BEGIN_TEMPLATE subroutine pt2_epstein_nesbet ($arguments) use bitmasks implicit none $declarations BEGIN_DOC ! Compute the standard Epstein-Nesbet perturbative first order coefficient and ! second order energetic contribution for the various N_st states. ! ! `c_pert(i)` = $\\frac{\langle i|H|\\alpha \\rangle}{ E_n - \\langle \\alpha|H|\\alpha \\rangle }$. ! ! `e_2_pert(i)` = $\\frac{\\langle i|H|\\alpha \\rangle^2}{ E_n - \\langle \\alpha|H|\\alpha \\rangle }$. ! END_DOC integer :: i,j double precision :: diag_H_mat_elem_fock, h double precision :: i_H_psi_array(N_st) PROVIDE selection_criterion ASSERT (Nint == N_int) ASSERT (Nint > 0) !call i_H_psi(det_pert,psi_selectors,psi_selectors_coef,Nint,N_det_selectors,psi_selectors_size,N_st,i_H_psi_array) 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) h = diag_H_mat_elem_fock(det_ref,det_pert,fock_diag_tmp,Nint) do i =1,N_st if(electronic_energy(i)>h.and.electronic_energy(i).ne.0.d0)then c_pert(i) = -1.d0 e_2_pert(i) = selection_criterion*selection_criterion_factor*2.d0 else if (dabs(electronic_energy(i) - h) > 1.d-6) then c_pert(i) = i_H_psi_array(i) / (electronic_energy(i) - h) H_pert_diag(i) = h*c_pert(i)*c_pert(i) e_2_pert(i) = c_pert(i) * i_H_psi_array(i) else c_pert(i) = -1.d0 e_2_pert(i) = -dabs(i_H_psi_array(i)) H_pert_diag(i) = h endif enddo end subroutine pt2_qdpt ($arguments) use bitmasks implicit none $declarations BEGIN_DOC ! Computes the QDPT first order coefficient and second order energetic contribution ! for the various N_st states. ! ! `c_pert(i)` = $\\frac{\\langle i|H|\\alpha \\rangle}{\\langle i|H|i \\rangle - \\langle \\alpha|H|\\alpha \\rangle}$. ! END_DOC integer :: i,j double precision :: diag_H_mat_elem_fock, h, E, diag_H_mat_elem, hij double precision :: i_H_psi_array(N_st) integer :: degree double precision :: delta_E PROVIDE selection_criterion ASSERT (Nint == N_int) ASSERT (Nint > 0) !call i_H_psi(det_pert,psi_selectors,psi_selectors_coef,Nint,N_det_selectors,psi_selectors_size,N_st,i_H_psi_array) 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) h = diag_H_mat_elem_fock(det_ref,det_pert,fock_diag_tmp,Nint) c_pert = 0.d0 do j=1,N_det_selectors call get_excitation_degree(det_ref, psi_selectors(1,1,j), degree, Nint) if (degree > 2) then E = diag_H_mat_elem(psi_selectors(1,1,j),Nint) else E = diag_H_mat_elem_fock(det_ref,det_ref,fock_diag_tmp,Nint) endif delta_E = E-h ! delta_E = electronic_energy(1) - h call i_H_j(psi_selectors(1,1,j),det_pert,Nint,hij) if (dabs(delta_e) > 1.d-3) then do i =1,N_st c_pert(i) += psi_selectors_coef(j,i) * hij / delta_e enddo endif enddo do i =1,N_st e_2_pert(i) = c_pert(i)*i_H_psi_array(i) H_pert_diag(i) = h*c_pert(i)*c_pert(i) enddo end subroutine pt2_epstein_nesbet_2x2 ($arguments) use bitmasks implicit none $declarations BEGIN_DOC ! Computes the Epstein-Nesbet 2x2 diagonalization coefficient and energetic contribution ! for the various N_st states. ! ! `e_2_pert(i)` = $\\frac{1}{2} ( \\langle \\alpha|H|\\alpha \\rangle - E_n) - \\sqrt{ (\\langle \\alpha|H|\\alpha \\rangle - E_n)^2 + 4 \\langle i|H|\\alpha \\rangle^2 }$. ! ! `c_pert(i)` = `e_2_pert(i)` $\\times \\frac{1}{ \\langle i|H|\\alpha \\rangle}$. ! END_DOC integer :: i,j double precision :: diag_H_mat_elem_fock,delta_e, h double precision :: i_H_psi_array(N_st) ASSERT (Nint == N_int) ASSERT (Nint > 0) call i_H_psi(det_pert,psi_selectors,psi_selectors_coef,Nint,N_det_selectors,psi_selectors_size,N_st,i_H_psi_array) !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) h = diag_H_mat_elem_fock(det_ref,det_pert,fock_diag_tmp,Nint) do i =1,N_st if (i_H_psi_array(i) /= 0.d0) then delta_e = h - electronic_energy(i) if (delta_e > 0.d0) then 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))) else 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))) endif if (dabs(i_H_psi_array(i)) > 1.d-6) then c_pert(i) = e_2_pert(i)/i_H_psi_array(i) else c_pert(i) = 0.d0 endif H_pert_diag(i) = h*c_pert(i)*c_pert(i) else e_2_pert(i) = 0.d0 c_pert(i) = 0.d0 H_pert_diag(i) = 0.d0 endif enddo end subroutine pt2_epstein_nesbet_2x2_no_ci_diag($arguments) use bitmasks implicit none $declarations BEGIN_DOC ! compute the Epstein-Nesbet 2x2 diagonalization coefficient and energetic contribution ! ! for the various N_st states. ! ! e_2_pert(i) = 0.5 * (( - E(i) ) - sqrt( ( - E(i)) ^2 + 4 ^2 ) ! ! c_pert(i) = e_2_pert(i)/ ! END_DOC integer :: i,j double precision :: diag_H_mat_elem_fock,delta_e, h double precision :: i_H_psi_array(N_st) ASSERT (Nint == N_int) ASSERT (Nint > 0) PROVIDE psi_energy call i_H_psi(det_pert,psi_selectors,psi_selectors_coef,Nint,N_det_selectors,psi_selectors_size,N_st,i_H_psi_array) h = diag_H_mat_elem_fock(det_ref,det_pert,fock_diag_tmp,Nint) do i =1,N_st if (i_H_psi_array(i) /= 0.d0) then delta_e = h - psi_energy(i) if (delta_e > 0.d0) then e_2_pert(i) = 0.5d0 * (delta_e - dsqrt(delta_e * delta_e + 4.d0 * i_H_psi_array(i) * i_H_psi_array(i))) else e_2_pert(i) = 0.5d0 * (delta_e + dsqrt(delta_e * delta_e + 4.d0 * i_H_psi_array(i) * i_H_psi_array(i))) endif if (dabs(i_H_psi_array(i)) > 1.d-6) then c_pert(i) = e_2_pert(i)/i_H_psi_array(i) else c_pert(i) = 0.d0 endif H_pert_diag(i) = h*c_pert(i)*c_pert(i) else e_2_pert(i) = 0.d0 c_pert(i) = 0.d0 H_pert_diag(i) = 0.d0 endif enddo end subroutine pt2_moller_plesset ($arguments) use bitmasks implicit none $declarations BEGIN_DOC ! Computes the standard Moller-Plesset perturbative first order coefficient and second ! order energetic contribution for the various N_st states. ! ! `c_pert(i)` = $\\frac{\\langle i|H|\\alpha \\rangle}{\\text{difference of orbital energies}}$. ! ! `e_2_pert(i)` = $\\frac{\\langle i|H|\\alpha \\rangle^2}{\\text{difference of orbital energies}}$. ! END_DOC integer :: i,j double precision :: diag_H_mat_elem_fock integer :: exc(0:2,2,2) integer :: degree double precision :: phase,delta_e,h double precision :: i_H_psi_array(N_st) integer :: h1,h2,p1,p2,s1,s2 ASSERT (Nint == N_int) ASSERT (Nint > 0) call get_excitation(ref_bitmask,det_pert,exc,degree,phase,Nint) if (degree == 2) then call decode_exc(exc,degree,h1,p1,h2,p2,s1,s2) delta_e = (Fock_matrix_diag_mo(h1) - Fock_matrix_diag_mo(p1)) + & (Fock_matrix_diag_mo(h2) - Fock_matrix_diag_mo(p2)) else if (degree == 1) then call decode_exc(exc,degree,h1,p1,h2,p2,s1,s2) delta_e = Fock_matrix_diag_mo(h1) - Fock_matrix_diag_mo(p1) else delta_e = 0.d0 endif if (dabs(delta_e) > 1.d-10) then delta_e = 1.d0/delta_e 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) h = diag_H_mat_elem_fock(det_ref,det_pert,fock_diag_tmp,Nint) else i_H_psi_array(:) = 0.d0 h = 0.d0 endif do i =1,N_st H_pert_diag(i) = h c_pert(i) = i_H_psi_array(i) *delta_e e_2_pert(i) = c_pert(i) * i_H_psi_array(i) enddo end subroutine pt2_dummy ($arguments) use bitmasks implicit none $declarations BEGIN_DOC ! Dummy perturbation to add all connected determinants. END_DOC integer :: i,j double precision :: diag_H_mat_elem_fock, h double precision :: i_H_psi_array(N_st) PROVIDE selection_criterion 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) h = diag_H_mat_elem_fock(det_ref,det_pert,fock_diag_tmp,Nint) do i =1,N_st if (i_H_psi_array(i) /= 0.d0) then c_pert(i) = i_H_psi_array(i) / (electronic_energy(i) - h) H_pert_diag(i) = h*c_pert(i)*c_pert(i) e_2_pert(i) = 1.d0 else c_pert(i) = 0.d0 e_2_pert(i) = 0.d0 H_pert_diag(i) = 0.d0 endif enddo end SUBST [ arguments, declarations ] electronic_energy,det_ref,det_pert,fock_diag_tmp,c_pert,e_2_pert,H_pert_diag,Nint,ndet,N_st,minilist,idx_minilist,N_minilist ; integer, intent(in) :: Nint integer, intent(in) :: ndet integer, intent(in) :: N_st integer, intent(in) :: N_minilist integer(bit_kind), intent(in) :: det_ref (Nint,2) integer(bit_kind), intent(in) :: det_pert(Nint,2) double precision , intent(in) :: fock_diag_tmp(2,mo_num+1) double precision , intent(in) :: electronic_energy(N_st) double precision , intent(out) :: c_pert(N_st) double precision , intent(out) :: e_2_pert(N_st) double precision, intent(out) :: H_pert_diag(N_st) integer, intent(in) :: idx_minilist(0:N_det_selectors) integer(bit_kind), intent(in) :: minilist(Nint,2,N_det_selectors) ;; END_TEMPLATE ! Note : If the arguments are changed here, they should also be changed accordingly in ! the perturbation.template.f file.