原子键

These results reveal that, as an intrinsic property of the wave function of atoms, the angle of the probability distribution of the angular two-electron density is approximately equal to the bond angle of the molecular which usually can be explained by the hybridization theory.

结果显示，作为原子波函数的内禀性质，双电子密度最可几角分布的角度与通常由分子杂化轨道理论解释的相关原子的分子的结合键角近似相等。

The average bond length between the nearest and second nearest neighbor atoms of the vacancy is 0.15 nm and shortened by 4×10^(-3)nm.

最近邻原子和次近邻原子间的平均键长缩短了约4×10^(-3)nm。

The empty p orbital and the occupied σorbital by a lone electron pair of carbene point towards H atom and C atom of the C—H bond respectively.

卡宾空的p轨道和占有一对孤电子的σ轨道分别指向C—H键的H原子和C原子。

Configurational isomerism is then due to the presence in the molecule of one or more dissymmetric centres ,in the simplest case asymmetric carbon atoms ,each of which can have and absolute configuration; and ,or ,to the presence of double blonds which can give cis- and trans-geometrical isomers .

构型异构是由于分子中存在一个或一个以上的不对称中心，在最简单的情况下是不对称碳原子，每个不对称碳原子的绝对构型是和；或者，如果存在双键的话，那么将给出顺式和反式几何异构体。

Using DFT combined with the orbital localized approach and Xu's covalence new concepts on a molecular fragment, it is concluded that the covalence of copper atom is 7 in 〓-type clusters and in inorganic fullerene-like molecule 〓, and there are Cu-Cu single bonds in 〓-type clusters.

应用DFT结合轨道定域化的方法和分子片共价的新概念，提出了在〓类簇合物和无机类富勒烯分子〓〓中Cu原子的共价为7，以及化合物中Cu-Cu单键的存在；解释了通常认为这类化合物中Cu-Cu之间没有成键作用而又不能回答较短的Cu-Cu键长的问题。

"Olefins may be classified by whether the double Bond is in a ring or a chain or by the number of double Bonds (monoolefin, diolefin, etc.)."

有两种分类方法︰一、分为环烯烃和非环烯烃，双键依次位于成环碳原子之间或开链基团的碳原子之间。

In this study, the octahedron(111), cube(100) and dodecahedron(110) surfaces of diamond have been investigated by quantum chemistry calculations.

对比数据可以知道，在金刚石八面体{111}面上单原子能量最大，原子间所形成的共价键键能最强，所以在该面上物理化学性质最为稳定。

As to thymine, the bond energy of the ion with the most stable tautomer of the free nucleic acid base is the weakest among the three tautomer＇ s complexes, and that of the ion with least stable tautomer of the free nucleic acid base is the strongest .

在互变异构体复合物中，键能是依赖于金属离子成键的位置，而总能量取决于全部的原子和它们之间的相对位置，这可能是造成几种互变异构体复合物键能和总能量变化趋势并不一致的原因。

A new organic compound, trans-2--5-dimesitylborylthiophene (abbreviated as DMASBT, 5) with dimesitylboryl, dimethylamino and styryl-thiophene as electron acceptor, electron donor and conjugate bridge respectively, was synthesized. Its crystal structure determined by X-ray diffraction method indicates that the B-C bond between B atom and it bridge is obviously shorter than those of between B atom and mesityl groups. This remarkably strengthened B-C bonding can be regarded as an evidence of additional p-7t conjugation between the B atom and n bridge.

合成了以含硼基团为电子受体，以二甲胺基为电子给体，以苯乙烯基噻吩为共轭桥的新化合物2-[（4'-N，N-二甲胺基）苯乙烯基]-5-二米基硼-噻吩 trans-2-[(4'-N， N-dimethylamino) styryl]-5-dimesitylboryl-thiophene（简写为DMASBT，5）。X射线衍射方法测定其单晶结构表明，硼原子与π共轭桥之间的硼碳键相对于其它的硼碳键明显缩短，硼与π共轭桥之间存在除了σ键之外的p-π共轭作用。

In addition, there are a large number of strong hydrogenbondings(N-H…O,O-H…O) and weak hydrogen bondings in involving the cations,perchlorate counter-ions,PNOS and water molecules, which result in formation 3-D networkstructure.

晶体中Ni与配体希夫碱中的N 、N(吡吡啶醛类过渡金属希夫碱配合物的合成、晶体结构及谱学表征啶)、O原子配位形成变形的八面体构型，由于分子间，存在大量的强氢键和弱氢键，这些氢键的交互作用使得该配合物形成二维网状结构。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。