def calculate_pore_volume(self):
self.pore_volume = sphere_volume(self.calculate_pore_diameter() / <NUM_LIT:2>)<EOL>self.properties['<STR_LIT>'] = self.pore_volume<EOL>return self.pore_volume<EOL>
Return the intrinsic pore volume.

Returns
-------
:class:`float`
    The intrinsic pore volume.