sze > 0)
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ASSERT (Nint > 0)
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ASSERT (Nint == N_int)
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integer :: iter
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integer :: i,j,k,l,m
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logical :: converged
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double precision :: overlap(N_st,N_st)
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double precision :: u_dot_v, u_dot_u
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integer :: degree,N_double,index_hf,index_double(sze)
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double precision :: hij_elec, e_corr_double,e_corr,diag_h_mat_elem,inv_c0
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double precision :: e_corr_array(sze),H_jj_ref(sze),H_jj_dressed(sze),hij_double(sze)
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double precision :: e_corr_double_before,accu,cpu_2,cpu_1
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integer :: i_ok
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!$OMP PARALLEL DEFAULT(NONE) &
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!$OMP SHARED(sze,N_st, &
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!$OMP H_jj_ref,Nint,dets_in,u_in) &
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!$OMP PRIVATE(i)
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!$OMP DO
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do i=1,sze
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H_jj_ref(i) = diag_h_mat_elem(dets_in(1,1,i),Nint)
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enddo
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!$OMP END DO NOWAIT
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!$OMP END PARALLEL
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N_double = 0
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e_corr = 0.d0
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e_corr_double = 0.d0
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do i = 1, sze
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call get_excitation_degree(ref_bitmask,dets_in(1,1,i),degree,Nint)
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if(degree==0)then
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index_hf=i
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else if (degree == 2)then
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N_double += 1
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index_double(N_double) = i
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call i_H_j(ref_bitmask,dets_in(1,1,i),Nint,hij_elec)
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hij_double(N_double) = hij_elec
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e_corr_array(N_double) = u_in(i,1)* hij_elec
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e_corr_double += e_corr_array(N_double)
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e_corr += e_corr_array(N_double)
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index_double(N_double) = i
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else if (degree == 1)then
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call i_H_j(ref_bitmask,dets_in(1,1,i),Nint,hij_elec)
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print*,hij_elec
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e_corr += u_in(i,1)* hij_elec
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endif
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enddo
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inv_c0 = 1.d0/u_in(index_hf,1)
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do i = 1, N_double
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e_corr_array(i) = e_corr_array(i) * inv_c0
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enddo
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e_corr = e_corr * inv_c0
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e_corr_double = e_corr_double * inv_c0
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print*, 'E_corr = ',e_corr
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print*, 'E_corr_double = ', e_corr_double
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converged = .False.
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e_corr_double_before = e_corr_double
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iter = 0
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do while (.not.converged)
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iter +=1
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print*,'SC2 iteration : ',iter
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call cpu_time(cpu_1)
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do i=1,sze
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H_jj_dressed(i) = H_jj_ref(i)
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if (i==index_hf)cycle
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accu = 0.d0
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do j=1,N_double
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call repeat_excitation(dets_in(1,1,i),ref_bitmask,dets_in(1,1,index_double(j)),i_ok,Nint)
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if (i_ok==1)cycle! you check if the excitation is possible
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accu += e_corr_array(j)
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enddo
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H_jj_dressed(i) += accu
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enddo
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call cpu_time(cpu_2)
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print*,'time for the excitations = ',cpu_2 - cpu_1
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print*,H_jj_ref(1),H_jj_ref(2)
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print*,H_jj_dressed(1),H_jj_dressed(2)
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print*,u_in(index_hf,1),u_in(index_double(1),1)
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call davidson_diag_hjj(dets_in,u_in,H_jj_dressed,energies,dim_in,sze,N_st,Nint)
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print*,u_in(index_hf,1),u_in(index_double(1),1)
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e_corr_double = 0.d0
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inv_c0 = 1.d0/u_in(index_hf,1)
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do i = 1, N_double
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e_corr_array(i) = u_in(index_double(i),1)*inv_c0 * hij_double(i)
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e_corr_double += e_corr_array(i)
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enddo
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print*,'E_corr = ',e_corr_double
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print*,'delta E_corr =',e_corr_double - e_corr_double_before
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converged = dabs(e_corr_double - e_corr_double_before) < 1.d-10
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if (converged) then
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exit
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endif
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e_corr_double_before = e_corr_double
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enddo
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end
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subroutine davidson_diag_hjj(dets_in,u_in,H_jj,energies,dim_in,sze,N_st,Nint)
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use bitmasks
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implicit none
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BEGIN_DOC
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! Davidson diagonalization with specific diagonal elements of the H matrix
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!
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! H_jj : specific diagonal H matrix elements to diagonalize de Davidson
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!
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! dets_in : bitmasks corresponding to determinants
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!
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! u_in : guess coefficients on the various states. Overwritten
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! on exit
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!
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! dim_in : leftmost dimension of u_in
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!
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! sze : Number of determinants
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!
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! N_st : Number of eigenstates
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!
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! Initial guess vectors are not necessarily orthonormal
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END_DOC
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integer, intent(in) :: dim_in, sze, N_st, Nint
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integer(bit_kind), intent(in) :: dets_in(Nint,2,sze)
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double precision, intent(in) :: H_jj(dim_in)
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double precision, intent(inout) :: u_in(dim_in,N_st)
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double precision, intent(out) :: energies(N_st)
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integer :: iter
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integer :: i,j,k,l,m
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logical :: converged
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double precision :: overlap(N_st,N_st)
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double precision :: u_dot_v, u_dot_u
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integer, allocatable :: kl_pairs(:,:)
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integer :: k_pairs, kl
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integer :: iter2
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double precision, allocatable :: W(:,:,:), U(:,:,:), R(:,:)
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double precision, allocatable :: y(:,:,:,:), h(:,:,:,:), lambda(:)
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double precision :: diag_h_mat_elem
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double precision :: residual_norm(N_st)
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PROVIDE ref_bitmask_energy
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allocate( &
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kl_pairs(2,N_st*(N_st+1)/2), &
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W(sze,N_st,davidson_sze_max), &
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U(sze,N_st,davidson_sze_max), &
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R(sze,N_st), &
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h(N_st,davidson_sze_max,N_st,davidson_sze_max), &
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y(N_st,davidson_sze_max,N_st,davidson_sze_max), &
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lambda(N_st*davidson_sze_max))
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ASSERT (N_st > 0)
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ASSERT (sze > 0)
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ASSERT (Nint > 0)
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ASSERT (Nint == N_int)
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! Initialization
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! ==============
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k_pairs=0
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do l=1,N_st
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do k=1,l
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k_pairs+=1
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kl_pairs(1,k_pairs) = k
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kl_pairs(2,k_pairs) = l
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enddo
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enddo
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!$OMP PARALLEL DEFAULT(NONE) &
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!$OMP SHARED(U,sze,N_st,overlap,kl_pairs,k_pairs, &
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!$OMP Nint,dets_in,u_in) &
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!$OMP PRIVATE(k,l,kl,i)
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! Orthonormalize initial guess
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! ============================
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!$OMP DO
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do kl=1,k_pairs
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k = kl_pairs(1,kl)
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l = kl_pairs(2,kl)
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if (k/=l) then
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overlap(k,l) = u_dot_v(U_in(1,k),U_in(1,l),sze)
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overlap(l,k) = overlap(k,l)
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else
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overlap(k,k) = u_dot_u(U_in(1,k),sze)
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endif
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enddo
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!$OMP END DO
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!$OMP END PARALLEL
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call ortho_lowdin(overlap,size(overlap,1),N_st,U_in,size(U_in,1),sze)
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! Davidson iterations
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! ===================
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converged = .False.
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do while (.not.converged)
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!$OMP PARALLEL DEFAULT(NONE) &
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!$OMP PRIVATE(k,i) SHARED(U,u_in,sze,N_st)
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do k=1,N_st
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!$OMP DO
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do i=1,sze
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U(i,k,1) = u_in(i,k)
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enddo
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!$OMP END DO
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enddo
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!$OMP END PARALLEL
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do iter=1,davidson_sze_max-1
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! Compute W_k = H |u_k>
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! ----------------------
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do k=1,N_st
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call H_u_0(W(1,k,iter),U(1,k,iter),H_jj,sze,dets_in,Nint)
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enddo
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! Compute h_kl = <u_k | W_l> = <u_k| H |u_l>
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! -------------------------------------------
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do l=1,N_st
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do k=1,N_st
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do iter2=1,iter-1
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h(k,iter2,l,iter) = u_dot_v(U(1,k,iter2),W(1,l,iter),sze)
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h(k,iter,l,iter2) = h(k,iter2,l,iter)
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enddo
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enddo
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do k=1,l
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h(k,iter,l,iter) = u_dot_v(U(1,k,iter),W(1,l,iter),sze)
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h(l,iter,k,iter) = h(k,iter,l,iter)
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enddo
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enddo
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! Diagonalize h
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! -------------
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call lapack_diag(lambda,y,h,N_st*davidson_sze_max,N_st*iter)
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! Express eigenvectors of h in the determinant basis
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! --------------------------------------------------
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! call dgemm ( 'N','N', sze, N_st*iter, N_st, &
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! 1.d0, U(1,1,1), size(U,1), y(1,1,1,1), size(y,1)*size(y,2), &
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! 0.d0, U(1,1,iter+1), size(U,1) )
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do k=1,N_st
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do i=1,sze
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U(i,k,iter+1) = 0.d0
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W(i,k,iter+1) = 0.d0
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do l=1,N_st
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do iter2=1,iter
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U(i,k,iter+1) = U(i,k,iter+1) + U(i,l,iter2)*y(l,iter2,k,1)
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W(i,k,iter+1) = W(i,k,iter+1) + W(i,l,iter2)*y(l,iter2,k,1)
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enddo
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enddo
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enddo
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enddo
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! Compute residual vector
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! -----------------------
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do k=1,N_st
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do i=1,sze
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R(i,k) = lambda(k) * U(i,k,iter+1) - W(i,k,iter+1)
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enddo
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residual_norm(k) = u_dot_u(R(1,k),sze)
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enddo
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print '(I3,15(F16.8,x))', iter, lambda(1:N_st) + nuclear_repulsion
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print '(3x,15(E16.5,x))', residual_norm(1:N_st)
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converged = maxval(residual_norm) < 1.d-10
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if (converged) then
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exit
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endif
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! Davidson step
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! -------------
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do k=1,N_st
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do i=1,sze
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U(i,k,iter+1) = 1.d0/(lambda(k) - H_jj(i)) * R(i,k)
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enddo
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enddo
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! Gram-Schmidt
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! ------------
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double precision :: c
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do k=1,N_st
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do iter2=1,iter
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do l=1,N_st
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c = u_dot_v(U(1,k,iter+1),U(1,l,iter2),sze)
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do i=1,sze
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U(i,k,iter+1) -= c * U(i,l,iter2)
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enddo
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enddo
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enddo
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do l=1,k-1
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c = u_dot_v(U(1,k,iter+1),U(1,l,iter+1),sze)
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do i=1,sze
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U(i,k,iter+1) -= c * U(i,l,iter+1)
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enddo
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enddo
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call normalize( U(1,k,iter+1), sze )
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enddo
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enddo
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|
|
if (.not.converged) then
|
||
|
|
iter = davidson_sze_max-1
|
||
|
|
endif
|
||
|
|
|
||
|
|
! Re-contract to u_in
|
||
|
|
! -----------
|
||
|
|
|
||
|
|
do k=1,N_st
|
||
|
|
energies(k) = lambda(k)
|
||
|
|
do i=1,sze
|
||
|
|
u_in(i,k) = 0.d0
|
||
|
|
do iter2=1,iter
|
||
|
|
do l=1,N_st
|
||
|
|
u_in(i,k) += U(i,l,iter2)*y(l,iter2,k,1)
|
||
|
|
enddo
|
||
|
|
enddo
|
||
|
|
enddo
|
||
|
|
enddo
|
||
|
|
|
||
|
|
enddo
|
||
|
|
|
||
|
|
deallocate ( &
|
||
|
|
kl_pairs, &
|
||
|
|
W, &
|
||
|
|
U, &
|
||
|
|
R, &
|
||
|
|
h, &
|
||
|
|
y, &
|
||
|
|
lambda &
|
||
|
|
)
|
||
|
|
end
|
||
|
|
|
||
|
|
subroutine repeat_excitation(key_in,key_1,key_2,i_ok,Nint)
|
||
|
|
use bitmasks
|
||
|
|
implicit none
|
||
|
|
integer(bit_kind), intent(in) :: key_in(Nint,2),key_1(Nint,2),key_2(Nint,2),Nint
|
||
|
|
integer,intent(out):: i_ok
|
||
|
|
integer :: ispin,i_hole,k_hole,j_hole,i_particl,k_particl,j_particl,i_trou,degree,exc(0:2,2,2)
|
||
|
|
double precision :: phase
|
||
|
|
i_ok = 1
|
||
|
|
call get_excitation(key_1,key_2,exc,degree,phase,Nint)
|
||
|
|
integer :: h1,p1,h2,p2,s1,s2
|
||
|
|
if(degree==2)then
|
||
|
|
call decode_exc(exc,degree,h1,p1,h2,p2,s1,s2)
|
||
|
|
! first hole
|
||
|
|
k_hole = ishft(h1-1,-5)+1
|
||
|
|
j_hole = h1-ishft(k_hole-1,5)-1
|
||
|
|
if(iand(key_in(k_hole,s1),ibset(0,j_hole)).eq.0)then
|
||
|
|
i_ok = 0
|
||
|
|
return
|
||
|
|
endif
|
||
|
|
|
||
|
|
! second hole
|
||
|
|
k_hole = ishft(h2-1,-5)+1
|
||
|
|
j_hole = h2-ishft(k_hole-1,5)-1
|
||
|
|
if(iand(key_in(k_hole,s2),ibset(0,j_hole)).eq.0)then
|
||
|
|
i_ok = 0
|
||
|
|
return
|
||
|
|
endif
|
||
|
|
|
||
|
|
! first particle
|
||
|
|
k_particl = ishft(p1-1,-5)+1
|
||
|
|
j_particl = p1-ishft(k_particl-1,5)-1
|
||
|
|
if(iand(key_in(k_particl,s1),ibset(0,j_particl)).ne.0)then
|
||
|
|
i_ok = 0
|
||
|
|
return
|
||
|
|
endif
|
||
|
|
|
||
|
|
! second particle
|
||
|
|
k_particl = ishft(p2-1,-5)+1
|
||
|
|
j_particl = p2-ishft(k_particl-1,5)-1
|
||
|
|
if(iand(key_in(k_particl,s2),ibset(0,j_particl)).ne.0)then
|
||
|
|
i_ok = 0
|
||
|
|
return
|
||
|
|
endif
|
||
|
|
return
|
||
|
|
endif
|
||
|
|
end
|
||
|
|
|