Molecular dynamics simulation of calcium fluoride——Crystalline, superionic, molten and quenched-amor

来源 :Science in China,Ser.B | 被引量 : 0次 | 上传用户:longyouxi
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
The results from the molecular dynamics simulations on crystalline, superionic, molten and quenched-amorphous states of calcium fluoride system are reported. The Ca++ and F- sublattices are studied by using the method of bond order parameters. The result shows that both Ca++ and F- sublattices can be described with the bond-orientation normal distribution model. In the superionic phase the Ca++ cations keep their original stable fcc frame, but in the F- case random distortion generates from their original simple cubic (sc) structure. The simulation on the molten phase gives three radial distribution functions that are difficult to separate from the experimental X-ray diffraction data. The simulation of quenched-amorphous state shows that a dense random packing of equivalent spheres centered by Ca++ cations occurs in the system simulated. However, the system quenched is not stable enough because the Ca++ cation and F- anions around it do not form themselves into a certain configuration. The results from the molecular dynamics simulations on crystalline, superionic, molten and quenched-amorphous states of calcium fluoride system are reported. The Ca ++ and F-sublattices are studied by using the method of bond order parameters. In the superionic phase the Ca ++ cations keep their original stable fcc frame, but in the F-case random distortion generates from their original simple cubic (sc) structure. The simulation on the molten phase gives three radial distribution functions that are difficult to separate from the experimental X-ray diffraction data. The simulation of quenched-amorphous state shows that a dense random packing of equivalent spheres centered by Ca ++ cations occurs in the system simulated. However, the system quenched is not stable enough because the Ca ++ cation and F-anions around it do not form themselves into a certain configuration.
其他文献
Super-silicic garnet which exists stably at more than 5 GPa is a typical ultra-high pressure mineral. The super-silicic garnet and super-titanic garnet were dis
目的:通过高脂诱导营养性肥胖大鼠模型,观察调脂积冲剂对肥胖大鼠体重、Lee’s指数、血清胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白(HDL)、低密度脂蛋白(LDL)、血糖(FBG)、真
鸡西矿业集团公司张辰煤矿西三采区3
期刊
江苏省赣榆县是全国首批沿海对外开放县,沿海有6个乡镇,15万多人,60多公里海岸线,23万亩滩涂,108万亩浅海域。改革开放以后,沿海人捷足先登,向沉睡的滩涂开战,向广阔的大海
在中国“入世”的问题上,如果说过去我们已有过历时13年,从“黑发人谈到白发人”的波折与艰辛,那么,未来我们还将经历观念磨合和体制嬗变的阵痛!作为内陆大都市的武汉,对这种
河南省农科院植保所在花生田蛴螬环保型防治药剂的研制上获得重大突破。该所从事地下害虫防治研究的科技人员经过多年精心研究试验,日前发明了一种高效、低毒、低残留的绿色
白细胞介素-12(Interleukin-12,IL-12)家族成员IL-12、IL-23、IL-27三者及其各自受体在结构上的相似性,使得它们在发挥调节NK细胞活性、T细胞增殖和细胞因子产生以及抗体类别
以茯苓、黄芪提取液中多糖和甲苷的含量及出膏率为指标,优选了提取工艺,并考察了两种精制工艺对复方免疫成分的影响。结果为浸泡细粉药材12h,提取1次,料水比1:15,为最佳提取
介绍了组合顶头的组合方式、使用材料、性能特征及对钢管质量的影响等。 Introduced the combination of head combination, the use of materials, performance characteri
本文采用特制的双毛细管雾化器引入有机溶剂,产生的气溶胶经预混合,在载气(Ar)的作用下导入ICP中激发.比较了有机溶剂在FI-ICP与非FI-ICP体系中的行为,所得实验结果表明:(1)引入微体积的有机溶剂于FI-ICP体系,对