@property<EOL><INDENT>def rhogm(self):<DEDENT>
Vmg = self.Vmg<EOL>if Vmg:<EOL><INDENT>return <NUM_LIT:1.>/Vmg<EOL><DEDENT>return None<EOL>
r'''Molar density of the chemical in the gas phase at the
        current temperature and pressure, in units of [mol/m^3].

        Utilizes the object oriented interface and
        :obj:`thermo.volume.VolumeGas` to perform the actual calculation of
        molar volume.

        Examples
        --------
        >>> Chemical('tungsten hexafluoride').rhogm
        42.01349946063116