Energies of the HOMO, LUMO, and energy gaps of the host, guest species and the complexes (i.e., Al₁₂N₁₂@S-belt, Mg₁₂O₁₂@S-belt, and B₁₂P₁₂@S-belt).

Compounds	E HOMO	E LUMO	E gap	NBO|e|
S-belt	−5.85	−1.42	4.43	—
Al12N12	−6.53	−2.48	4.04	—
Al12N12@S-belt	−5.80	−1.96	3.83	−0.307
Mg12O12	−6.84	−1.69	5.14	—
Mg12O12@S-belt	−5.82	−1.62	4.20	0.064
B12P12	−6.84	−3.10	3.74	—
B12P12@S-belt	−5.80	−2.78	3.02	−0.163