3D visualization of logarithmically spaced density isosurfaces in the inner-most region of the computational domain showing the structure of the second Larson core, in the case of ideal (top) and non-ideal (bottom) MHD. The isosurfaces have been cut half-way in the x-direction. The magnetic field lines are overlayed and have been coloured according to the magnitude of the magnetic field vector. The insets in the lower left corner of each panel show (with the same spatial scale) the central region of the system without the B field for a better view of the morphology. The density and magnetic field colour scales apply to both panels.