Novel supersalts formed by interaction of H ₂ M ₃ superalkalis (M = Li and Na) with AlF ₄ , BeF ₃ and NO ₃ superhalogens

Supersalts are ionic compounds formed by pairing superalkali cations with superhalogen anions, resulting in systems with strong charge-transfer characteristics. This study investigates novel supersalts of the form H 2 M 3 –Y (M = Li or Na; Y = AlF 4 , BeF 3 , NO 3 ) using the MP2/aug-cc-pVTZ level of theory. Their stability was evaluated via binding energy ( E b ) and dissociation energy ( E d ), with H 2 Li 3 –AlF 4 showing the highest binding energy (11.35 eV), followed by H 2 Li 3 -BeF 3 (10.66 eV) and H 2 Li 3 -NO 3 (7.58 eV). Net charge analysis confirms significant charge separation (+0.93 e / −0.92 e in Li systems), supporting the ionic nature of these complexes, further validated by QTAIM analysis. The HOMO–LUMO gap is highest for H 2 Li 3 –BeF 3 (10.33 eV), indicating relatively higher electronic stability. The results indicate that Li-based supersalts are more stable than their Na-based counterparts, with stability following the trend AlF 4 > BeF 3 > NO 3 . These findings provide a basis for understanding charge-transfer-driven molecular systems.