  The reasons for the anomalously high thermal stability of cubane C8H8 and the
mechanisms of its decomposition are studied by numerically simulating the
dynamics of this metastable cluster at T = 1050 - 2000 K using a tight-binding
potential. The decomposition activation energy is found from the temperature
dependence of the cubane lifetime obtained from the numerical experiment; this
energy is fairly high, Ea = 1.8 - 2.0 eV. The decomposition products are, as a
rule, either C6H6 and C2H2 molecules or the isomer C8H8 with a lower energy.
