MgxNiy（x＋y≤5）合金团簇的几何结构和电子性质的理论研究

用密度泛函理论（Density Functional Theory，DFT）的杂化密度泛函B3LYP方法在6311＋g基组水平上对MgxNiy（x＋y≤5）团簇各种可能的构型进行几何结构优化，预测了各团簇的基态结构，并对其电子结构和能量特性等性质进行了理论研究．结果表明：Mg，Ni原子的掺杂使主团簇的基态结构和对称性发生了明显改变，而且Ni原子成键数越多的团簇结构越稳定；在Mg和Ni相互作用形成合金团簇的过程中，发生原子间的电荷转移，使得合金团簇中大多数Mg原子带正电荷M原子带负电荷，而且Ni原子的电荷调节能力较强，容易与其它体系相互作用而形成新的合金材料；从能隙和自然键轨道（Natural Bonding Orbits，NBO）分析显示，MgNi2团簇较稳定，Mg2Ni3团簇具有很好的化学活性．

Study on geometial structures and electronic properties of MgxNiy(x+y≤5) alloys clusters

Possible geometrical structures of MgxNiy（x＋y≤5） clusters were optimized at the 6 - 311 ＋ g level by using the hybrid density functional theory （ B3 LYP）. For the ground state structures of MgxNiy（x＋y≤5） clusters, electronic structure and energy characteristics of MgxNiy（x＋y≤5） clusters were studied. The calculated results show that the ground state structure and symmetry of the alloy clusters vary obviously because of the adulteration of the Mg and Ni atoms, and the cluster becomes more stable with the increasing of the bonds of Ni atom formed. In the process of forming alloy clusters, the charge transfer happens owing to the interaction of the Mg and Ni. Most Mg atom is positive, whereas most of the Ni atom is negative. Moreover, it is very easy to form new alloy material with other systems because of the very strong ability of the Ni atom on charge regulation. Analysis of energy gap and natural bonding orbits（NBO） indicates the MgNi2cluster is comparatively stable, and the chemical activity of the Mg2Ni3 cluster is much strong.