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quantum_package/plugins/eginer/CISD_SC2/SC2.irp.f

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7.6 KiB
Fortran
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2018-10-19 11:32:58 +02:00
subroutine CISD_SC2(dets_in,u_in,energies,diag_H_elements,dim_in,sze,N_st,Nint,convergence)
use bitmasks
implicit none
BEGIN_DOC
! CISD+SC2 method :: take off all the disconnected terms of a CISD (selected or not)
!
! dets_in : bitmasks corresponding to determinants
!
! u_in : guess coefficients on the various states. Overwritten
! on exit
!
! dim_in : leftmost dimension of u_in
!
! sze : Number of determinants
!
! N_st : Number of eigenstates
!
! Initial guess vectors are not necessarily orthonormal
END_DOC
integer, intent(in) :: dim_in, sze, N_st, Nint
integer(bit_kind), intent(in) :: dets_in(Nint,2,sze)
double precision, intent(inout) :: u_in(dim_in,N_st)
double precision, intent(out) :: energies(N_st)
double precision, intent(out) :: diag_H_elements(dim_in)
double precision, intent(in) :: convergence
ASSERT (N_st > 0)
ASSERT (sze > 0)
ASSERT (Nint > 0)
ASSERT (Nint == N_int)
integer :: iter
integer :: i,j,k,l,m
logical :: converged
double precision :: overlap(N_st,N_st)
double precision :: u_dot_v, u_dot_u
integer :: degree,N_double,index_hf
double precision :: hij_elec, e_corr_double,e_corr,diag_h_mat_elem,inv_c0
double precision :: e_corr_double_before,accu,cpu_2,cpu_1
integer,allocatable :: degree_exc(:), index_double(:)
integer :: i_ok
double precision,allocatable :: e_corr_array(:),H_jj_ref(:),H_jj_dressed(:),hij_double(:)
integer(bit_kind), allocatable :: doubles(:,:,:)
allocate (doubles(Nint,2,sze),e_corr_array(sze),H_jj_ref(sze),H_jj_dressed(sze),&
index_double(sze), degree_exc(sze), hij_double(sze))
call write_time(6)
write(6,'(A)') ''
write(6,'(A)') 'CISD SC2'
write(6,'(A)') '========'
!$OMP PARALLEL DEFAULT(NONE) &
!$OMP SHARED(sze,N_st, &
!$OMP H_jj_ref,Nint,dets_in,u_in) &
!$OMP PRIVATE(i)
!$OMP DO SCHEDULE(guided)
do i=1,sze
H_jj_ref(i) = diag_h_mat_elem(dets_in(1,1,i),Nint)
enddo
!$OMP END DO NOWAIT
!$OMP END PARALLEL
N_double = 0
e_corr = 0.d0
e_corr_double = 0.d0
do i = 1, sze
call get_excitation_degree(ref_bitmask,dets_in(1,1,i),degree,Nint)
degree_exc(i) = degree+1
if(degree==0)then
index_hf=i
else if (degree == 2)then
N_double += 1
index_double(N_double) = i
doubles(:,:,N_double) = dets_in(:,:,i)
call i_H_j(ref_bitmask,dets_in(1,1,i),Nint,hij_elec)
hij_double(N_double) = hij_elec
e_corr_array(N_double) = u_in(i,1)* hij_elec
e_corr_double += e_corr_array(N_double)
e_corr += e_corr_array(N_double)
else if (degree == 1)then
call i_H_j(ref_bitmask,dets_in(1,1,i),Nint,hij_elec)
e_corr += u_in(i,1)* hij_elec
endif
enddo
inv_c0 = 1.d0/u_in(index_hf,1)
do i = 1, N_double
e_corr_array(i) = e_corr_array(i) * inv_c0
enddo
e_corr = e_corr * inv_c0
e_corr_double = e_corr_double * inv_c0
converged = .False.
e_corr_double_before = e_corr_double
iter = 0
do while (.not.converged)
iter +=1
!$OMP PARALLEL DEFAULT(NONE) &
!$OMP PRIVATE(i,j,degree,accu) &
!$OMP SHARED(H_jj_dressed,sze,H_jj_ref,index_hf,N_int,N_double,&
!$OMP dets_in,doubles,degree_exc,e_corr_array,e_corr_double)
!$OMP DO SCHEDULE(STATIC)
do i=1,sze
H_jj_dressed(i) = H_jj_ref(i)
if (i==index_hf)cycle
accu = -e_corr_double
select case (N_int)
case (1)
do j=1,N_double
degree = &
popcnt(xor( dets_in(1,1,i),doubles(1,1,j))) + &
popcnt(xor( dets_in(1,2,i),doubles(1,2,j)))
if (degree<=ishft(degree_exc(i),1)) then
accu += e_corr_array(j)
endif
enddo
case (2)
do j=1,N_double
degree = &
popcnt(xor( dets_in(1,1,i),doubles(1,1,j))) + &
popcnt(xor( dets_in(1,2,i),doubles(1,2,j))) + &
popcnt(xor( dets_in(2,1,i),doubles(2,1,j))) + &
popcnt(xor( dets_in(2,2,i),doubles(2,2,j)))
if (degree<=ishft(degree_exc(i),1)) then
accu += e_corr_array(j)
endif
enddo
case (3)
do j=1,N_double
degree = &
popcnt(xor( dets_in(1,1,i),doubles(1,1,j))) + &
popcnt(xor( dets_in(1,2,i),doubles(1,2,j))) + &
popcnt(xor( dets_in(2,1,i),doubles(2,1,j))) + &
popcnt(xor( dets_in(2,2,i),doubles(2,2,j))) + &
popcnt(xor( dets_in(3,1,i),doubles(3,1,j))) + &
popcnt(xor( dets_in(3,2,i),doubles(3,2,j)))
if (degree<=ishft(degree_exc(i),1)) then
accu += e_corr_array(j)
endif
enddo
case default
do j=1,N_double
call get_excitation_degree(dets_in(1,1,i),doubles(1,1,j),degree,N_int)
if (degree<=degree_exc(i)) then
accu += e_corr_array(j)
endif
enddo
end select
H_jj_dressed(i) -= accu
enddo
!$OMP END DO
!$OMP END PARALLEL
if(sze<=N_det_max_jacobi)then
double precision, allocatable :: eigenvectors(:,:), eigenvalues(:),H_matrix_tmp(:,:)
allocate (H_matrix_tmp(size(H_matrix_all_dets,1),sze),eigenvalues(sze),eigenvectors(size(H_matrix_all_dets,1),sze))
do j=1,sze
do i=1,sze
H_matrix_tmp(i,j) = H_matrix_all_dets(i,j)
enddo
enddo
do i = 1,sze
H_matrix_tmp(i,i) = H_jj_dressed(i)
enddo
call lapack_diag(eigenvalues,eigenvectors, &
H_matrix_tmp,size(H_matrix_all_dets,1),sze)
do j=1,min(N_states_diag,sze)
do i=1,sze
u_in(i,j) = eigenvectors(i,j)
enddo
energies(j) = eigenvalues(j)
enddo
deallocate (H_matrix_tmp, eigenvalues, eigenvectors)
else
call davidson_diag_hjj(dets_in,u_in,H_jj_dressed,energies,dim_in,sze,N_st,N_states_diag,Nint,6)
endif
e_corr_double = 0.d0
inv_c0 = 1.d0/u_in(index_hf,1)
do i = 1, N_double
e_corr_array(i) = u_in(index_double(i),1)*inv_c0 * hij_double(i)
e_corr_double += e_corr_array(i)
enddo
write(6,'(A,I3)') 'SC2 Iteration ', iter
write(6,'(A)') '------------------'
write(6,'(A)') ''
write(6,'(A)') '===== ================'
write(6,'(A)') 'State Energy '
write(6,'(A)') '===== ================'
do i=1,N_st
write(6,'(I5,1X,F16.10)') i, energies(i)+nuclear_repulsion
enddo
write(6,'(A)') '===== ================'
write(6,'(A)') ''
call write_double(6,(e_corr_double - e_corr_double_before),&
'Delta(E_corr)')
converged = dabs(e_corr_double - e_corr_double_before) < convergence
converged = converged
if (converged) then
do i = 1, dim_in
diag_H_elements(i) = H_jj_dressed(i) - H_jj_ref(i)
enddo
exit
endif
e_corr_double_before = e_corr_double
enddo
call write_time(6)
deallocate (doubles,e_corr_array,H_jj_ref,H_jj_dressed, &
index_double, degree_exc, hij_double)
end