C72 (or C120) cluster growth from C36 (or C60) clusters

We suggest fabricating larger clusters of equal size by dimerizing smaller ones, and performed molecular dynamics simulations with Brenner potential on C72 (or C120) cluster growth from C36 (or C60) clusters in He atmosphere at temperatures between 100 and 4000 K, showing that the resultant clusters may be dumbbell, pod or ball shape, depending on the ambient temperatures. Optimized by the Hartree-Fock method, these final structures keep nearly unchanged. The dimerizing dynamics was found to approximately satisfy the Arrhenius law and the activation energy for C60, 1.860 eV, is close to previous measurement.