init_lorentz_conserve Subroutine

  subroutine init_lorentz_conserve
    use gs2_layouts, only: g_lo, ie_idx, is_idx, ik_idx, il_idx, it_idx
    use species, only: nspec, spec, is_electron_species
    use kt_grids, only: kperp2, naky, ntheta0
    use theta_grid, only: ntgrid, bmag
    use le_grids, only: energy => energy_maxw, speed => speed_maxw, al, &
         integrate_moment, negrid, forbid
    use gs2_time, only: code_dt, tunits
    use dist_fn_arrays, only: aj0, aj1, vpa
    use le_grids, only: g2le
    use gs2_layouts, only: le_lo
    use redistribute, only: gather, scatter
    use array_utils, only: zero_array
    implicit none
    complex, dimension (1,1,1) :: dum1, dum2
    real, dimension (:,:,:), allocatable :: gtmp
    real, dimension (:,:,:,:), allocatable :: duinv, dtmp, vns
    integer :: ie, il, ik, is, isgn, iglo,  it, ig
    complex, dimension (:,:,:), allocatable :: ctmp, z_big
    complex, dimension(:,:,:), allocatable :: s0tmp, w0tmp, z0tmp
    logical, parameter :: all_procs = .true.

    if(use_le_layout) then
       allocate (ctmp(nxi_lim, negrid+1, le_lo%llim_proc:le_lo%ulim_alloc))
       ! We need to initialise ctmp as it is used as receiving buffer in
       ! g2le redistribute, which doesn't populate all elements
       call zero_array(ctmp)
    end if

    dum1 = 0. ; dum2 = 0.
    allocate(s0tmp(-ntgrid:ntgrid,2,g_lo%llim_proc:g_lo%ulim_alloc))
    allocate(w0tmp(-ntgrid:ntgrid,2,g_lo%llim_proc:g_lo%ulim_alloc))
    allocate(z0tmp(-ntgrid:ntgrid,2,g_lo%llim_proc:g_lo%ulim_alloc))

    allocate (gtmp(-ntgrid:ntgrid,2,g_lo%llim_proc:g_lo%ulim_alloc))
    allocate (duinv(-ntgrid:ntgrid, ntheta0, naky, nspec))
    allocate (dtmp(-ntgrid:ntgrid, ntheta0, naky, nspec))
    allocate (vns(naky,negrid,nspec,3))

    call zero_array(duinv)
    call zero_array(dtmp)

    vns(:,:,:,1) = vnmult(1)*vnew_D
    vns(:,:,:,2) = vnmult(1)*vnew_s
    vns(:,:,:,3) = 0.0

    if (drag) then
       do is = 1, nspec
          if (.not. is_electron_species(spec(is))) cycle
          do ik = 1, naky
             vns(ik,:,is,3) = vnmult(1)*spec(is)%vnewk*tunits(ik)/energy**1.5
          end do
       end do

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! Now get z0 (first form)
       !$OMP PARALLEL DO DEFAULT(none) &
       !$OMP PRIVATE(iglo, ik, ie, il, is, isgn) &
       !$OMP SHARED(g_lo, conservative, z0tmp, code_dt, vns, vpdiff, speed, aj0, vpa) &
       !$OMP SCHEDULE(static)
       do iglo = g_lo%llim_proc, g_lo%ulim_proc
          ik = ik_idx(g_lo,iglo)
          ie = ie_idx(g_lo,iglo)
          il = il_idx(g_lo,iglo)
          is = is_idx(g_lo,iglo)
          do isgn = 1, 2
             ! u0 = -2 nu_D^{ei} vpa J0 dt f0
             if (conservative) then
                z0tmp(:,isgn,iglo) = -2.0*code_dt*vns(ik,ie,is,3)*vpdiff(:,isgn,il) &
                     * speed(ie)*aj0(:,iglo)
             else
                z0tmp(:,isgn,iglo) = -2.0*code_dt*vns(ik,ie,is,3)*vpa(:,isgn,iglo)*aj0(:,iglo)
             end if
          end do
       end do
       !$OMP END PARALLEL DO

       call zero_out_passing_hybrid_electrons(z0tmp)

       if(use_le_layout) then
          call gather (g2le, z0tmp, ctmp)
          call solfp_lorentz (ctmp)
          call scatter (g2le, ctmp, z0tmp)   ! z0 is redefined below
       else
          call solfp_lorentz (z0tmp,dum1,dum2)   ! z0 is redefined below
       end if

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! Now get v0z0

       !$OMP PARALLEL DO DEFAULT(none) &
       !$OMP PRIVATE(iglo, isgn) &
       !$OMP SHARED(g_lo, vpa, gtmp, aj0, z0tmp) &
       !$OMP COLLAPSE(2) &
       !$OMP SCHEDULE(static)
       do iglo = g_lo%llim_proc, g_lo%ulim_proc
          do isgn = 1, 2
             ! v0 = vpa J0 f0
             gtmp(:,isgn,iglo) = vpa(:,isgn,iglo) * aj0(:,iglo) * real(z0tmp(:,isgn,iglo))
          end do
       end do
       !$OMP END PARALLEL DO

       call integrate_moment (gtmp, dtmp, all_procs) ! v0z0

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! Redefine z0 = z0 / (1 + v0z0)

       !$OMP PARALLEL DO DEFAULT(none) &
       !$OMP PRIVATE(iglo, ik, it, is, isgn) &
       !$OMP SHARED(g_lo, z0tmp, dtmp) &
       !$OMP SCHEDULE(static)
       do iglo = g_lo%llim_proc, g_lo%ulim_proc
          it = it_idx(g_lo,iglo)
          ik = ik_idx(g_lo,iglo)
          is = is_idx(g_lo,iglo)
          do isgn = 1, 2
             z0tmp(:,isgn,iglo) = z0tmp(:,isgn,iglo) / (1.0 + dtmp(:,it,ik,is))
          end do
       end do
       !$OMP END PARALLEL DO

    else
       !If drag is false vns(...,3) is zero and hence z0tmp is zero here.
       call zero_array(z0tmp)
    end if

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

    ! du == int (E nu_s f_0);  du = du(z, kx, ky, s)
    ! duinv = 1/du
    if (conservative) then
       !$OMP PARALLEL DO DEFAULT(none) &
       !$OMP PRIVATE(iglo, ik, ie, il, is, isgn) &
       !$OMP SHARED(g_lo, gtmp, vns, vpa, vpdiff, speed) &
       !$OMP SCHEDULE(static)
       do iglo = g_lo%llim_proc, g_lo%ulim_proc
          ik = ik_idx(g_lo,iglo)
          ie = ie_idx(g_lo,iglo)
          il = il_idx(g_lo,iglo)
          is = is_idx(g_lo,iglo)
          do isgn = 1, 2
             gtmp(:,isgn,iglo)  = vns(ik,ie,is,1)*vpa(:,isgn,iglo) &
                  * vpdiff(:,isgn,il)*speed(ie)
          end do
       end do
       !$OMP END PARALLEL DO
    else
       !$OMP PARALLEL DO DEFAULT(none) &
       !$OMP PRIVATE(iglo, ik, ie, is, isgn) &
       !$OMP SHARED(g_lo, gtmp, vpa, vns) &
       !$OMP SCHEDULE(static)
       do iglo = g_lo%llim_proc, g_lo%ulim_proc
          ik = ik_idx(g_lo,iglo)
          ie = ie_idx(g_lo,iglo)
          is = is_idx(g_lo,iglo)
          do isgn = 1, 2
             gtmp(:,isgn,iglo)  = vns(ik,ie,is,1)*vpa(:,isgn,iglo)**2
          end do
       end do
       !$OMP END PARALLEL DO
    end if

    call integrate_moment (gtmp, duinv, all_procs)  ! not 1/du yet

    ! Could replace this with OpenMP using an explicit loop. TAG
    where (abs(duinv) > epsilon(0.0))  ! necessary b/c some species may have vnewk=0
       !duinv=0 iff vnew=0 so ok to keep duinv=0.
       duinv = 1./duinv  ! now it is 1/du
    end where

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! Now get s0 (first form)
    !$OMP PARALLEL DO DEFAULT(none) &
    !$OMP PRIVATE(iglo, ik, it, ie, il, is, isgn, ig) &
    !$OMP SHARED(g_lo, conservative, s0tmp, vns, vpdiff, speed, aj0, code_dt, duinv, vpa) &
    !$OMP SCHEDULE(static)
    do iglo = g_lo%llim_proc, g_lo%ulim_proc
       it = it_idx(g_lo,iglo)
       ik = ik_idx(g_lo,iglo)
       ie = ie_idx(g_lo,iglo)
       il = il_idx(g_lo,iglo)
       is = is_idx(g_lo,iglo)
       do isgn = 1, 2
          ! u1 = -3 nu_s vpa dt J0 f_0 / du
          if (conservative) then
             s0tmp(:,isgn,iglo) = -vns(ik,ie,is,1)*vpdiff(:,isgn,il)*speed(ie) &
                  * aj0(:,iglo)*code_dt*duinv(:,it,ik,is)
          else
             s0tmp(:,isgn,iglo) = -vns(ik,ie,is,1)*vpa(:,isgn,iglo) &
                  * aj0(:,iglo)*code_dt*duinv(:,it,ik,is)
          end if
       end do
    end do
    !$OMP END PARALLEL DO

    call zero_out_passing_hybrid_electrons(s0tmp)

    if(use_le_layout) then
       call gather (g2le, s0tmp, ctmp)
       call solfp_lorentz (ctmp)
       call scatter (g2le, ctmp, s0tmp)   ! s0
    else
       call solfp_lorentz (s0tmp,dum1,dum2)   ! s0
    end if

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! Now get v0s0

    !$OMP PARALLEL DO DEFAULT(none) &
    !$OMP PRIVATE(iglo, isgn) &
    !$OMP SHARED(g_lo, gtmp, vpa, aj0, s0tmp) &
    !$OMP COLLAPSE(2) &
    !$OMP SCHEDULE(static)
    do iglo = g_lo%llim_proc, g_lo%ulim_proc
       do isgn = 1, 2
          ! v0 = vpa J0 f0
          gtmp(:,isgn,iglo) = vpa(:,isgn,iglo) * aj0(:,iglo) * real(s0tmp(:,isgn,iglo))
       end do
    end do
    !OMP END PARALLEL DO

    call integrate_moment (gtmp, dtmp, all_procs)    ! v0s0

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! Redefine s0 = s0 - v0s0 * z0 / (1 + v0z0)

    !$OMP PARALLEL DO DEFAULT(none) &
    !$OMP PRIVATE(iglo, ik, it, is, isgn) &
    !$OMP SHARED(g_lo, s0tmp, dtmp, z0tmp) &
    !$OMP SCHEDULE(static)
    do iglo = g_lo%llim_proc, g_lo%ulim_proc
       ik = ik_idx(g_lo,iglo)
       it = it_idx(g_lo,iglo)
       is = is_idx(g_lo,iglo)
       do isgn=1,2
          s0tmp(:,isgn,iglo) = s0tmp(:,isgn,iglo) - dtmp(:,it,ik,is) * z0tmp(:,isgn,iglo)
       end do
    end do
    !$OMP END PARALLEL DO

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! Now get v1s0

    !$OMP PARALLEL DO DEFAULT(none) &
    !$OMP PRIVATE(iglo, ik, ie, il, is, isgn) &
    !$OMP SHARED(g_lo, conservative, gtmp, vns, speed, vpdiff, aj0, s0tmp, vpa) &
    !$OMP SCHEDULE(static)
    do iglo = g_lo%llim_proc, g_lo%ulim_proc
       ik = ik_idx(g_lo,iglo)
       ie = ie_idx(g_lo,iglo)
       il = il_idx(g_lo,iglo)
       is = is_idx(g_lo,iglo)
       do isgn = 1, 2
          ! v1 = nu_D vpa J0
          if (conservative) then
             gtmp(:,isgn,iglo) = vns(ik,ie,is,1)*speed(ie)*vpdiff(:,isgn,il) &
                  * aj0(:,iglo) * real(s0tmp(:,isgn,iglo))
          else
             gtmp(:,isgn,iglo) = vns(ik,ie,is,1)*vpa(:,isgn,iglo)*aj0(:,iglo) &
                  * real(s0tmp(:,isgn,iglo))
          end if
       end do
    end do
    !$OMP END PARALLEL DO

    call integrate_moment (gtmp, dtmp, all_procs)    ! v1s0

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! Redefine s0 = s0 / (1 + v0s0)

    !$OMP PARALLEL DO DEFAULT(none) &
    !$OMP PRIVATE(iglo, ik, it, is, isgn) &
    !$OMP SHARED(g_lo, s0tmp, dtmp) &
    !$OMP SCHEDULE(static)
    do iglo = g_lo%llim_proc, g_lo%ulim_proc
       ik = ik_idx(g_lo,iglo)
       it = it_idx(g_lo,iglo)
       is = is_idx(g_lo,iglo)
       do isgn=1,2
          s0tmp(:,isgn,iglo) = s0tmp(:,isgn,iglo) / (1.0 + dtmp(:,it,ik,is))
       end do
    end do
    !$OMP END PARALLEL DO

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! Now get w0
    !$OMP PARALLEL DO DEFAULT(none) &
    !$OMP PRIVATE(iglo, ik, it, ie, il, is, isgn, ig) &
    !$OMP SHARED(g_lo, ntgrid, forbid, w0tmp, vns, energy, al , aj1, code_dt, &
    !$OMP spec, kperp2, duinv, bmag, conserve_forbid_zero) &
    !$OMP SCHEDULE(static)
    do iglo = g_lo%llim_proc, g_lo%ulim_proc
       it = it_idx(g_lo,iglo)
       ik = ik_idx(g_lo,iglo)
       ie = ie_idx(g_lo,iglo)
       il = il_idx(g_lo,iglo)
       is = is_idx(g_lo,iglo)
       do isgn = 1, 2
          do ig=-ntgrid,ntgrid
             ! u2 = -3 dt J1 vperp vus a f0 / du
             if ( .not. (forbid(ig,il) .and. conserve_forbid_zero) ) then
                ! Note no conservative branch here, is that right?
                ! Note: energy * al * smz^2 * kperp2 / bmag is alpha^2 where
                ! alpha is the argument to the Bessel function, i.e. aj1 = J1(alpha) / alpha
                ! This appears to leave us with alpha * J1(alpha) whilst Barnes' paper
                ! only includes terms with J1(alpha). Note that alpha = vperp kperp smz/B
                ! so alpha * J1(alpha) = (kperp * smz / B) * vperp J1
                w0tmp(ig, isgn, iglo) = -vns(ik, ie, is, 1) * energy(ie) * al(il) &
                     * aj1(ig, iglo) * code_dt * spec(is)%smz**2 * kperp2(ig, it, ik) * &
                     duinv(ig, it, ik, is) / bmag(ig)
             else
                w0tmp(ig,isgn,iglo) = 0.
             endif
          end do
       end do
    end do
    !$OMP END PARALLEL DO

    call zero_out_passing_hybrid_electrons(w0tmp)

    if(use_le_layout) then
       call gather (g2le, w0tmp, ctmp)
       call solfp_lorentz (ctmp)
       call scatter (g2le, ctmp, w0tmp)
    else
       call solfp_lorentz (w0tmp,dum1,dum2)
    end if

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! Now get v0w0

    !$OMP PARALLEL DO DEFAULT(none) &
    !$OMP PRIVATE(iglo, isgn) &
    !$OMP SHARED(g_lo, gtmp, vpa, aj0, w0tmp) &
    !$OMP COLLAPSE(2) &
    !$OMP SCHEDULE(static)
    do iglo = g_lo%llim_proc, g_lo%ulim_proc
       do isgn = 1, 2
          ! v0 = vpa J0 f0
          gtmp(:,isgn,iglo) = vpa(:,isgn,iglo) * aj0(:,iglo) * real(w0tmp(:,isgn,iglo))
       end do
    end do
    !$OMP END PARALLEL DO

    call integrate_moment (gtmp, dtmp, all_procs)    ! v0w0

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! Redefine w0 = w0 - v0w0 * z0 / (1 + v0z0) (this is w1 from MAB notes)

    !$OMP PARALLEL DO DEFAULT(none) &
    !$OMP PRIVATE(iglo, ik, it, is, isgn) &
    !$OMP SHARED(g_lo, w0tmp, z0tmp, dtmp) &
    !$OMP SCHEDULE(static)
    do iglo = g_lo%llim_proc, g_lo%ulim_proc
       ik = ik_idx(g_lo,iglo)
       it = it_idx(g_lo,iglo)
       is = is_idx(g_lo,iglo)
       do isgn=1,2
          w0tmp(:,isgn,iglo) = w0tmp(:,isgn,iglo) - z0tmp(:,isgn,iglo)*dtmp(:,it,ik,is)
       end do
    end do
    !$OMP END PARALLEL DO

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! Get v1w1

    !$OMP PARALLEL DO DEFAULT(none) &
    !$OMP PRIVATE(iglo, ik, ie, il, is, isgn) &
    !$OMP SHARED(g_lo, conservative, gtmp, vns, speed, vpdiff, aj0, w0tmp, vpa) &
    !$OMP SCHEDULE(static)
    do iglo = g_lo%llim_proc, g_lo%ulim_proc
       ik = ik_idx(g_lo,iglo)
       ie = ie_idx(g_lo,iglo)
       il = il_idx(g_lo,iglo)
       is = is_idx(g_lo,iglo)
       do isgn = 1, 2
          ! v1 = nud vpa J0 f0
          if (conservative) then
             gtmp(:,isgn,iglo) = vns(ik,ie,is,1)*speed(ie)*vpdiff(:,isgn,il) &
                  * aj0(:,iglo) * real(w0tmp(:,isgn,iglo))
          else
             gtmp(:,isgn,iglo) = vns(ik,ie,is,1)*vpa(:,isgn,iglo)*aj0(:,iglo) &
                  * real(w0tmp(:,isgn,iglo))
          end if
       end do
    end do
    !$OMP END PARALLEL DO

    call integrate_moment (gtmp, dtmp, all_procs)    ! v1w1

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! Redefine w0 = w1 - v1w1 * s1 / (1 + v1s1) (this is w2 from MAB notes)

    !$OMP PARALLEL DO DEFAULT(none) &
    !$OMP PRIVATE(iglo, ik, it, is, isgn) &
    !$OMP SHARED(g_lo, w0tmp, s0tmp, dtmp) &
    !$OMP SCHEDULE(static)
    do iglo = g_lo%llim_proc, g_lo%ulim_proc
       ik = ik_idx(g_lo,iglo)
       it = it_idx(g_lo,iglo)
       is = is_idx(g_lo,iglo)
       do isgn=1,2
          w0tmp(:,isgn,iglo) = w0tmp(:,isgn,iglo) - s0tmp(:,isgn,iglo)*dtmp(:,it,ik,is)
       end do
    end do
    !$OMP END PARALLEL DO

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! Get v2w2

    !$OMP PARALLEL DO DEFAULT(none) &
    !$OMP PRIVATE(iglo, ik, ie, il, is, isgn) &
    !$OMP SHARED(g_lo, gtmp, vns, energy, al, aj1, w0tmp) &
    !$OMP SCHEDULE(static)
    do iglo = g_lo%llim_proc, g_lo%ulim_proc
       ik = ik_idx(g_lo,iglo)
       ie = ie_idx(g_lo,iglo)
       il = il_idx(g_lo,iglo)
       is = is_idx(g_lo,iglo)
       do isgn = 1, 2
          ! v2 = nud vperp J1 f0
          ! Note : aj1 = J1(alpha) / alpha, where we have
          ! alpha^2 = energy * al * smz^2 * kperp2 / bmag = vperp^2 smz^2 kperp2 / bmag^2
          ! so energy * al * aj1 = (B / [kperp2 * smz^2]) alpha^2 aj1
          ! = (B / [kperp2 * smz^2]) alpha J1 = vperp J1 / (kperp * smz). As w0tmp
          ! appears to have an extra factor of kperp * smz / B this _may_ work out to
          ! (vperp J1 / B) * ... Is there an extra factor of 1 / B here?
          gtmp(:, isgn, iglo) = vns(ik, ie, is, 1) * energy(ie) * al(il) * aj1(:, iglo) &
               * real(w0tmp(:, isgn, iglo))
       end do
    end do
    !$OMP END PARALLEL DO

    call integrate_moment (gtmp, dtmp, all_procs)   ! v2w2

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
! Redefine w0 = w2 / (1 + v2w2)

    !$OMP PARALLEL DO DEFAULT(none) &
    !$OMP PRIVATE(iglo, ik, it, is, isgn, ig) &
    !$OMP SHARED(g_lo, w0tmp, dtmp) &
    !$OMP SCHEDULE(static)
    do iglo = g_lo%llim_proc, g_lo%ulim_proc
       ik = ik_idx(g_lo,iglo)
       it = it_idx(g_lo,iglo)
       is = is_idx(g_lo,iglo)
       do isgn=1,2
          w0tmp(:,isgn,iglo) = w0tmp(:,isgn,iglo) / (1.0 + dtmp(:,it,ik,is))
       end do
    end do
    !$OMP END PARALLEL DO

    deallocate (gtmp, duinv, dtmp, vns)

    if(use_le_layout) then
       allocate (z_big(-ntgrid:ntgrid, 2, g_lo%llim_proc:g_lo%ulim_alloc))

       ! first set s0le, w0le & z0le
       z_big = cmplx(real(s0tmp), real(w0tmp))

       ! get rid of z0, s0, w0 now that we've converted to z0le, s0le, w0le
       if (allocated(s0tmp)) deallocate(s0tmp)
       if (allocated(w0tmp)) deallocate(w0tmp)

       call gather (g2le, z_big, ctmp)

       if (.not. allocated(s0le)) then
          allocate (s0le(nxi_lim, negrid+1, le_lo%llim_proc:le_lo%ulim_alloc))
          allocate (w0le(nxi_lim, negrid+1, le_lo%llim_proc:le_lo%ulim_alloc))
       end if

       s0le = real(ctmp)
       w0le = aimag(ctmp)

       ! set z0le
       call gather (g2le, z0tmp, ctmp)
       if (allocated(z0tmp)) deallocate(z0tmp)
       if (.not. allocated(z0le)) allocate (z0le(nxi_lim, negrid+1, le_lo%llim_proc:le_lo%ulim_alloc))
       z0le = real(ctmp)

       deallocate (ctmp, z_big)
    else
       !Only need the real components (imaginary part should be zero, just
       !use complex arrays to allow reuse of existing integrate routines etc.)
       if (.not. allocated(s0)) then
          allocate (s0(-ntgrid:ntgrid,2,g_lo%llim_proc:g_lo%ulim_alloc))
          s0=real(s0tmp)
          deallocate(s0tmp)
       endif

       if (.not. allocated(w0)) then
          allocate (w0(-ntgrid:ntgrid,2,g_lo%llim_proc:g_lo%ulim_alloc))
          w0=real(w0tmp)
          deallocate(w0tmp)
       endif

       if (.not. allocated(z0)) then
          allocate (z0(-ntgrid:ntgrid,2,g_lo%llim_proc:g_lo%ulim_alloc))
          z0=real(z0tmp)
          deallocate(z0tmp)
       endif
    end if

  end subroutine init_lorentz_conserve