原子团簇P_(12)结构的从头算研究

使用分子图形学方法设计出 2 0种 P1 2 模型 ,并对其进行了分子力学、PM3半经验量子化学和 Gaussian98优化 .在 P1 2 模型设计中 ,磷原子采用二、三或四配位成键方式 .为了保证得到全局最小点 ,足够数量的模型设计是必要的 .从模型优化后的能量比较可得知 ,由 2个楔状 P8共享 4个原子的 D3d结构最稳定 .大多数 P1 2 采用全部原子均以全三配位的成键方式 ,而含有二配位结构总能量较高 .大量的 P1 2 结构中含有楔状 P8的子结构 ,许多磷原子团簇由四面体 P4和楔状 P8演变生成的 ,它们是构造大分子磷原子团簇的重要的结构基元 .磷原子团簇中的平面五员环子结构较平面六员环子结构稳定

An ab initio Study on e Phosphorus Clusters P_(12)

Twenty structures of P 12 were acquired with molecular graphics and carried out optimizations with molecular mechanics, PM3 semiempirical and ab initio calculations. The phosphorus atoms could be in twofold, threefold or fourfold coordination in these structures. The imaging of enough cluster models can help to locate the global minimum. The model of D 3d symmetry derived from the merging two cuneane P 8 via the sharing of four atoms is the most stable isomer. Many P 12 structures have all the atoms in threefold mode and those that have atoms(s) in twofold coordination have higher energies. Both tetrahedral P 4 and cuneane P 8 are common components and could be important candidates for the construction of larger clusters. A planar pentagon structure is more popular than a hexagonal one in phosphorus clusters.