Structural phase transitions in the process of an $A_{60}$ cluster formation

The explanation of the existence of the two critical parameters corresponding to the formation of an $A_{60}$ fullerene cluster in the lattice gas model is given. The presented treatment suggests the possibility of the existence of the two phases of the same symmetry type—high-density phase and low-density phase. These theoretical results can be applied to the carbon fullerene or nanotube research.