46 lines
1.2 KiB
Fortran
46 lines
1.2 KiB
Fortran
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subroutine davidson_diag_sx_mat(N_st, u_in, energies)
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implicit none
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integer, intent(in) :: N_st
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double precision, intent(out) :: u_in(nMonoEx+1,n_states_diag), energies(N_st)
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integer :: i,j,N_st_tmp, dim_in, sze, N_st_diag_in
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integer, allocatable :: list_guess(:)
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double precision, allocatable :: H_jj(:)
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logical :: converged
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N_st_diag_in = n_states_diag
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provide SXmatrix
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sze = nMonoEx+1
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dim_in = sze
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allocate(H_jj(sze), list_guess(sze))
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H_jj(1) = 0.d0
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N_st_tmp = 1
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list_guess(1) = 1
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do j = 2, nMonoEx+1
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H_jj(j) = SXmatrix(j,j)
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if(H_jj(j).lt.0.d0)then
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list_guess(N_st_tmp) = j
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N_st_tmp += 1
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endif
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enddo
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if(N_st_tmp .ne. N_st)then
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print*,'Pb in davidson_diag_sx_mat'
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print*,'N_st_tmp .ne. N_st'
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print*,N_st_tmp, N_st
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stop
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endif
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print*,'Number of possibly interesting states = ',N_st
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print*,'Corresponding diagonal elements of the SX matrix '
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u_in = 0.d0
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do i = 1, min(N_st, N_st_diag_in)
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! do i = 1, N_st
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j = list_guess(i)
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print*,'i,j',i,j
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print*,'SX(i,i) = ',H_jj(j)
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u_in(j,i) = 1.d0
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enddo
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call davidson_general(u_in,H_jj,energies,dim_in,sze,N_st,N_st_diag_in,converged,SXmatrix)
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print*,'energies = ',energies
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end
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