Calculated Equilibrium Populations of Ti₂C₂@C₈₂ Isomers

High-temperature equilibrium relative populations of two Ti₂C₂@C₈₂ isomers isolated recently are treated by quantum-chemical calculations, viz. endohedrals with the C _s (c);6-C₈₂ and C _3v (b);8-C₈₂ IPR (isolated-pentagon-rule) cages. The calculations are carried out using the Gibbs energy based on the MP2=FU/6-31+G*∼SDD energetics and B3LYP/6-31G*∼SDD entropy. The observed ratio Ti₂C₂@C _s (c);6-C₈₂ : Ti₂C₂@C _3v (b);8-C₈₂=1.6:1 is in the computations obtained at a temperature of 1543 K, i.e., in the supposed synthetic temperature region. Before that point, the two isomers reach their equimolarity at a temperature of 983 K. This fine theory-experiment agreement represents another example of a good performance of the Gibbs-energy based quantum-chemical evaluations of the fullerenic equilibrium compositions under the high-temperature synthetic conditions.