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quantum_package/plugins/Full_CI/full_ci.irp.f

117 lines
3.8 KiB
Fortran

program full_ci
implicit none
integer :: i,k
print *, '===================================================================='
print *, 'This program is slow. Consider using the Full_CI_ZMQ module instead.'
print *, '===================================================================='
call sleep(2)
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
pt2 = 1.d0
diag_algorithm = "Lapack"
if (N_det > N_det_max) then
call diagonalize_CI
call save_wavefunction
psi_det = psi_det_sorted
psi_coef = psi_coef_sorted
N_det = N_det_max
soft_touch N_det psi_det psi_coef
call diagonalize_CI
call save_wavefunction
print *, 'N_det = ', N_det
print *, 'N_states = ', N_states
print *, 'PT2 = ', pt2
print *, 'E = ', CI_energy
print *, 'E+PT2 = ', CI_energy+pt2
print *, '-----'
endif
double precision :: i_H_psi_array(N_states),diag_H_mat_elem,h,i_O1_psi_array(N_states)
double precision :: E_CI_before(N_states)
if(read_wf)then
call i_H_psi(psi_det(1,1,N_det),psi_det,psi_coef,N_int,N_det,psi_det_size,N_states,i_H_psi_array)
h = diag_H_mat_elem(psi_det(1,1,N_det),N_int)
selection_criterion = dabs(psi_coef(N_det,1) * (i_H_psi_array(1) - h * psi_coef(N_det,1))) * 0.1d0
soft_touch selection_criterion
endif
integer :: n_det_before
print*,'Beginning the selection ...'
E_CI_before(1:N_states) = CI_energy(1:N_states)
do while (N_det < N_det_max.and.maxval(abs(pt2(1:N_st))) > pt2_max)
n_det_before = N_det
call H_apply_FCI(pt2, norm_pert, H_pert_diag, N_st)
PROVIDE psi_coef
PROVIDE psi_det
PROVIDE psi_det_sorted
call diagonalize_CI
if (N_det > N_det_max) then
N_det = N_det_max
psi_det = psi_det_sorted
psi_coef = psi_coef_sorted
touch N_det psi_det psi_coef psi_det_sorted psi_coef_sorted psi_average_norm_contrib_sorted
endif
call save_wavefunction
if(n_det_before == N_det)then
selection_criterion = selection_criterion * 0.5d0
endif
print *, 'N_det = ', N_det
print *, 'N_states = ', N_states
do k = 1, N_states
print*,'State ',k
print *, 'PT2 = ', pt2(k)
print *, 'E = ', CI_energy(k)
print *, 'E(before)+PT2 = ', E_CI_before(k)+pt2(k)
enddo
print *, '-----'
if(N_states.gt.1)then
print*,'Variational Energy difference'
do i = 2, N_states
print*,'Delta E = ',CI_energy(i) - CI_energy(1)
enddo
endif
if(N_states.gt.1)then
print*,'Variational + perturbative Energy difference'
do i = 2, N_states
print*,'Delta E = ',E_CI_before(i)+ pt2(i) - (E_CI_before(1) + pt2(1))
enddo
endif
E_CI_before(1:N_states) = CI_energy(1:N_states)
call ezfio_set_full_ci_energy(CI_energy(1))
enddo
N_det = min(N_det_max,N_det)
touch N_det psi_det psi_coef
call diagonalize_CI
if(do_pt2)then
print*,'Last iteration only to compute the PT2'
threshold_generators = threshold_generators_pt2
threshold_selectors = threshold_selectors_pt2
SOFT_TOUCH threshold_generators threshold_selectors
call H_apply_FCI_PT2(pt2, norm_pert, H_pert_diag, N_st)
print *, 'Final step'
print *, 'N_det = ', N_det
print *, 'N_states = ', N_states
print *, 'PT2 = ', pt2
print *, 'E = ', CI_energy(1:N_states)
print *, 'E+PT2 = ', CI_energy(1:N_states)+pt2(1:N_states)
print *, '-----'
call ezfio_set_full_ci_energy_pt2(CI_energy(1)+pt2(1))
endif
call save_wavefunction
deallocate(pt2,norm_pert)
end