def calculate_pore_volume_opt(self, **kwargs):
self.pore_volume_opt = sphere_volume(<EOL>self.calculate_pore_diameter_opt(**kwargs) / <NUM_LIT:2>)<EOL>self.properties['<STR_LIT>'] = self.pore_volume_opt<EOL>return self.pore_volume_opt<EOL>
Return the intrinsic pore volume (for the optimised pore centre).

Similarly to :func:`calculate_pore_volume` this method returns the
the volume intrinsic pore diameter, however, for the
:func:`calculate_pore_diameter_opt` returned value.

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