def frac_coords(self, frac_coords):
        """
        Fractional a coordinate
        """
        self._frac_coords = np.array(frac_coords)
        self._coords = self._lattice.get_cartesian_coords(self._frac_coords)
def frac_coords ( self , frac_coords ) : self . _frac_coords = np . array ( frac_coords ) self . _coords = self . _lattice . get_cartesian_coords ( self . _frac_coords )
Fractional a coordinate