code: def lattice_array_to_unit_cell(lattice_array):
      
      cell_lengths = np.sqrt(np.sum(lattice_array**2, axis=0))
      gamma_r = np.arccos(lattice_array[0][1] / cell_lengths[1])
      beta_r = np.arccos(lattice_array[0][2] / cell_lengths[2])
      alpha_r = np.arccos(
          lattice_array[1][2] * np.sin(gamma_r) / cell_lengths[2]
          + np.cos(beta_r) * np.cos(gamma_r)
          )
      cell_angles = [
          np.rad2deg(alpha_r), np.rad2deg(beta_r), np.rad2deg(gamma_r)
          ]
      return np.append(cell_lengths, cell_angles)
docs: Return crystallographic param. from unit cell lattice matrix.