docs: def get_best_fit_rot_mat(from_coord, to_coord):
      """
      Compute best-fit rotation matrix.
  
      The best-fit rotation matrix rotates from_coord such that the RMSD
      between the 2 sets of coordinates are minimized after the rotation.
  
      Parameters
      ----------
      from_coord, to_coord : np.array
          Nx3 coordinate arrays, where N is the number of atoms. The
          from_coord will rotated such that the rotation will minimize
          the RMSD between the rotated from_coord and to_coord.
  
      Returns
      -------
      np.array
          3x3 rotation matrix
      """
      superimpose_inst.set(to_coord.astype('float64'),
                           from_coord.astype('float64'))
      superimpose_inst.run()
  
      return superimpose_inst.get_rotran()[0].T