subroutine give_2h1p_contrib(matrix_2h1p) use bitmasks implicit none double precision , intent(inout) :: matrix_2h1p(N_det,N_det,*) integer :: i,j,r,a,b integer :: iorb, jorb, rorb, aorb, borb integer :: ispin,jspin integer :: idet,jdet integer(bit_kind) :: perturb_dets(N_int,2,n_act_orb,2,2) double precision :: perturb_dets_phase(n_act_orb,2,2) double precision :: perturb_dets_hij(n_act_orb,2,2) double precision :: coef_perturb_from_idet(n_act_orb,2,2,N_states) integer :: inint integer :: elec_num_tab_local(2),acu_elec integer(bit_kind) :: det_tmp(N_int,2) integer :: exc(0:2,2,2) integer :: accu_elec double precision :: get_mo_bielec_integral_schwartz double precision :: active_int(n_act_orb,2) double precision :: hij,phase !matrix_2h1p = 0.d0 elec_num_tab_local = 0 do inint = 1, N_int elec_num_tab_local(1) += popcnt(psi_det(inint,1,1)) elec_num_tab_local(2) += popcnt(psi_det(inint,2,1)) enddo do i = 1, n_inact_orb ! First inactive iorb = list_inact(i) do j = 1, n_inact_orb ! Second inactive jorb = list_inact(j) do r = 1, n_virt_orb ! First virtual rorb = list_virt(r) ! take all the integral you will need for i,j,r fixed do a = 1, n_act_orb aorb = list_act(a) active_int(a,1) = get_mo_bielec_integral_schwartz(iorb,jorb,rorb,aorb,mo_integrals_map) ! direct active_int(a,2) = get_mo_bielec_integral_schwartz(iorb,jorb,aorb,rorb,mo_integrals_map) ! exchange enddo integer :: degree(N_det) integer :: idx(0:N_det) double precision :: delta_e(n_act_orb,2,N_states) integer :: istate integer :: index_orb_act_mono(N_det,3) do idet = 1, N_det call get_excitation_degree_vector_mono(psi_det,psi_det(1,1,idet),degree,N_int,N_det,idx) !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Precomputation of matrix elements do ispin = 1, 2 ! spin of the couple a-a^dagger (i,r) do jspin = 1, 2 ! spin of the couple z-a^dagger (j,a) if(ispin == jspin .and. iorb.le.jorb)cycle ! condition not to double count do a = 1, n_act_orb ! First active aorb = list_act(a) do inint = 1, N_int det_tmp(inint,1) = psi_det(inint,1,idet) det_tmp(inint,2) = psi_det(inint,2,idet) enddo ! Do the excitation inactive -- > virtual call clear_bit_to_integer(iorb,det_tmp(1,ispin),N_int) ! hole in "iorb" of spin Ispin call set_bit_to_integer(rorb,det_tmp(1,ispin),N_int) ! particle in "rorb" of spin Ispin ! Do the excitation inactive -- > active call clear_bit_to_integer(jorb,det_tmp(1,jspin),N_int) ! hole in "jorb" of spin Jspin call set_bit_to_integer(aorb,det_tmp(1,jspin),N_int) ! particle in "aorb" of spin Jspin ! Check if the excitation is possible or not on psi_det(idet) accu_elec= 0 do inint = 1, N_int accu_elec+= popcnt(det_tmp(inint,jspin)) enddo if(accu_elec .ne. elec_num_tab_local(jspin))then perturb_dets_phase(a,jspin,ispin) = 0.0 perturb_dets_hij(a,jspin,ispin) = 0.d0 do istate = 1, N_states coef_perturb_from_idet(a,jspin,ispin,istate) = 0.d0 enddo cycle endif do inint = 1, N_int perturb_dets(inint,1,a,jspin,ispin) = det_tmp(inint,1) perturb_dets(inint,2,a,jspin,ispin) = det_tmp(inint,2) enddo call get_double_excitation(psi_det(1,1,idet),det_tmp,exc,phase,N_int) perturb_dets_phase(a,jspin,ispin) = phase do istate = 1, N_states delta_e(a,jspin,istate) = one_creat(a,jspin,istate) & - fock_virt_total_spin_trace(rorb,istate) & + fock_core_inactive_total_spin_trace(iorb,istate) & + fock_core_inactive_total_spin_trace(jorb,istate) enddo if(ispin == jspin)then perturb_dets_hij(a,jspin,ispin) = phase * (active_int(a,2) - active_int(a,1) ) else perturb_dets_hij(a,jspin,ispin) = phase * active_int(a,1) endif !!!!!!!!!!!!!!!!!!!!!1 Computation of the coefficient at first order coming from idet !!!!!!!!!!!!!!!!!!!!! for the excitation (i,j)(ispin,jspin) ---> (r,a)(ispin,jspin) do istate = 1, N_states coef_perturb_from_idet(a,jspin,ispin,istate) = perturb_dets_hij(a,jspin,ispin) / delta_e(a,jspin,istate) enddo enddo enddo enddo !!!!!!!!!!!!!!!!!!!!!!!!!!! determination of the connections between I and the other J determinants mono excited in the CAS !!!!!!!!!!!!!!!!!!!!!!!!!!!! the determinants I and J must be connected by the following operator !!!!!!!!!!!!!!!!!!!!!!!!!!!! do jdet = 1, idx(0) if(idx(jdet).ne.idet)then call get_mono_excitation(psi_det(1,1,idet),psi_det(1,1,idx(jdet)),exc,phase,N_int) if (exc(0,1,1) == 1) then ! Mono alpha index_orb_act_mono(idx(jdet),1) = list_act_reverse(exc(1,2,1)) !!! a^{\dagger}_a index_orb_act_mono(idx(jdet),2) = list_act_reverse(exc(1,1,1)) !!! a_{b} index_orb_act_mono(idx(jdet),3) = 1 else ! Mono beta index_orb_act_mono(idx(jdet),1) = list_act_reverse(exc(1,2,2)) !!! a^{\dagger}_a index_orb_act_mono(idx(jdet),2) = list_act_reverse(exc(1,1,2)) !!! a_{b} index_orb_act_mono(idx(jdet),3) = 2 endif else index_orb_act_mono(idx(jdet),1) = -1 endif enddo integer :: kspin do jdet = 1, idx(0) if(idx(jdet).ne.idet)then ! two determinants | Idet > and | Jdet > which are connected throw a mono excitation operator ! are connected by the presence of the perturbers determinants |det_tmp> aorb = index_orb_act_mono(idx(jdet),1) ! a^{\dagger}_{aorb} borb = index_orb_act_mono(idx(jdet),2) ! a_{borb} kspin = index_orb_act_mono(idx(jdet),3) ! spin of the excitation ! the determinants Idet and Jdet interact throw the following operator ! | Jdet > = a_{borb,kspin} a^{\dagger}_{aorb, kspin} | Idet > do ispin = 1, 2 ! you loop on all possible spin for the excitation ! a^{\dagger}_r a_{i} (ispin) if(ispin == kspin .and. iorb.le.jorb)cycle ! condition not to double count ! | det_tmp > = a^{\dagger}_{rorb,ispin} a^{\dagger}_{aorb,kspin} a_{jorb,kspin} a_{iorb,ispin} | Idet > do inint = 1, N_int det_tmp(inint,1) = perturb_dets(inint,1,aorb,kspin,ispin) det_tmp(inint,2) = perturb_dets(inint,2,aorb,kspin,ispin) enddo double precision :: hja ! you determine the interaction between the excited determinant and the other parent | Jdet > ! | det_tmp > = a^{\dagger}_{rorb,ispin} a^{\dagger}_{borb,kspin} a_{jorb,kspin} a_{iorb,ispin} | Jdet > ! hja = < det_tmp | H | Jdet > call get_double_excitation(psi_det(1,1,idx(jdet)),det_tmp,exc,phase,N_int) if(kspin == ispin)then hja = phase * (active_int(borb,2) - active_int(borb,1) ) else hja = phase * active_int(borb,1) endif do istate = 1, N_states matrix_2h1p(idx(jdet),idet,istate) += hja * coef_perturb_from_idet(aorb,kspin,ispin,istate) enddo enddo ! ispin else ! diagonal part of the dressing : interaction of | Idet > with all the perturbers generated by the excitations ! ! | det_tmp > = a^{\dagger}_{rorb,ispin} a^{\dagger}_{aorb,kspin} a_{jorb,kspin} a_{iorb,ispin} | Idet > do ispin = 1, 2 do kspin = 1, 2 if(ispin == kspin .and. iorb.le.jorb)cycle ! condition not to double count do a = 1, n_act_orb ! First active do istate = 1, N_states matrix_2h1p(idet,idet,istate) += coef_perturb_from_idet(a,kspin,ispin,istate) * perturb_dets_hij(a,kspin,ispin) enddo enddo enddo enddo endif enddo enddo enddo enddo enddo end subroutine give_1h2p_contrib(matrix_1h2p) use bitmasks implicit none double precision , intent(inout) :: matrix_1h2p(N_det,N_det,*) integer :: i,v,r,a,b integer :: iorb, vorb, rorb, aorb, borb integer :: ispin,jspin integer :: idet,jdet integer(bit_kind) :: perturb_dets(N_int,2,n_act_orb,2,2) double precision :: perturb_dets_phase(n_act_orb,2,2) double precision :: perturb_dets_hij(n_act_orb,2,2) double precision :: coef_perturb_from_idet(n_act_orb,2,2,N_states) integer :: inint integer :: elec_num_tab_local(2),acu_elec integer(bit_kind) :: det_tmp(N_int,2) integer :: exc(0:2,2,2) integer :: accu_elec double precision :: get_mo_bielec_integral_schwartz double precision :: active_int(n_act_orb,2) double precision :: hij,phase !matrix_1h2p = 0.d0 elec_num_tab_local = 0 do inint = 1, N_int elec_num_tab_local(1) += popcnt(psi_det(inint,1,1)) elec_num_tab_local(2) += popcnt(psi_det(inint,2,1)) enddo do i = 1, n_inact_orb ! First inactive iorb = list_inact(i) do v = 1, n_virt_orb ! First virtual vorb = list_virt(v) do r = 1, n_virt_orb ! Second virtual rorb = list_virt(r) ! take all the integral you will need for i,j,r fixed do a = 1, n_act_orb aorb = list_act(a) active_int(a,1) = get_mo_bielec_integral_schwartz(iorb,aorb,rorb,vorb,mo_integrals_map) ! direct active_int(a,2) = get_mo_bielec_integral_schwartz(iorb,aorb,vorb,rorb,mo_integrals_map) ! exchange enddo integer :: degree(N_det) integer :: idx(0:N_det) double precision :: delta_e(n_act_orb,2,N_states) integer :: istate integer :: index_orb_act_mono(N_det,3) do idet = 1, N_det call get_excitation_degree_vector_mono(psi_det,psi_det(1,1,idet),degree,N_int,N_det,idx) !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Precomputation of matrix elements do ispin = 1, 2 ! spin of the couple a-a^dagger (iorb,rorb) do jspin = 1, 2 ! spin of the couple a-a^dagger (aorb,vorb) do a = 1, n_act_orb ! First active aorb = list_act(a) if(ispin == jspin .and. vorb.le.rorb)cycle ! condition not to double count do inint = 1, N_int det_tmp(inint,1) = psi_det(inint,1,idet) det_tmp(inint,2) = psi_det(inint,2,idet) enddo ! Do the excitation inactive -- > virtual call clear_bit_to_integer(iorb,det_tmp(1,ispin),N_int) ! hole in "iorb" of spin Ispin call set_bit_to_integer(rorb,det_tmp(1,ispin),N_int) ! particle in "rorb" of spin Ispin ! Do the excitation active -- > virtual call clear_bit_to_integer(aorb,det_tmp(1,jspin),N_int) ! hole in "aorb" of spin Jspin call set_bit_to_integer(vorb,det_tmp(1,jspin),N_int) ! particle in "vorb" of spin Jspin ! Check if the excitation is possible or not on psi_det(idet) accu_elec= 0 do inint = 1, N_int accu_elec+= popcnt(det_tmp(inint,jspin)) enddo if(accu_elec .ne. elec_num_tab_local(jspin))then perturb_dets_phase(a,jspin,ispin) = 0.0 perturb_dets_hij(a,jspin,ispin) = 0.d0 do istate = 1, N_states coef_perturb_from_idet(a,jspin,ispin,istate) = 0.d0 enddo cycle endif do inint = 1, N_int perturb_dets(inint,1,a,jspin,ispin) = det_tmp(inint,1) perturb_dets(inint,2,a,jspin,ispin) = det_tmp(inint,2) enddo do inint = 1, N_int det_tmp(inint,1) = perturb_dets(inint,1,a,jspin,ispin) det_tmp(inint,2) = perturb_dets(inint,2,a,jspin,ispin) enddo call get_double_excitation(psi_det(1,1,idet),det_tmp,exc,phase,N_int) perturb_dets_phase(a,jspin,ispin) = phase do istate = 1, N_states delta_e(a,jspin,istate) = one_anhil(a,jspin,istate) & - fock_virt_total_spin_trace(rorb,istate) & - fock_virt_total_spin_trace(vorb,istate) & + fock_core_inactive_total_spin_trace(iorb,istate) enddo if(ispin == jspin)then perturb_dets_hij(a,jspin,ispin) = phase * (active_int(a,1) - active_int(a,2) ) else perturb_dets_hij(a,jspin,ispin) = phase * active_int(a,1) endif !!!!!!!!!!!!!!!!!!!!!1 Computation of the coefficient at first order coming from idet !!!!!!!!!!!!!!!!!!!!! for the excitation (i,j)(ispin,jspin) ---> (r,a)(ispin,jspin) do istate = 1, N_states coef_perturb_from_idet(a,jspin,ispin,istate) = perturb_dets_hij(a,jspin,ispin) / delta_e(a,jspin,istate) enddo enddo enddo enddo !!!!!!!!!!!!!!!!!!!!!!!!!!! determination of the connections between I and the other J determinants mono excited in the CAS !!!!!!!!!!!!!!!!!!!!!!!!!!!! the determinants I and J must be connected by the following operator !!!!!!!!!!!!!!!!!!!!!!!!!!!! do jdet = 1, idx(0) if(idx(jdet).ne.idet)then call get_mono_excitation(psi_det(1,1,idet),psi_det(1,1,idx(jdet)),exc,phase,N_int) if (exc(0,1,1) == 1) then ! Mono alpha index_orb_act_mono(idx(jdet),1) = list_act_reverse(exc(1,1,1)) !!! a_a index_orb_act_mono(idx(jdet),2) = list_act_reverse(exc(1,2,1)) !!! a^{\dagger}_{b} index_orb_act_mono(idx(jdet),3) = 1 else ! Mono beta index_orb_act_mono(idx(jdet),1) = list_act_reverse(exc(1,1,2)) !!! a_a index_orb_act_mono(idx(jdet),2) = list_act_reverse(exc(1,2,2)) !!! a^{\dagger}_{b} index_orb_act_mono(idx(jdet),3) = 2 endif else index_orb_act_mono(idx(jdet),1) = -1 endif enddo integer :: kspin do jdet = 1, idx(0) if(idx(jdet).ne.idet)then ! two determinants | Idet > and | Jdet > which are connected throw a mono excitation operator ! are connected by the presence of the perturbers determinants |det_tmp> aorb = index_orb_act_mono(idx(jdet),1) ! a_{aorb} borb = index_orb_act_mono(idx(jdet),2) ! a^{\dagger}_{borb} kspin = index_orb_act_mono(idx(jdet),3) ! spin of the excitation ! the determinants Idet and Jdet interact throw the following operator ! | Jdet > = a^{\dagger}_{borb,kspin} a_{aorb, kspin} | Idet > do ispin = 1, 2 ! you loop on all possible spin for the excitation ! a^{\dagger}_r a_{i} (ispin) if(ispin == kspin .and. vorb.le.rorb)cycle ! condition not to double count ! | det_tmp > = a^{\dagger}_{rorb,ispin} a^{\dagger}_{vorb,kspin} a_{aorb,kspin} a_{iorb,ispin} | Idet > do inint = 1, N_int det_tmp(inint,1) = perturb_dets(inint,1,aorb,kspin,ispin) det_tmp(inint,2) = perturb_dets(inint,2,aorb,kspin,ispin) enddo double precision :: hja ! you determine the interaction between the excited determinant and the other parent | Jdet > ! | det_tmp > = a^{\dagger}_{rorb,ispin} a^{\dagger}_{vorb,kspin} a_{borb,kspin} a_{iorb,ispin} | Jdet > ! hja = < det_tmp | H | Jdet > call get_double_excitation(psi_det(1,1,idx(jdet)),det_tmp,exc,phase,N_int) if(kspin == ispin)then hja = phase * (active_int(borb,1) - active_int(borb,2) ) else hja = phase * active_int(borb,1) endif do istate = 1, N_states matrix_1h2p(idx(jdet),idet,istate) += hja * coef_perturb_from_idet(aorb,kspin,ispin,istate) enddo enddo ! ispin else ! diagonal part of the dressing : interaction of | Idet > with all the perturbers generated by the excitations ! ! | det_tmp > = a^{\dagger}_{rorb,ispin} a^{\dagger}_{vorb,kspin} a_{aorb,kspin} a_{iorb,ispin} | Idet > do ispin = 1, 2 do kspin = 1, 2 do a = 1, n_act_orb ! First active aorb = list_act(a) if(ispin == kspin .and. vorb.le.rorb)cycle ! condition not to double count do istate = 1, N_states matrix_1h2p(idet,idet,istate) += coef_perturb_from_idet(a,kspin,ispin,istate) * perturb_dets_hij(a,kspin,ispin) enddo enddo enddo enddo endif enddo enddo enddo enddo enddo end