The Structures And Stabilities Of Binary Carbon Alloys Clusters

The Clusters, made up of several, dozens and thousands of atoms, molecules or ions combined through physical or chemical bonding force, is a relative-stable non-rigid agglomerate. Its size ranges from several to hundreds of angstroms, belonging to a new generation of matter structure falling in between micro atom, molecule and macro aggregated materials. Its microstructure characteristics and special physical, chemical characteristic open up a new way to find new particularity. In this paper, Geometric structures, energy, and frequency of Mn-C clusters, Si-C clusters and S-C clusters are obtained by using the generalized gradient approximation(GGA) density functional theory(DFT), and the structures with the lowest energy and positive frequency are called as ground states. The charge transfer direction and the dislocation of magnetic moments are determined by analyzing Mulliken atomic charge and atomic magnetic moments. The main contents are presented as the followings:The structures and electronic properties of MnCN(N=1-10) clusters and Mn2CN(N=1-9) clusters are studied systematically by using DFT based on GGA. According to the calculation of frequency and energy, the structures of MnCN(N=1-10) clusters with the lowest energy are obtained. Further calculation are performed on the symmetry, binding energy, the highest occupied molecular orbital state(HOMO), as well as total spin moment, the relationship between binding energy per atom, the second difference of cluster energy and the size of clusters are also discussed in the paper. MnCN(N=1-10) clusters are more stable with the number of C atoms of 5,7,9 which can thus be considered as magic clusters. The charge tends to transfer from Mn atoms to C atoms and the magnetic moment lies primarily on the Mn atom. The configuration of Si-C clusters and S-C clusters in their ground states are calculated with the same theory method mentioned above. The charge tends to transfer from Si atoms to C atoms in SiCN(N=1-8)clusters and SiC3, SiC5 and SiC7 have magnetic moments which lie primarily in Si atoms according to the analysis of atomic charge and magnetic moments of Si atoms and C atoms in SiCN(N=1-8) clusters. The charge also tends to transfer from Si atoms to C atoms for Si2CN(N=1-6) clusters and Si2C2 and Si2C4 cluster have magnetic moments which lies primarily in Si atoms. In terms of the analysis of Mulliken atomic charges and magnetic moments, the charge tends to transfer from S atoms to C atoms, SC2, SC4 and SC6 clusters have magnetic moments which lie evenly in S and C atoms. The charge tends to transfer from C atoms to S atoms for S2CN(N=1-6) clusters and S2C4 cluster has the magnetic moments which lie evenly in S and C atoms.