17.分子离子材料的计算机模拟.ppt

1、信息检索与文献阅读 （化学0701-0702）,2010年04月23日,第一部分 化学专业基础英语阅读 （20学时） 第二部分 英文阅读材料 （12学时） 第三部分 信息检索 （16学时）,第一章 作为定量科学和物质科学的化学 第二章 原子、分子和离子 第三章 气态 第四章 热化学 第五章 有机化合物和基团的命名 第六章 无机化学、有机化学、物理化学、分 析化学化学术语,第一部分 化学专业基础英语阅读（20学时）,第二部分 英文阅读材料（12学时）,第一章 松香酸度的标准测试方法 第二章 族半导体制备的新方法：InP纳米晶 的超声化学合成 第三章 专利说明书 第四章 销售合同 第四章 分子离子

2、材料的计算机模拟 第四章 透射Laue法的X射线衍射,第三部分 信息检索（16学时）,第一章 信息检索基础 第二章 超星图书馆 第三章 中国期刊网 第四章 维普 第五章 工程索引（Ei） 第六章 美国化学文摘（CA） 第七章 专利,教材和参考书： 1、魏高原， 化学专业基础英语知识（I）（Introductory Chemistry Speciality English）， 北京大学出版社，2004。 2、 Reading Materials (自编讲义) 。 3、 陈英，科技信息检索（第二版），科学出版社，2005。 4、 万锡仁， Information Retrieval and Rel

3、ated Reading Materials，（待出版）。 5、 美 Philip Ball 著，魏高原等注释， 化学专业基础英语（II）， 北京大学出版社，2001。,课堂教学内容安排,第一节课 教学要求说明 词汇预习 课文阅读理解 第二节课 课文阅读理解（续） 答疑 布置课后作业 词汇和短文翻译（书面练习）,一、教学要求 掌握：期刊综述论文的书写格式；有 关专业词汇和科技英语的表达。 熟悉：有关分子模拟的基本知识。 了解：分子模拟的研究现状。,文献综述是对某一方面的专题收集大量情报资料后经综合分析而写成的一种学术论文， 它是科学文献的一种。 文献综述是反映当前某一领域中某分支学科或重要专题

4、的最新进展、学术见解和建议,它往往能反映出有关问题的新动态、新趋势、新水平、新原理和新技术等.,综述论文简介,“综”是要求对文献资料进行综合分析、归纳整理，使材料更精练明确、更有逻辑层次；“述”就是要求对综合整理后的文献进行比较专门的、全面的、深入的、系统的论述。总之，文献综述是作者对某一方面问题的历史背景、前人工作、争论焦点、研究现状和发展前景等内容进行评论的科学性论文。,Computer modelling of molecular ionic materials 分子离子材料的计算机模拟,二、 词汇（New Words and Expressions）,computer modeling

5、 计算机模拟 molecular ionic material 分子离子材料 abstract 摘要 review 综述，评论 ionic interaction 离子相互作用 covalent interaction 共价相互作用 interatomic force 原子间力,computer modeling molecular ionic material abstract review ionic interaction covalent interaction interatomic force,keyword 关键词 interatomic potential 原子间势函数 int

6、roduction 引言 cation 阳离子 anion阴离子 anionic material 阴离子材料 typify成为.的典型, 代表,keyword interatomic potential introduction cation anion anionic material typify,calcium carbonate碳酸钙 molecular cationic material 分子阳离子材料 ammonium halide卤化铵 ammonium nitrate硝酸铵 cohesion结合, 凝聚 appendix附录 potential parameter势参数,ca

7、lcium carbonate molecular cationic material ammonium halide ammonium nitrate Cohesion appendix potential parameter,interatomic potential model 原子间势函数模型 non-bonded interaction 非键相互作用 bonded interaction 成键相互作用 empirical fitting 经验拟合 charge 电荷 partial charge 分数电荷 formal charge 形式电荷,interatomic potentia

8、l model non-bonded interaction bonded interaction empirical fitting charge partial charge formal charge,bond-stretching 键伸缩 bond-bending 键弯曲 torsional interaction 张力（扭力）作用 equilibrium bond length 平衡键长 bond angle 键角 force constant力常数,bond-stretching bond-bending torsional interaction equilibrium bond

9、 length bond angle force constant,harmonic function 谐性函数 electrostatic interaction静电相互作用 Morse potential Morse势函数 calcite 方解石 Calcium carbonate 碳酸钙 atomistic modeling 原子模拟,harmonic function electrostatic interaction Morse potential Morse calcite Calcium carbonate atomistic modeling,nevertheless然而 re

10、produce 重现 aragonite phase 文石：结晶富钙碳酸钙的一种正 交晶矿物 emphasis重点 divalent metal dopant 二价金属掺杂物,Nevertheless reproduce aragonite phase Emphasis divalent metal dopant,phosphate 磷酸盐 aluminophosphate 磷酸铝 microporous 微孔性的 orthophosphate正磷酸盐 calcium 钙 magnesium 镁 strontium锶,phosphate aluminophosphate microporous

11、 orthophosphate calcium magnesium strontium,diphosphonate 二磷酸盐 apatite 磷灰石：一种自然的，多色的钙氟化 物磷酸盐 biomineralogy生物矿物学 lithium phosphate glass磷酸锂玻璃 LennardJones potential L-J 势函数 Perchlorate, chlorate and bromate 高氯酸盐、氯酸盐和溴酸盐,diphosphonate apatite Biomineralogy lithium phosphate glasse LennardJones potenti

12、al Perchlorate, chlorate and bromate,stem from起源于 sodium perchlorate高氯酸钠 crystal morphology 晶体形态学 potassium perchlorate高氯酸钾 nitrate 硝酸盐 transferability 可移植性 motivation 目的，动机,stem from sodium perchlorate crystal morphology potassium perchlorate nitrate Transferability motivation,lattice expansion 点阵参

13、数膨胀 molecular dynamics 分子动力学 parameterize 确定的参数 , 用参数表示 parameterisation 参数化 discriminate区别 sulphate 硫酸盐,lattice expansion molecular dynamics Parameterize parameterisation discriminate sulphates,ammonium halide卤化铵 prerequisite to先决条件 ammonium nitrate 硝酸铵 ammonium chloride 氯化铵 ammonium nitrate硝酸铵 loo

14、k at考虑 cross term交叉项,ammonium halides prerequisite to ammonium nitrate ammonium chloride ammonium nitrate look at cross term,refit 重新拟合，整修 phase transition 相变 conclusion结论 diverse不同的, 变化多的 methodology方法学, 方法论,refit phase transition Conclusion Diverse methodology,三、课文的阅读理解,请同学们阅读课文内容，思考和回答下列问题：,1. Wh

15、at does the paper relate to? 2. How to find the other papers which related to this paper? 3. What does “molecular species” mean in this paper? Please explain it in Chinese. Please give the examples for molecular cationic materials and molecular anionic materials,4. What do play an important role in

16、computer modeling? 5. What are interatomic potentials? 6. What is the central aspect of work in computer modeling? 7. What does the Appendix list?,For non-bonded interactions,what potential function are used? 9. For non-bonded interactions,how to obtain the potential parameters? 10. Please describe

17、the potential function for bonded interactions 11. How to get the potential parameters for bonded interactions?,12. What compounds have potential functions? 13. Which compound is probably the most complex molecular ionic solid modelled to date? 14. “The methodology is well established for derivation

18、 of potentials for additional materials.” What does it mean? (Please answer it in Chinese),1. What does the paper relate to?,This review describes recent advances and results achieved in the computer modelling of molecular ionic materials.,2. How to find the other papers which related to this paper?

19、,We can find other papers from “references” and “keywords” in this paper.,3. What does “molecular species” mean in this paper? Please explain it in Chinese. Please give the examples for molecular cationic materials and molecular anionic materials.,4. What do play an important role in computer modeli

20、ng?,The interatomic potentials play an important role in computer modeling.,5. What are interatomic potentials?,Interatomic potentials define the interatomic interactions responsible for cohesion（结合力） in materials.,6. What is the central aspect of work in computer modeling?,To develop the potential

21、functions for the system studied is the central aspect of work in computer modeling. .,7. What does the Appendix list?,The Appendix contains a selection of potential parameters for the materials,8. For non-bonded interactions, what potential function are used?,For non-bonded interactions, how to obt

22、ain the potential parameters?,In most cases, they have been obtained by empirical fitting.,10. Please describe the potential function for bonded interactions,For bonded interactions, the important interactions are bond-stretching, bond-bending and torsional interactions:,11. How to get the potential

23、 parameters for bonded interactions?,Values of force constants have usually been calculated by empirical fitting, but for bond-stretching force constants, experimental spectroscopic values may be available.,Which compounds have potential parameters in this paper?,13. Which compound is probably the m

24、ost complex molecular ionic solid modelled to date?,It is ammonium nitrate.,14. “The methodology is well established for derivation of potentials for additional materials.” What does it mean? (Please answer it in Chinese),Computer modelling of molecular ionic materials 分子离子材料的计算机模拟,Abstract,This rev

25、iew describes recent advances and results achieved in the computer modelling of molecular ionic materials. These materials offer particular challenges in modelling because both ionic and covalent interactions contribute to their interatomic forces, and both are therefore responsible for their proper

26、ties.,Ionic materials have been extensively studied, as have molecular solids, and in modeling molecular ionic materials some techniques from both of these are borrowed and used.,Keywords : Computer modelling; Molecular ionic materials; Ionic / covalent interactions; Interatomic potentials,1. Introd

27、uction,Molecular ionic materials are defined as materials in which either the cation, or the anion, or both, are molecular species.,Molecular anionic materials are typified 代表by calcium carbonate, molecular cationic materials include the ammonium halides, and ammonium nitrate has both molecular anio

28、ns and cations.,Computer modelling relies on the specification of accurate interatomic potentials to define the interatomic interactions responsible for cohesion（结合力） in materials.,Molecular ionic materials, with their balance of ionic and covalent interactions, make particular demands on potentials

29、, and a central aspect of work in this area has been in the development of such potentials.,This review will first describe the interatomic potential model used, putting it in the context of earlier work on ionic materials, and will then go on to describe the materials studied, and the potentials de

30、veloped.,An Appendix containing a selection of potential parameters for the materials is included.,2. Interatomic potential model 相互作用势函数模型,The potential model used is closely related to that used for ionic materials, with necessary adaptations(修改) to model covalent interactions within the molecular

31、 ion group.,For clarity, non-bonded and bonded interactions are considered separately. For non-bonded interactions, the potential has the following form:,Here qi , qj are the charges on ions i and j (which are not part of the same molecular ion), and A, r, and C are parameters whose values are obtai

32、ned for each ion pair.,In most cases, they have been obtained by empirical fitting. It is important to note that the charges of ions which are part of a molecular ion are normally partial charges, with the condition being imposed把.强加给that the molecular ion has a formal charge overall.,For bonded int

33、eractions, the important interactions are bond-stretching, bond-bending and torsional interactions:,Here ka, kb and kt are bond-stretching, bond-bending and torsional force constants, and r0, 0 are equilibrium bond lengths and bond angles, respectively.,Values of force constants have usually been ca

34、lculated by empirical fitting, but for bond-stretching force constants, experimental spectroscopic values may be available.,It should be noted that for bonded interactions defined by the harmonic function given above, electrostatic interactions are not included.,An alternative to the use of a harmon

35、ic potential is the Morse potential, which has been used in some cases, for example in Ref. 4 on calcite.方解石,3. Studies of specific systems,In this section, the specific molecular ionic systems modelled to date will be considered. Since this subject has not been reviewed before, some older work will

36、 be included.,3.1 Calcium carbonate and calcite（碳酸钙和方解石（六方晶系）,Calcium carbonate was the first molecular ionic material to study using atomistic modelling, with three potentials appearing in 1992 13.,These potentials did not distinguish between bonded and non-bonded interactions, employing a Buckingh

37、am potential for the CO interaction.,Nevertheless they were able to reproduce the structure and properties of calcite well, and (they were)transferred well to the aragonite文石（正交晶系）phase.,A refinement to the potential in Ref. 3 appeared in 1996 4, in which the CO interaction was modelled using a Mors

38、e potential, and temperature dependence of the structure was included in the fit.,Similarly, a refinement to Ref. 2, using a harmonic CO interaction has been derived 5. Finally, a new set of potentials was published in 2000 6, in which the emphasis重点 was on providing a consistently derived set of po

39、tentials for metal carbonates and divalent metal dopants. 掺杂物,3.2. Phosphates （磷酸盐）,An alternative treatment was presented for the aluminophosphates, which form microporous 微孔性的solids.,An interesting feature of this potential was the almost unique use of a formal charge for the phosphorous ion 9. Th

40、e orthophosphates, specifically calcium, magnesium and strontium锶, have also been modelled 10.,The apatite(磷灰石) minerals, particular examples of calcium phosphate minerals of importance in biomineralogy生物矿物学, have received recent interest, with potentials adopted being largely based on pre-existing

41、phosphate potentials 11,12.,CaO 54.58%, P2O5 41.36%, F 1.23%, C 12.27%, H2O 0.56%。其F、Cl、OH以等比计算。磷灰石按附加阴离子的不同可分为氟磷灰石（fluorapatite）Ca5PO43F、氯磷灰石（chlorapatite）Ca5PO43Cl、羟磷灰石（hydroxylapatite）Ca5PO43(OH)，它们相互间成类质同象关系。通常以氟磷灰石为常见。,Finally, a recent study of lithium phosphate glasses used a LennardJones pot

42、ential for non-bonded interactions, with a three body potential (see Section 2) for the OPO and POP bonds 13.,3.3. Perchlorates, chlorates and bromates,The interest in perchlorates and chlorates stems from their industrial applications in the agricultural and defence防卫industries.,The main motivation

43、 for the development of potential models has been interest in modelling their morphologies. A potential was developed for sodium perchlorate and subsequently transferred to other alkali metal perchlorates, using the form described in Section 2.,This potential was used to calculate the crystal morpho

44、logy of potassium perchlorate, using both surface and attachment energy附着能approaches 14. A similar approach was used in a study of the alkali chlorates and bromates 15.,In these potentials a Morse potential was used for the ClO and BrO bonded interactions, but otherwise然而在别的方面却followed the form desc

45、ribed in Section 2. These potentials were subsequently used in a morphological形态学的study of sodium chlorate 16.,3.4. Nitrates,Potentials for the nitrate molecular ion have been obtained by fitting to the structure and properties of the -phase of potassium nitrate, and tested for transferability again

46、st the sodium nitrate structure 17.,The main motivation(目的) was to obtain a potential for use in modelling ammonium nitrate (see Section 3.7), however, the potential was additionally tested by modelling the lattice expansion of potassium nitrate using molecular dynamics, and comparing with experimen

47、tal data 18.,3.5. Sulphate,Sulphates, along with carbonates were one of the first molecular ions to be modelled.,Potentials included an early parameterisation that did not discriminate区别between bonded and non-bonded interactions 19, and a detailed study of the divalent metal sulphates 20, where the

48、bonded SO interaction was represented by a Morse potential.,This potential has also been partly reparameterised with a harmonic potential replacing the Morse potential for the SO interaction (see Appendix).,3.6. Ammonium halides,As with the nitrates, the ammonium halides were studied as a prerequisi

49、te to先决条件ammonium nitrate.,A potential was fitted to ammonium bromide, and the ammonium parameters transferred to ammonium chloride, with good reproduction of lattice parameters being achieved 17.,3.7. Ammonium nitrate,Ammonium nitrate is probably the most complex molecular ionic solid modelled to d

50、ate 17.,The potential was developed by looking at（考虑） the anion and cation separately, as explained in Sections 3.4 and 3.6, and then by combining the parameters in a modelling study of the low temperature phase of the material.,It was then necessary only to fit potentials for the cross terms betwee

51、n the hydrogen of the ammonium cation and the nitrogen and oxygen of the nitrate group, and to refit the hydrogenhydrogen non bonded potential.,The resulting potential was tested using molecular dynamics to test its reproduction of the lattice expansion of the low temperature phase up to the phase t

52、ransition; agreement of 2% or better was obtained 18.,4. Conclusions,It can be seen from the examples considered in this review that a diverse不同的, 变化多的range of molecular ionic materials can now be modelled, and moreover, that the methodology is well established for derivation of potentials for addit

53、ional materials.,Particularly, there are good opportunities to model materials combining ammonium and other molecular anions, such as ammonium perchlorate, and other materials of industrial interest.,四、答疑,一般情况下，争对学生提出的问题进行个别答疑。,Translate the technical terms in the paper into Chinese by referring to

54、relevant dictionaries. 2. Please translate the paper into Chinese.,五、课后作业,预习内容：,复习内容： 1、复习和整理本课文的专业词汇； 2、本课文的全文翻译。,X-ray Diffraction using the Transmission Laue Method,六、课堂练习,1、翻译下列词汇：,as per (in accordance with) N/M (neutral mark) T/T (telegraphic transfer) B/L (bill of lading) SRCC (strikes, riot

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57、e expanse insurance premium thereafter,duly shipping duration stipulated dispatch contract number gross weight insurance,Peoples Insurance Company of China consent premium trim incurred packing hereunder,deem stipulate hereof document negotiation memo commercial invoice,manufacturer certificate of o

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