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qp2/src/cipsi/stochastic_cipsi.irp.f
2021-12-20 19:12:14 +01:00

144 lines
4.5 KiB
Fortran

subroutine run_stochastic_cipsi
use selection_types
implicit none
BEGIN_DOC
! Selected Full Configuration Interaction with Stochastic selection and PT2.
END_DOC
integer :: i,j,k
double precision, allocatable :: zeros(:)
integer :: to_select
type(pt2_type) :: pt2_data, pt2_data_err
logical, external :: qp_stop
double precision :: rss
double precision, external :: memory_of_double
PROVIDE H_apply_buffer_allocated distributed_davidson mo_two_e_integrals_in_map
N_iter = 1
threshold_generators = 1.d0
SOFT_TOUCH threshold_generators
rss = memory_of_double(N_states)*4.d0
call check_mem(rss,irp_here)
allocate (zeros(N_states))
call pt2_alloc(pt2_data, N_states)
call pt2_alloc(pt2_data_err, N_states)
double precision :: hf_energy_ref
logical :: has
double precision :: relative_error
relative_error=PT2_relative_error
zeros = 0.d0
pt2_data % pt2 = -huge(1.e0)
pt2_data % rpt2 = -huge(1.e0)
pt2_data % overlap= 0.d0
pt2_data % variance = huge(1.e0)
if (s2_eig) then
call make_s2_eigenfunction
endif
call diagonalize_CI
call save_wavefunction
call ezfio_has_hartree_fock_energy(has)
if (has) then
call ezfio_get_hartree_fock_energy(hf_energy_ref)
else
hf_energy_ref = ref_bitmask_energy
endif
if (N_det > N_det_max) then
psi_det = psi_det_sorted
psi_coef = psi_coef_sorted
N_det = N_det_max
soft_touch N_det psi_det psi_coef
if (s2_eig) then
call make_s2_eigenfunction
endif
call diagonalize_CI
call save_wavefunction
endif
double precision :: correlation_energy_ratio
correlation_energy_ratio = 0.d0
do while ( &
(N_det < N_det_max) .and. &
(sum(abs(pt2_data % pt2(1:N_states)) * state_average_weight(1:N_states)) > pt2_max) .and. &
(sum(abs(pt2_data % variance(1:N_states)) * state_average_weight(1:N_states)) > variance_max) .and. &
(correlation_energy_ratio <= correlation_energy_ratio_max) &
)
write(*,'(A)') '--------------------------------------------------------------------------------'
to_select = int(sqrt(dble(N_states))*dble(N_det)*selection_factor)
to_select = max(N_states_diag, to_select)
call pt2_dealloc(pt2_data)
call pt2_dealloc(pt2_data_err)
call pt2_alloc(pt2_data, N_states)
call pt2_alloc(pt2_data_err, N_states)
call ZMQ_pt2(psi_energy_with_nucl_rep,pt2_data,pt2_data_err,relative_error,to_select) ! Stochastic PT2 and selection
correlation_energy_ratio = (psi_energy_with_nucl_rep(1) - hf_energy_ref) / &
(psi_energy_with_nucl_rep(1) + pt2_data % rpt2(1) - hf_energy_ref)
correlation_energy_ratio = min(1.d0,correlation_energy_ratio)
call write_double(6,correlation_energy_ratio, 'Correlation ratio')
call print_summary(psi_energy_with_nucl_rep, &
pt2_data, pt2_data_err, N_det,N_configuration,N_states,psi_s2)
call save_energy(psi_energy_with_nucl_rep, pt2_data % pt2)
call save_iterations(psi_energy_with_nucl_rep(1:N_states),pt2_data % rpt2,N_det)
call print_extrapolated_energy()
N_iter += 1
if (qp_stop()) exit
! Add selected determinants
call copy_H_apply_buffer_to_wf()
if (save_wf_after_selection) then
call save_wavefunction
endif
PROVIDE psi_coef
PROVIDE psi_det
PROVIDE psi_det_sorted
call diagonalize_CI
call save_wavefunction
call save_energy(psi_energy_with_nucl_rep, zeros)
if (qp_stop()) exit
enddo
if (.not.qp_stop()) then
if (N_det < N_det_max) then
call diagonalize_CI
call save_wavefunction
call save_energy(psi_energy_with_nucl_rep, zeros)
endif
call pt2_dealloc(pt2_data)
call pt2_dealloc(pt2_data_err)
call pt2_alloc(pt2_data, N_states)
call pt2_alloc(pt2_data_err, N_states)
call ZMQ_pt2(psi_energy_with_nucl_rep, pt2_data, pt2_data_err, relative_error, 0) ! Stochastic PT2
call save_energy(psi_energy_with_nucl_rep, pt2_data % pt2)
call print_summary(psi_energy_with_nucl_rep, &
pt2_data , pt2_data_err, N_det, N_configuration, N_states, psi_s2)
call save_iterations(psi_energy_with_nucl_rep(1:N_states),pt2_data % rpt2,N_det)
call print_extrapolated_energy()
endif
call pt2_dealloc(pt2_data)
call pt2_dealloc(pt2_data_err)
end