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quantum_package/plugins/Full_CI/var_pt2_ratio.irp.f

72 lines
2.1 KiB
Fortran

program var_pt2_ratio_run
implicit none
integer :: i,k
double precision, allocatable :: pt2(:), norm_pert(:), H_pert_diag(:)
integer :: N_st, degree
N_st = N_states
allocate (pt2(N_st), norm_pert(N_st),H_pert_diag(N_st))
character*(64) :: perturbation
double precision, allocatable :: psi_det_save(:,:,:), psi_coef_save(:,:)
double precision :: E_fci, E_var, ratio, E_ref, selection_criterion_save
integer :: Nmin, Nmax
pt2 = 1.d0
diag_algorithm = "Lapack"
ratio = 0.d0
Nmin=1
do while (ratio < var_pt2_ratio)
call H_apply_FCI(pt2, norm_pert, H_pert_diag, N_st)
psi_det = psi_det_sorted
psi_coef = psi_coef_sorted
soft_touch N_det psi_det psi_coef
call diagonalize_CI
ratio = (CI_energy(1) - HF_energy) / (CI_energy(1)+pt2(1) - HF_energy)
enddo
threshold_selectors = 1.d0
threshold_generators = 0.999d0
selection_criterion_save = selection_criterion
call diagonalize_CI
call H_apply_FCI_PT2(pt2, norm_pert, H_pert_diag, N_st)
E_ref = CI_energy(1) + pt2(1)
threshold_selectors = 0.999d0
threshold_generators = 0.99d0
Nmax=N_det
Nmin=1
do while (Nmax-Nmin > 1)
ratio = (CI_energy(1) - HF_energy) / (E_ref - HF_energy)
if (ratio < var_pt2_ratio) then
Nmin = N_det
Nmax = max(Nmax,Nmin+10)
! Select new determinants
call H_apply_FCI(pt2, norm_pert, H_pert_diag, N_st)
selection_criterion = selection_criterion_save
SOFT_TOUCH selection_criterion selection_criterion_min selection_criterion_factor
else
Nmax = N_det
N_det = Nmin + (Nmax-Nmin)/2
endif
psi_det = psi_det_sorted
psi_coef = psi_coef_sorted
soft_touch N_det psi_det psi_coef
call diagonalize_CI
call save_wavefunction
print *, 'Det min, Det max: ', Nmin, Nmax
print *, 'Ratio : ', ratio, ' ~ ', var_pt2_ratio
print *, 'HF_energy = ', HF_energy
print *, 'Est FCI = ', E_ref
print *, 'N_det = ', N_det
print *, 'E = ', CI_energy(1)
call ezfio_set_full_ci_energy(CI_energy)
enddo
deallocate(pt2,norm_pert)
end