Electronic structures and properties of Ti, Zr and Hf metals

Ａｔｒｏｏｍｔｅｍｐｅｒａｔｕｒｅａｎｄａｍｂｉｅｎｔｐｒｅｓｓｕｒｅ ,ｔｈｅｓｔａｂｌｅｃｒｙｓｔａｌｌｉｎｅｓｔａｔｅｏｆｔｈｅｅａｒｌｙｔｒａｎｓｉｔｉｏｎｍｅｔａｌｓＴｉ,ＺｒａｎｄＨｆｉｓａｈｅｘａｇｏｎａｌｃｌｏｓｅ ｐａｃｋｅｄ(ｈｃｐ)ｓｔｒｕｃｔｕｒｅ (αｐｈａｓｅ) .Ａｔｈｉｇｈｔｅｍｐｅｒａｔｕｒｅ ,ａｌｌｔｈｅｓｅｔｈｒｅｅｍｅｔａｌｓｕｎｄｅｒｇｏａｐｈａｓｅｔｒａｎｓｆｏｒｍａ ｔｉｏｎｉｎｔｏａｂｏｄｙ ｃｅｎｔｅｒｅｄｃｕｂｉｃ (ｂｃｃ)ｓｔｒｕｃｔｕｒｅ (βｐｈａｓｅ) …     

Electronic structures and physical properties of pure aluminum metal

By one-atom theory, the electronic structure of pure Al metal with f.c.c, structure has been determined to be [Ne](3s_c)~(1.8790)(3p_c)~(0.4982)(3s_f 3p_f)~(0.6228). According to this electronic structure, the potential curve, lattice constant, cohesive energy, elastisity, and the temperature dependence of the linear thermal expansion coefficients have been calculated. The electronic structures and characteristic properties of Al metals with b. c. c., h.c.p. structures and liquid have been studied. It is argued that the pure Al metal with f. c.c. structure can exist naturally, but with b. c. c.and h. c.p. structures cannot.##属性不符     

反钙钛矿晶体Sc3AlN电子结构和光学性质的第一性原理研究

采用基于密度泛函理论的第一性原理的分子动力学方法,对立方反钙钛矿Sc3AlN的电子结构和光学性质进行了计算．系统分析了Sc3AlN电子结构和成键情况,并利用计算的能带结构和态密度分析了Sc3AlN的介电函数实部和虚部以及由它们派生出来的光学常数,即折射率、反射谱、吸收谱、光电导率和能量损失函数等．计算结果表明Sc3AlN属于导体材料,其价带主要由Al的2s2p,Sc的3d态电子构成,导带主要由Sc的3d态电子构成,静态介电常数ε1（O）=22．1,折射率n（0）=4．7．     

Electronic structures and properties of V, Nb and Ta metals

0　ＩｎｔｒｏｄｕｃｔｉｏｎＴｏｄｅｓｉｇｎａｌｌｏｙｓｓｃｉｅｎｔｉｆｉｃａｌｌｙ ,ｓｙｓｔｅｍａｔｉｃｓｃｉｅｎｃｅｆｒａｍｅｏｆｍｅｔａｌｓａｎｄａｌｌｏｙｓｉｎｃｌｕｄｉｎｇｔｈｅｓｙｓｔｅｍａｔｉｃｓｃｉｅｎｃｅｏｆｐｕｒｅｍｅｔａｌｓ (ｏｎｅ ａｔｏｍ (ＯＡ)ｔｈｅｏｒｙ) [1,2 ]ａｎｄｔｈｅｓｙｓ ｔｅｍａｔｉｃｓｃｉｅｎｃｅｏｆａｌｌｏｙｓ (ｃｈａｒａｃｔｅｒｉｓｔｉｃｃｒｙｓｔａｌ(ＣＣ)ｔｈｅ ｏｒｙ) [3～ 6 ]ａｒｅｅｓｔａｂｌｉｓｈｅｄ ,ｗｈｉｃｈｃａｎｇｉｖｅｄｉａｇｒａｍｓｏｆ…     

稀土掺杂板钛矿相TiO2第一性原理研究

基于第一性原理,以板钛矿相TiO2、稀土/板钛矿相TiO2原胞为基本模型,利用MS4.0软件的castep模块结合ATK软件计算了17种稀土/板钛矿相TiO2的态密度、晶体能、能隙等参数。结果表明：除Sc、Y外,其余稀土元素均有利于降低板钛矿相TiO2的能隙,其与4 f电子结构相对应。Sc和Y利于降低板钛矿相TiO2的晶体能,其利于降低合成所需能量。     

Comparative DFT study of [Mg(CHZ)3](ClO4)2 and [Mg(CHZ)3](NO3)2 (CHZ=Carbohydrazide)

The molecular geometry,electronic structure,thermochemistry and infrared spectra of [Mg(CHZ)3](ClO4)2 and [Mg(CHZ)3](NO3)2 were comparatively studied using the Heyd-Scuseria-Ernzerhof(HSE) screened hybrid density functional with 6-31G** basis set.The experimental results show that the complexes have six-coordinated octahedron feature,and the metal-ligand interactions are predominantly ionic in nature.The calculated heats of formation predict that [Mg(CHZ)3](NO3)2 is more stable than [Mg(CHZ)3](ClO4)2.Detailed NBO analyses indicate that the ligand-anion interaction plays an important role in the stability for these two energetic complexes.Moreover,the stretching vibration frequencies of N-H bonds shift to lower wave number compared to the free CHZ ligand,which are caused by the delocalizations from N-H bond orbital to lone-pair electron antibond orbital of magnesium.     

三核镍配合物[Ni_3(Htrz)_6(H_2O)_6](SO_4)_3·8H_2O的合成与晶体结构

用常规水溶液法合成了三核配合物[Ni3(Htrz)6(H2O)6](SO4)3.8H2O(1),其中Htrz=1,2,4-1H-三氮唑.用X-射线单晶衍射、元素分析、红外光谱、热重分析对晶体结构进行了表征.该晶体属于三斜晶系,P-1空间群,a=11.802(2),b=12.120(3),c=18.663(4),α=71.28(0)°,β=86.66(0)°,γ=62.04(0)°,V=2 219.5(8)3,Z=2,F(000)=1 666,R1=0.1217,wR2=0.360 0.CCDC:831634     

Al3Sc的FFC法制备和第一性原理计算研究

采用熔盐电脱氧法（FFC）制备Al3Sc,并应用以密度泛函理论为基础的平面波赝势方法,利用第一性原理的CASTEP软件包计算了Al3Sc的晶体结构和电子结构．结果表明：物质的量比为3：1的Al2O3和Sc2O3混合阴极片,在700℃、3．2V电解电压下,经20h电解后完全形成Al3Sc．计算了A13sc的晶格常数α=0．411nm,与XRD检测结果符合．     

环金属铱配合物的分子设计

苯并噻吩铱配合物通常发红光,且具有较强的电致发光性能,因此被广泛应用于光电显示领域.以2-(苯并噻吩-2-基)喹啉为基础配体,从理论上研究了3个同分异构体铱[(btq)₂Ir(pic)][btq=2-(苯并噻吩-2-基)喹啉(1);3-(苯并噻吩-2-基)异喹啉(2);1-(苯并噻吩-2-基)异喹啉(3);pic=吡啶甲酸酯]配合物的电子结构和光谱特征.采用B3LYP和Cis方法优化了它们的S₀和T₁态几何结构,利用TD-DFT方法,结合CPCM溶剂模型模拟了它们在CH₂Cl₂溶剂中的吸收和发射光谱.研究结果表明：计算得到的分子结构参数与相对应的实验值吻合得较好.3个配合物的最低能吸收和发射分别在488(1)、455(2)、485(3)和679(1)、642(2)、683 nm(3).其最高占据分子轨道由金属的d轨道和btq配体的π成键轨道占据,而最低空轨道为占据在btq配体上的π反键轨道.因此,最低能吸收和发射均被指认为金属到btq配体(MLCT)和btq配体内部(IlCT)...     

二苄化二硫[PhCH2SSCH2Ph]的合成及晶体结构和热性能分析

通过X-射线单晶衍射,确定了化合物[PhCH2SSCH2Ph]的晶体结构。化合物晶体属于单斜晶系,空间群为C2/c,晶胞参数a=1.351 0(3)nm,b=0.825 94(17)nm,c=1.140 8(2)nm,β=99.35(3)°,z=4。通过S S键桥联2个苄基,2个苄基不在同一个平面上,以S S键为中心扭曲几乎90°。热重分析表明该化合物在260℃完全分解。     

十四元大环镍配合物[NiL](ClO4)2的合成及其晶体结构

利用金属模板法合成了一个新的含对称噻吩基团十四元大环镍配合物[NiL](ClO4)2(L=3,10-二(2-噻吩乙基)-1,3,5,8,10,12-六氮十四元大环多胺,分子式为C20H34N6S2),采用溶剂挥发法培养单晶,通过X-单晶衍射手段对配合物进行了结构解析.     

以喹啉为端基的双酰胺型柔性化合物的合成及配位性能研究

以8-氨基喹啉、己二酸及硫代二丙酸为主要原料,合成了2个新的柔性化合物:N,N′-二(喹啉-8-基)己二酰胺(3a)、N,N′-二(喹啉-8-基)-4-硫杂庚二酰胺(3b),通过元素分析、红外光谱、核磁共振等方法对其结构进行了表征,并研究了这2种化合物与过渡金属的配位性能。结果表明,化合物(3b)可与M(NO3)(M=Co、Ni、Cu、Zn)反应形成配合物,该系列配合物的组成为[M(3b)(NO3)2](M=Co、Ni、Cu、Zn)。而化合物(3a)则不宜与这些金属发生配位反应。     

Existence of solutions of nonlinear two-point boundary value problems for 4nth-order nonlinear differential equation

0　ＰＲＥＬＩＭＩＮＡＲＩＥＳＷｅａｓｓｕｍｅｔｈｒｏｕｇｈｏｕｔｔｈｉｓｐａｐｅｒｔｈａｔ(Ｈ1)Ｔｈｅｆｕｎｃｔｉｏｎ ｆ(ｔ ,ｙ0 ,ｙ1,… ,ｙ4ｎ- 1)ｉｓｃｏｎｔｉｎｕｏｕｓｏｎ [ａ ,ｃ]×Ｒ4ｎ.(Ｈ2 )Ｅｖｅｒｙｓｏｌｕｔｉｏｎｏｆｉｎｉｔｉａｌｖａｌｕｅｐｒｏｂｌｅｍｓｆｏｒｎｏｎｌｉｎｅａｒ 4ｎｔｈ ｏｒｄｅｒｄｉｆｆｅｒｅｎｔｉａｌｅｑｕａｔｉｏｎｙ(4ｎ) =ｆ(ｔ ,ｙ ,ｙ′ ,… ,ｙ(4ｎ- 1) ) ( 1)ｅｘｔｅｎｄｓｔｏ [ａ ,ｃ]ｏｒｂｅｃｏｍｅｓｕｎｂｏｕｎｄｅｄｏｎｉｔｓｇｒｅａｔ ｅｓｔｅｘｉｓｔ…     

Medium-range order clusters in metal melts

Structures of molten metals Cu and Al, alloys Cu-Al, Al-Ni, Al-Fe and, Al-Si were investigated by using high temperature X-ray diffractometer. It has been found that there are not only short-range order structures (SRO) but also medium range order structures (MRO) in Cu-Al, Al-Ni, Al-Fe alloy melts. There are only short-range order structures in the pure metals Cu and Al and Al-Si alloy melts at different temperatures. It has also been found that the presence and the disappearance of the MRO structures in molten metals are a function of temperature. Moreover, the pre-peak in the structure factor is an indication of MRO in molten metals. There is a pre-peak in each structure factor S( Q) of Al-Fe alloy melt containing 14 wt% Fe, 16 wt% Fe and 19 wt% Fe at 1550℃, showing that there are the medium range order structures in these alloy melts. For Al-35wt% Ni alloy, the pre-peak exists in S(Q) when the temperature is lower than 1300?, and it is weakened drastically when the temperature surpasses 1300℃. The     

Synthesis and Characteristic of a New Niobate:Ba_5NaCo_0.5Nb_9.5O_30

A new niobate crystal was synthesized for the first time in BaO-Na2O-Co2O3 -Nb2O5 system by solid state reaction and the flux method. The new compound was studied by X-ray diffraction, electron probe. N-ray microanalysis, chemical analysis and SEM. The result of the X-ray diffraction shows that Ba5 NaCo0.5 Nb9.5 OK) belongs to tetragonal tungsten bronze structure with space group P4bm( 100) and lattice parameters a = b = 12.4453(2) A, c = 3. 9770 (3) A and Z = 1. The structure of the compound is different from that of Ba4Na2Nb10O30     

The effect of hydrogen on the electronic structure of kink in bcc iron

The electronic structures of kinks in the [100](010) and 1/2[111](−110) edge dislocations in bcc iron containing hydrogen are investigated by means of the first-principles DMol method and the discrete variational method. The effects of hydrogen on the kinks are discussed. The results show that hydrogen forms weak bonding states with its neighboring host atoms, and since hydrogen draws charge from its neighboring host atoms, the interactions between most of the host atoms are weakened compared with those of the corresponding atomic pairs in the clean kinks. This indicates that the migration of kink, i.e. the motion of dislocation, is easier in the doping hydrogen kink than in the clean kink, which may be the solid solution softening effect resulting from the impurity hydrogen. Supported by the National Basic Research Program of China (Grant No. 2006CB605102) and Science Foundation of Central South University of Forestry & Technology (Grant No. 06y016)     

四氯化铁合四丁基胺化合物的合成和晶体结构表征

合成了标题化合物[n-Bu4N]+[FeCl4]-,并通过元素分析和X-射线单晶衍射对其结构进行了表征。晶体属于正交晶系,空间群Pnna,晶胞参数为:a=1.851 0(4)nm,b=1.155 3(2)nm,c=1.144 2(2)nm,V=2.446 8(8)nm3,Z=8,Dc=1.195 g.cm-3,F(000)=932,μ=1.051 mm-1。化合物由一个独立的[FeCl4]-阴离子和一个独立的[n-Bu4N]+阳离子组成。在[FeCl4]-阴离子中,中心的铁原子与4个氯离子配位,形成一个扭曲的四面体构型,Fe Cl键键长分别为0.212 2(14)nm和0.218 07(17)nm。在[n-Bu4N]+阳离子中,氮原子同样处于一个扭曲的四面体构型。在固体状态下,独立的[FeCl4]-阴离子和[n-Bu4N]+阳离子通过弱的C H…Cl分子间相互作用力使晶体结构得以稳定。     

含N杂环硫醚四核Cu（I）配合物的合成及晶体结构

采用溶液扩散法,利用含N杂环硫醚配体2-巯基-(2-甲基吡啶)-4-甲基嘧啶(L)和金属盐CuI反应合成了配合物[Cu₄I₄L₂],利用X线单晶衍射技术测定了其晶体结构,并对其进行了红外表征.结果表明,该配合物属单斜晶系,空间群为P2₁/n,晶胞参数:a=1.004 70(5) nm,b=0.893 04(4) nm,c=1.815 98(8) nm,β=99.847(10)°,V=1.605 36(13) nm³,Z=2,Mr=1 196.40.该配合物为四核结构,配合物分子间通过氢键、S…S和π-π等弱作用堆积成三维结构.     

Crystal growth,structure and properties of bismuth triborate BiB3O6 crystal

BiB3O6(BIBO) single crystals with size of 46×23×10 mm3 and weight of 26.0 g have been successfully grown by top-seeded method. Problems encountered in the growth process of this crystal have been discussed in detail, and the methods of growing high-quality large crystals have been put forward. The relationship between their structure and properties is studied. The space group of monoclinic BiB3O6 is C2 and the cell parameters are a = 7.1203(7)(?), b = 4.9948(7)(?), c = 6.5077(7) (?), β= 105.586(8)", and V = 222.93(5)(?)3. The density of BIBO is4.8965 g/cm3. The Mohs's scale of hardness is 5.5-6. There is no cleavage face in the crystal. The transmittance of BIBO is about 80 percent in the range from visible coherent light to near-infrared light. The ultraviolet cutoff wavelength is at 276 nm. BiB3O6 is a biaxial crystal and has two sets of axes, and the relative orientation of ( X, Y, Z) with regard to (a, b, c) is: X//b, ( Y, c) =47.2°, (Z, a) = 31.6°, determined by X-ray analysis combined with pol     

Electronic structure of FCC phase in Fe-Mn-Si based shape memory alloys and its stability

The relationship between the electronic structure of FCC phase in Fe-Mn-Si alloy and its stability has been studied by using the discrete variational method based on the first principle. The reason why Mn and Si elements have different influences on the stacking fault energy may be related to the electron concentration ( e/a). Si reduces the hole number of 3d band while Mn is rather complicated . The binding energy has been calculated and the experimental results that martensite start temperature (Ms) varies with Si and Mn are explained. When the external stress is exerted in three directions, the electronic structure, the total density of states, the energy gap at Fermi energy level( EF) and the energy degeneracy will change into other states. When the different external stresses are exerted in one direction, 3d or 4s orbital occupations of the central atom decrease, the partial density of states seems to be thinner and its peak increases at EF, the bond orbit shrinks in the direction of the external st