These are orbital isosurfaces calculated by Quantum Mechanical methods (in
this case spin restricted Hartree-Fock SCF theory). They represent the
actual structure of the orbitals found in the target molecule. The red
surfaces represent the positive component of the orbital. The blue
represent the negative component of the orbital
The first image is the lowest energy unoccupied molecular orbital. The
second image is the highest energy occupied molecular orbital.
They are not povray blob structures.
Jim