mirror of
https://github.com/LCPQ/quantum_package
synced 2024-08-16 01:28:39 +02:00
165 lines
5.3 KiB
Fortran
165 lines
5.3 KiB
Fortran
BEGIN_TEMPLATE
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subroutine pt2_epstein_nesbet ($arguments)
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use bitmasks
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implicit none
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$declarations
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BEGIN_DOC
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! compute the standard Epstein-Nesbet perturbative first order coefficient and second order energetic contribution
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!
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! for the various N_st states.
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!
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! c_pert(i) = <psi(i)|H|det_pert>/( E(i) - <det_pert|H|det_pert> )
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!
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! e_2_pert(i) = <psi(i)|H|det_pert>^2/( E(i) - <det_pert|H|det_pert> )
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!
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END_DOC
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integer :: i,j
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double precision :: diag_H_mat_elem, h
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double precision :: i_H_psi_array(N_st)
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PROVIDE selection_criterion
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ASSERT (Nint == N_int)
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ASSERT (Nint > 0)
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!call i_H_psi(det_pert,psi_selectors,psi_selectors_coef,Nint,N_det_selectors,psi_selectors_size,N_st,i_H_psi_array)
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call i_H_psi_minilist(det_pert,minilist,idx_minilist,N_minilist,psi_selectors_coef,Nint,N_minilist,psi_selectors_size,N_st,i_H_psi_array)
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h = diag_H_mat_elem(det_pert,Nint)
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do i =1,N_st
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if(CI_electronic_energy(i)>h.and.CI_electronic_energy(i).ne.0.d0)then
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c_pert(i) = -1.d0
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e_2_pert(i) = selection_criterion*selection_criterion_factor*2.d0
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else if (dabs(CI_electronic_energy(i) - h) > 1.d-6) then
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c_pert(i) = i_H_psi_array(i) / (CI_electronic_energy(i) - h)
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H_pert_diag(i) = h*c_pert(i)*c_pert(i)
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e_2_pert(i) = c_pert(i) * i_H_psi_array(i)
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else
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c_pert(i) = -1.d0
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e_2_pert(i) = -dabs(i_H_psi_array(i))
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H_pert_diag(i) = h
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endif
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enddo
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end
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subroutine pt2_epstein_nesbet_2x2 ($arguments)
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use bitmasks
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implicit none
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$declarations
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BEGIN_DOC
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! compute the Epstein-Nesbet 2x2 diagonalization coefficient and energetic contribution
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!
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! for the various N_st states.
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!
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! e_2_pert(i) = 0.5 * (( <det_pert|H|det_pert> - E(i) ) - sqrt( ( <det_pert|H|det_pert> - E(i)) ^2 + 4 <psi(i)|H|det_pert>^2 )
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!
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! c_pert(i) = e_2_pert(i)/ <psi(i)|H|det_pert>
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!
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END_DOC
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integer :: i,j
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double precision :: diag_H_mat_elem,delta_e, h
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double precision :: i_H_psi_array(N_st)
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ASSERT (Nint == N_int)
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ASSERT (Nint > 0)
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PROVIDE CI_electronic_energy
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!call i_H_psi(det_pert,psi_selectors,psi_selectors_coef,Nint,N_det_selectors,psi_selectors_size,N_st,i_H_psi_array)
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call i_H_psi_minilist(det_pert,minilist,idx_minilist,N_minilist,psi_selectors_coef,Nint,N_minilist,psi_selectors_size,N_st,i_H_psi_array)
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h = diag_H_mat_elem(det_pert,Nint)
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do i =1,N_st
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if (i_H_psi_array(i) /= 0.d0) then
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delta_e = h - CI_electronic_energy(i)
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if (delta_e > 0.d0) then
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e_2_pert(i) = 0.5d0 * (delta_e - dsqrt(delta_e * delta_e + 4.d0 * i_H_psi_array(i) * i_H_psi_array(i)))
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else
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e_2_pert(i) = 0.5d0 * (delta_e + dsqrt(delta_e * delta_e + 4.d0 * i_H_psi_array(i) * i_H_psi_array(i)))
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endif
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if (dabs(i_H_psi_array(i)) > 1.d-6) then
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c_pert(i) = e_2_pert(i)/i_H_psi_array(i)
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else
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c_pert(i) = 0.d0
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endif
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H_pert_diag(i) = h*c_pert(i)*c_pert(i)
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else
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e_2_pert(i) = 0.d0
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c_pert(i) = 0.d0
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H_pert_diag(i) = 0.d0
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endif
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enddo
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end
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subroutine pt2_moller_plesset ($arguments)
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use bitmasks
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implicit none
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$declarations
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BEGIN_DOC
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! compute the standard Moller-Plesset perturbative first order coefficient and second order energetic contribution
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!
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! for the various n_st states.
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!
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! c_pert(i) = <psi(i)|H|det_pert>/(difference of orbital energies)
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!
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! e_2_pert(i) = <psi(i)|H|det_pert>^2/(difference of orbital energies)
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!
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END_DOC
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integer :: i,j
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double precision :: diag_H_mat_elem
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integer :: exc(0:2,2,2)
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integer :: degree
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double precision :: phase,delta_e,h
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double precision :: i_H_psi_array(N_st)
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integer :: h1,h2,p1,p2,s1,s2
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ASSERT (Nint == N_int)
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ASSERT (Nint > 0)
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call get_excitation(ref_bitmask,det_pert,exc,degree,phase,Nint)
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if (degree == 2) then
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call decode_exc(exc,degree,h1,p1,h2,p2,s1,s2)
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delta_e = Fock_matrix_diag_mo(h1) + Fock_matrix_diag_mo(h2) - &
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(Fock_matrix_diag_mo(p1) + Fock_matrix_diag_mo(p2))
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delta_e = 1.d0/delta_e
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else if (degree == 1) then
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call decode_exc(exc,degree,h1,p1,h2,p2,s1,s2)
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delta_e = Fock_matrix_diag_mo(h1) - Fock_matrix_diag_mo(p1)
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delta_e = 1.d0/delta_e
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else
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delta_e = 0.d0
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endif
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call i_H_psi(det_pert,psi_selectors,psi_selectors_coef,Nint,N_det,psi_selectors_size,n_st,i_H_psi_array)
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h = diag_H_mat_elem(det_pert,Nint)
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do i =1,n_st
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H_pert_diag(i) = h
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c_pert(i) = i_H_psi_array(i) *delta_e
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e_2_pert(i) = c_pert(i) * i_H_psi_array(i)
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enddo
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end
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SUBST [ arguments, declarations ]
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det_pert,c_pert,e_2_pert,H_pert_diag,Nint,ndet,N_st,minilist,idx_minilist,N_minilist ;
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integer, intent(in) :: Nint
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integer, intent(in) :: ndet
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integer, intent(in) :: N_st
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integer, intent(in) :: N_minilist
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integer(bit_kind), intent(in) :: det_pert(Nint,2)
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double precision , intent(out) :: c_pert(N_st)
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double precision , intent(out) :: e_2_pert(N_st)
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double precision, intent(out) :: H_pert_diag(N_st)
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integer, intent(in) :: idx_minilist(0:N_det_selectors)
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integer(bit_kind), intent(in) :: minilist(Nint,2,N_det_selectors)
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;;
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END_TEMPLATE
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