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mirror of https://github.com/QuantumPackage/qp2.git synced 2024-07-19 17:23:25 +02:00
qp2/src/fci/pt2.irp.f
2021-01-12 14:23:33 +01:00

67 lines
1.9 KiB
Fortran

! -*- mode: f90 -*-
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
! :option:`determinants n_states` wave functions stored in the |EZFIO|
! directory.
!
! The main option for the |PT2| correction is the
! :option:`perturbation pt2_relative_error` which is the relative
! stochastic error on the |PT2| to reach before stopping the
! sampling.
!
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 program pt2
subroutine run
implicit none
use selection_types
integer :: i,j,k
logical, external :: detEq
type(pt2_type) :: pt2_data, pt2_data_err
integer :: degree
integer :: n_det_before, to_select
double precision :: threshold_davidson_in
double precision :: relative_error
double precision, allocatable :: E_CI_before(:)
allocate ( E_CI_before(N_states))
call pt2_alloc(pt2_data, N_states)
call pt2_alloc(pt2_data_err, N_states)
E_CI_before(:) = psi_energy(:) + nuclear_repulsion
relative_error=PT2_relative_error
if (do_pt2) then
call ZMQ_pt2(psi_energy_with_nucl_rep, pt2_data, pt2_data_err, relative_error, 0) ! Stochastic PT2
else
call ZMQ_selection(0, pt2_data)
endif
call print_summary(psi_energy_with_nucl_rep(1:N_states), &
pt2_data, pt2_data_err, N_det,N_configuration,N_states,psi_s2)
call save_energy(E_CI_before, pt2_data % pt2)
call pt2_dealloc(pt2_data)
call pt2_dealloc(pt2_data_err)
deallocate(E_CI_before)
end subroutine run