code: def _validate_lattice_vectors(self, lattice_vectors):
          
          dataType = np.float64
          if lattice_vectors is None:
                  lattice_vectors = np.identity(self.dimension, dtype=dataType)
          else:
              lattice_vectors = np.asarray(lattice_vectors, dtype=dataType)
  
              if (self.dimension, self.dimension) != np.shape(lattice_vectors):
                  raise ValueError('Dimensionality of lattice_vectors is '
                                   ' of shape {} not {}.'
                                   .format(np.shape(lattice_vectors),
                                           (self.dimension, self.dimension)))
  
              det = np.linalg.det(lattice_vectors)
              if abs(det) == 0.0:
                  raise ValueError('Co-linear vectors: {}'
                                   'have a determinant of 0.0. Does not '
                                   'define a unit cell.'
                                   .format(lattice_vectors))
  
              if det <= 0.0:
                  raise ValueError('Negative Determinant: the determinant '
                                   'of {} is negative, indicating a left-'
                                   'handed system.' .format(det))
          self.lattice_vectors = lattice_vectors
docs: Ensure that the lattice_vectors are reasonable inputs.