Shift a molecule to Origin.

        This function takes the molecule's coordinates and adjust them so that
        the centre of mass of the molecule coincides with the origin of the
        coordinate system.

        Returns
        -------
        None : :class:`NoneType`

def shift_to_origin(self, **kwargs):
        """
        Shift a molecule to Origin.

        This function takes the molecule's coordinates and adjust them so that
        the centre of mass of the molecule coincides with the origin of the
        coordinate system.

        Returns
        -------
        None : :class:`NoneType`

        """
        self.coordinates = shift_com(self.elements, self.coordinates, **kwargs)
        self._update()