init_collisions Subroutine

  subroutine init_collisions(collisions_config_in)
    use species, only: init_species, nspec, spec
    use theta_grid, only: init_theta_grid, ntgrid
    use kt_grids, only: init_kt_grids, naky, ntheta0
    use le_grids, only: init_le_grids, nlambda, negrid
    use run_parameters, only: init_run_parameters
    use gs2_layouts, only: init_dist_fn_layouts, init_gs2_layouts
    use mp, only: nproc, iproc
    implicit none
    type(collisions_config_type), intent(in), optional :: collisions_config_in
    if (initialized) return
    initialized = .true.
    call init_gs2_layouts
    call init_species

    hyper_colls = .false.
    if (any(spec%nu_h > epsilon(0.0))) hyper_colls = .true.

    call init_theta_grid
    call init_kt_grids
    call init_le_grids
    call init_run_parameters
    call init_dist_fn_layouts (ntgrid, naky, ntheta0, nlambda, negrid, nspec, nproc, iproc)
    call read_parameters(collisions_config_in)

    call init_arrays

  end subroutine init_collisions