“…Here, ZPE is the zero-point energy correction; is the electronic energy; E Rot + E Trans + E Vib are the contributions to energy due to translation, rotation, and vibration as function of temperature, respectively. In order to compute the probability of the occurrence of one particular cluster in an ensemble of Be 4 B 8 clusters (Boltzmann ensemble at thermal equilibrium) as a function of temperature, we employed the probability of occurrence [ 33 , 76 , 80 , 81 , 135 , 136 , 137 , 138 , 139 , 140 ] given in Equation (6): where , is the Boltzmann constant, T is the temperature, and k is the Gibbs free energy of the k th isomer. Any molecular properties observed are statistical averages over a Boltzmann ensemble of clusters.…”