Mass spectrometric and first principles study of AlnC− clusters

We study aluminum–carbon mixed clusters by using time-of-flight mass spectrum experiments and ab initio calculations. Mass abundance distributions are obtained for anionic aluminum and aluminum–carbon mixed clusters. Besides the well-known magic aluminum clusters such as the Al13− and Al23−, the Al7C− cluster is found to be particularly stable among those AlnC− clusters. Density functional calculations are performed to determine the ground state structures of AlnC− clusters. Our results show that the Al7C− is a magic cluster with extremely high stability, which might serve as a building block for cluster-assembled materials.