attempt_die_precond Function

    function attempt_die_precond(DetCurr, Kii, realwSign, WalkExcitLevel, DetPos) result(ndie)
        ! Should we kill the particle at determinant DetCurr.
        ! The function allows multiple births (if +ve shift), or deaths from
        ! the same particle. The returned number is the number of deaths if
        ! positive, and the
        !
        ! In:  DetCurr - The determinant to consider
        !      Kii     - The diagonal matrix element of DetCurr (-Ecore)
        !      wSign   - The sign of the determinant being considered. If
        !                |wSign| > 1, attempt to die multiple particles at
        !                once (multiply probability of death by |wSign|)
        !      DetPos  - Position of the spawning determinant
        ! Ret: ndie    - The number of deaths (if +ve), or births (If -ve).

        integer, intent(in) :: DetCurr(nel)
        real(dp), dimension(lenof_sign), intent(in) :: RealwSign
        real(dp), intent(in) :: Kii
        real(dp), dimension(lenof_sign) :: ndie
        integer, intent(in) :: WalkExcitLevel

        integer, intent(in), optional :: DetPos
        character(*), parameter :: t_r = 'attempt_die_normal'

        real(dp) :: probsign, r
        real(dp), dimension(inum_runs) :: fac
        integer :: i, run
#ifdef CMPLX_
        real(dp) :: rat(2)
#else
        real(dp) :: rat(1)
#endif
        unused_var(Kii); unused_var(DetPos);
        unused_var(DetCurr); unused_var(DetPos)


        do i = 1, inum_runs
            fac(i) = tau

            ! And for tau searching purposes
            call log_death_magnitude(1.0_dp)
        end do

        if ((tRealCoeffByExcitLevel .and. (WalkExcitLevel <= RealCoeffExcitThresh)) &
            .or. tAllRealCoeff) then
            do run = 1, inum_runs
                ndie(min_part_type(run)) = fac(run) * abs(realwSign(min_part_type(run)))
#ifdef CMPLX_
                ndie(max_part_type(run)) = fac(run) * abs(realwSign(max_part_type(run)))
#endif
            end do
        else
            do run = 1, inum_runs

                ! Subtract the current value of the shift, and multiply by tau.
                ! If there are multiple particles, scale the probability.

                rat(:) = fac(run) * abs(realwSign(min_part_type(run):max_part_type(run)))

                ndie(min_part_type(run):max_part_type(run)) = real(int(rat), dp)
                rat(:) = rat(:) - ndie(min_part_type(run):max_part_type(run))

                ! Choose to die or not stochastically
                r = genrand_real2_dSFMT()
                if (abs(rat(1)) > r) ndie(min_part_type(run)) = &
                    ndie(min_part_type(run)) + real(nint(sign(1.0_dp, rat(1))), dp)
#ifdef CMPLX_
                r = genrand_real2_dSFMT()
                if (abs(rat(2)) > r) ndie(max_part_type(run)) = &
                    ndie(max_part_type(run)) + real(nint(sign(1.0_dp, rat(2))), dp)
#endif
            end do
        end if
    end function attempt_die_precond