code: def cart2frac_all(coordinates, lattice_array):
      
      frac_coordinates = deepcopy(coordinates)
      for coord in range(frac_coordinates.shape[0]):
          frac_coordinates[coord] = fractional_from_cartesian(
              frac_coordinates[coord], lattice_array)
      return frac_coordinates
docs: Convert all cartesian coordinates to fractional.