Ground States of Silicon-Multisubstituted Fullerene:First-Principles Calculations and Monte Carlo Simulations

We present a systematical study on the possible stable structures of C60-xSix（x = 1-12） fullerenes using firstprinciples calculations combined with Monte-Carlo simulations.The initial fuUerenes randomly substituting with silicon atoms are firstly generated and then their total energies are calculated quickly.The ground-state structures are found by the annealing process where Si atoms exchange their positions with C atoms.The stable structures are finally obtained through first-principles calculations with high precision.For the cases with a small amount of Si atoms（x≤4）,results similar to those report previously are achieved.Some new stable Si-doped fuUerenes with more Si atoms are also predicated.The results show that Si atoms in the C60-xSix（x<4） fuUerenes have a trend of segregation with C atoms.The minimum-energy structure changes from a chemical unstable state to a chemical stable state when x≥8.