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quantum_package/plugins/CID_selected/cid_selected.irp.f
2016-02-19 00:20:28 +01:00

32 lines
1.0 KiB
Fortran

program cisd
implicit none
integer :: i,k
double precision, allocatable :: pt2(:), norm_pert(:), H_pert_diag(:),E_old(:)
integer :: N_st, iter
character*(64) :: perturbation
N_st = N_states
allocate (pt2(N_st), norm_pert(N_st), H_pert_diag(N_st),E_old(N_st))
pt2 = 1.d0
perturbation = "epstein_nesbet"
E_old(1) = HF_energy
do while (maxval(abs(pt2(1:N_st))) > 1.d-6)
print*,'----'
print*,''
call H_apply_cisd_selection(perturbation,pt2, norm_pert, H_pert_diag, N_st)
call diagonalize_CI
print*,'N_det = ',N_det
do i = 1, N_st
print*,'state ',i
print *, 'PT2 = ', pt2(i)
print *, 'E = ', CI_energy(i)
print *, 'E_before +PT2 = ', (E_old(i)+pt2(i))
! print *, 'E+PT2_new= ', (E_old(1)+1.d0*pt2(1)+H_pert_diag(1))/(1.d0 +norm_pert(1))
enddo
E_old = CI_energy
enddo
deallocate(pt2,norm_pert,H_pert_diag)
end