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熔融Rb2ZnCl4的分子动力学模拟研究
MOLECULAR DYNAMICS STUDY ON THE STRUCTURES OF MOLTEN Rb 2ZnCl 4
【摘要】 采用在RbCl模拟和ZnCl2模拟中选用的两体有效势,进行了晶态和熔融态Rb2ZnCl4的分子动力学模拟.模拟给出了Rb2ZnCl46种径向分布函数,ZnCl和RbCl间径向分布函数与新近的广延X射线吸收精细结构实验结果很好相符.在模拟产生的瞬态构型基础上进行了键序参数分析,研究了晶态和熔融态中的局部结构.模拟结果表明,Zn原子与其近邻Cl原子构成相当稳定的正四面体结构,并且熔融Rb2ZnCl4中Zn/Cl正四面体结构比熔融ZnCl2中更加稳定.大量相当稳定的(ZnCl4)2-的存在又未明显构成网络,是熔融Rb2ZnCl4结构的主要特征.晶态模拟未能反映晶态RbCl间的复杂配位,表明两体有效势对于描述晶态Rb2ZnCl4中Rb原子的行为是不够的
【Abstract】 Abstract The structures of molten and crystalline states of Rb2ZnCl4 have been simulated by molecular dynamics with the effective potentials which had been applied in the simulations of RbCl and ZnCl2 systems.Six radial distribution functions (RDF) simulated are presented,of which Zn Cl and Rb Cl RDFs are in good accordance with the recent EXAFS experimental results.Based on the instantaneous configurations given by the simulations,the local structures in molten and crystalline states have been studied with bond order parameter method.The results show that the Zn atom and its neighboring Cl atoms form a stable tetrahedral structure,and the Zn/Cl tetrahedral structures in molten Rb2ZnCl4 are stabler than those in molten ZnCl2.The presence of a good quantity of stable (ZnCl4) 2- units without apparent network like structures is the typical characteristics of the molten Rb2ZnCl4.The simulations for crystalline state did not describe the complex coordinations between Rb and Cl atoms in detail,which showed that the two body effective potentials are not enough to simulate the behaviors of Rb atoms in the crystalline Rb 2ZnCl 4.
- 【文献出处】 物理学报 ,Acta Physica Sinica , 编辑部邮箱 ,1998年02期
- 【分类号】O561
- 【被引频次】6
- 【下载频次】71