code: def test_mat_exp_orb_params():
      from deepchem.utils.dft_utils import MatExpOrbParams
  
      params = torch.randn(3, 3)
      coeffs = torch.randn(4, 3)
      orb = MatExpOrbParams.params2orb(params, coeffs)[0]
      params2, coeffs2 = MatExpOrbParams.orb2params(orb)
      assert coeffs2.shape == orb.shape
  
file_path: deepchem/deepchem/utils/test/test_dft_utils.py
imports: import pytest
  import numpy
  from typing import Union
label_desc: Use image node_id 3 for calling a global function with example usage: test_mat_exp_orb_params() without return types