mirror of
https://github.com/LCPQ/quantum_package
synced 2024-08-31 00:23:42 +02:00
78 lines
3.0 KiB
Fortran
78 lines
3.0 KiB
Fortran
subroutine pt2_delta_rho_one_point(det_pert,c_pert,e_2_pert,H_pert_diag,Nint,ndet,n_st,minilist,idx_minilist,N_minilist)
|
|
use bitmasks
|
|
implicit none
|
|
integer, intent(in) :: Nint,ndet,n_st
|
|
integer(bit_kind), intent(in) :: det_pert(Nint,2)
|
|
double precision , intent(out) :: c_pert(n_st),e_2_pert(n_st),H_pert_diag(N_st)
|
|
double precision :: i_O1_psi_array(N_st)
|
|
double precision :: i_H_psi_array(N_st)
|
|
|
|
integer, intent(in) :: N_minilist
|
|
integer, intent(in) :: idx_minilist(0:N_det_selectors)
|
|
integer(bit_kind), intent(in) :: minilist(Nint,2,N_det_selectors)
|
|
|
|
BEGIN_DOC
|
|
! compute the perturbatibe contribution to the Integrated Spin density at z = z_one point of one determinant
|
|
!
|
|
! for the various n_st states, at various level of theory.
|
|
!
|
|
! c_pert(i) = <psi(i)|H|det_pert>/(<psi(i)|H|psi(i)> - <det_pert|H|det_pert>)
|
|
!
|
|
! e_2_pert(i) = c_pert(i) * <det_pert|O|psi(i)>
|
|
!
|
|
! H_pert_diag(i) = c_pert(i)^2 * <det_pert|O|det_pert>
|
|
!
|
|
! To get the contribution of the first order :
|
|
!
|
|
! <O_1> = sum(over i) e_2_pert(i)
|
|
!
|
|
! To get the contribution of the diagonal elements of the second order :
|
|
!
|
|
! [ <O_0> + <O_1> + sum(over i) H_pert_diag(i) ] / [1. + sum(over i) c_pert(i) **2]
|
|
!
|
|
END_DOC
|
|
|
|
integer :: i,j
|
|
double precision :: diag_H_mat_elem,diag_o1_mat_elem_alpha_beta
|
|
integer :: exc(0:2,2,2)
|
|
integer :: degree
|
|
double precision :: phase,delta_e,h,oii,diag_o1_mat_elem
|
|
integer :: h1,h2,p1,p2,s1,s2
|
|
ASSERT (Nint == N_int)
|
|
ASSERT (Nint > 0)
|
|
|
|
! call get_excitation_degree(HF_bitmask,det_pert,degree,N_int)
|
|
! if(degree.gt.degree_max_generators+1)then
|
|
! H_pert_diag = 0.d0
|
|
! e_2_pert = 0.d0
|
|
! c_pert = 0.d0
|
|
! return
|
|
! endif
|
|
call i_O1_psi_alpha_beta(mo_integrated_delta_rho_one_point,det_pert,psi_selectors,psi_selectors_coef,Nint,N_det_selectors,psi_selectors_size,N_st,i_O1_psi_array)
|
|
|
|
!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(det_pert,Nint)
|
|
oii = diag_O1_mat_elem_alpha_beta(mo_integrated_delta_rho_one_point,det_pert,N_int)
|
|
|
|
|
|
do i =1,N_st
|
|
if(CI_electronic_energy(i)>h.and.CI_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(CI_electronic_energy(i) - h) > 1.d-6) then
|
|
c_pert(i) = i_H_psi_array(i) / (CI_electronic_energy(i) - h)
|
|
e_2_pert(i) = c_pert(i) * (i_O1_psi_array(i)+i_O1_psi_array(i) ) + c_pert(i) * c_pert(i) * oii
|
|
H_pert_diag(i) = c_pert(i) * (i_O1_psi_array(i)+i_O1_psi_array(i) )
|
|
else
|
|
c_pert(i) = -1.d0
|
|
e_2_pert(i) = -dabs(i_H_psi_array(i))
|
|
H_pert_diag(i) = c_pert(i) * i_O1_psi_array(i)
|
|
endif
|
|
enddo
|
|
|
|
|
|
end
|
|
|