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quantum_package/src/fci/pt2.irp.f

52 lines
1.6 KiB
Fortran

program pt2
implicit none
BEGIN_DOC
! Second order perturbative correction to the wave function contained in the EZFIO directory.
!
! This programs runs the stochastic PT2 correction on all "n_states" wave function stored in the EZFIO folder (see :option:`determinant n_states`).
!
! The option for the PT2 correction are the "pt2_relative_error" which is the relative stochastic
!
! error on the PT2 to reach before stopping the stochastic sampling. (see :option:`perturbation pt2_relative_error`)
END_DOC
if (.not. is_zmq_slave) then
read_wf = .True.
threshold_generators = 1.d0
SOFT_TOUCH read_wf threshold_generators
PROVIDE mo_two_e_integrals_in_map
PROVIDE psi_energy
call run
else
call run_slave_cipsi
endif
end
subroutine run
implicit none
integer :: i,j,k
logical, external :: detEq
double precision :: pt2(N_states)
integer :: degree
integer :: n_det_before, to_select
double precision :: threshold_davidson_in
double precision :: E_CI_before(N_states), relative_error, error(N_states), variance(N_states), norm(N_states), rpt2(N_states)
pt2(:) = 0.d0
E_CI_before(:) = psi_energy(:) + nuclear_repulsion
relative_error=PT2_relative_error
call ZMQ_pt2(psi_energy_with_nucl_rep,pt2,relative_error,error, variance, &
norm,0) ! Stochastic PT2
do k=1,N_states
rpt2(:) = pt2(:)/(1.d0 + norm(k))
enddo
call print_summary(psi_energy_with_nucl_rep(1:N_states),pt2,error,variance,norm,N_det,N_occ_pattern,psi_s2)
call save_energy(E_CI_before,pt2)
end