水分子在不同电荷态的重离子作用下的离化作用

运用舍时密度泛函理论和局域密度近似方法，计算了水分子H2O在速度为12．5a0／fs的重离子C^＋和C^2＋作用下产生的各种电荷态的水分子离子的几率，平均逃逸电子敷和偶极矩的变化随时间的演化，计算结果表明，在重离子势最大时，电偶极矩的变化最大；重离子远离分子时，重离子的电荷态越高，产生高电荷态分子的几率反而越小。     

水分子在不同电荷态的重离子作用下的离化作用

运用含时密度泛函理论和局域密度近似方法,计算了水分子H2O在速度为12.5 a0/fs的重离子C+和C2+作用下产生的各种电荷态的水分子离子的几率,平均逃逸电子数和偶极矩的变化随时间的演化.计算结果表明,在重离子势最大时,电偶极矩的变化最大;重离子远离分子时,重离子的电荷态越高,产生高电荷态分子的几率反而越小.     

Studies on Electronic Structure and Magnetic Properties of an Organic Magnet with Metallic Mn2+ and Cu2+ Ions

The electronic structure and the magnetic properties of the non-pure organic ferromagnetic compound MnCu(pbaOH)(H2O)3 with pbaOH = 2-hydroxy-1, 3-propylenebis (oxamato) are studied by using the density-functional theory with local-spin-density approximation. The density of states, total energy, and the spin magnetic moment are calculated. The calculations reveal that the compound MnCu(pbaOH)(H20)3 has a stable metal-ferromagnetic ground state, and the spin magnetic moment per molecule is 2.208 μB, and the spin magnetic moment is mainly from Mn ion and Cu ion. An antiferromagnetic order is expected and the antiferromagnetic exchange interaction of d-electrons of Cu and Mn passes through the antiferromagnetic interaction between the adjacent C, O, and N atoms along the path linking the atoms Cu and Mn.     

Studies on Electronic Structure and Magnetic Properties of an Organic Magnet with Metallic Mn^2＋ and Cu^2＋ Ions

The electronic structure and the magnetic properties of the non-pure organic ferromagnetic compound MnCu(pbaOH)(H2O)3 with pbaOH=2-hydroxy-1, 3-propylenebis (oxamato) are studied by using the density-functional theory with local-spin-density approximation. The density of states, total energy, and the spin magnetic moment are calculated. The calculations reveal that the compound MnCu(pbaOH)(H2O)3 has a stable metal-ferromagnetic ground state, and the spin magnetic moment per molecule is 2.208 μa, and the spin magnetic moment is mainly from Mn ionand Cu ion. An antiferromagnetic order is expected and the antiferromagnetic exchange interaction of d-electrons of Cu and Mn passes through the antiferromagnetic interaction between the adjacent O, 0, and N atoms along the path linking the atoms Cu and Mn.     

碱金属团簇Na2在重离子作用下的离化

在时间相关的局域密度近似理论框架下研究了重离子Ar8+ 和碱金属团簇Na2 随时间演化的相互作用 .给出了电子系统的总能量 ,产生Na2 的各种电荷态的几率和Na2 价电子的平均逃逸数等物理量随时间的演化 ,进而得到了Na2 的离化几率 .在快重离子与团簇作用中 ,可以得到低激发态的团簇离子. Based on the Time Dependent Local Density Approximation(TDLDA), the processes of excitation of sodium clusters by highly charged Ar 8+ions are simulated. The time-dependent probabilities of escaped electrons are obtained, furthermore, the ionization probabilities of the Na 2clusters are deduced.In fast ion-cluster collisions, Na 2cluster ions can be produced with minimum or even no excitation of the cluster itself     

重离子辐射植物的诱变效应研究及应用

重离子生物技术已引起人们的广泛关注， 植物育种是重离子生物技术研究和应用的热点之一。 简要介绍了重离子的基本特征和在育种应用中的优势， 综述了重离子辐射对植物分子、 细胞、 个体3个水平的诱变效应研究及重离子辐射育种取得的进展。 Heavy ion biotechnology has received much attention since the mid 1980s, when the first mutagenic effect of heavy ion beams was found in rice. Since then, plant breeding is one of the focuses in heavy ion biotechnology. In this paper we outlined the recent developments in plant breeding by heavy ion beams. We introduced briefly the essential characteristics and superiority of heavy ion beams applied in plant breeding, and reviewed further the mutagenic research in three levels(e.g., molecular, cell and individual) of plants. At last, we summarized artificial mutants obtained in plants irradiated by heavy ion beams.     

Electronic and Magnetic Properties of Double Perovskite Ca2CrSbO6

First-principles calculations have been performed for the study of the electronic band structure and ferromagnetic properties of double perovskite Ca2CrSbO6. The density of states, total energy, spin magnetic moment, and charge density were calculated and analyzed in details. It is found that Ca2CrSbO6 has a stable ferromagnetic ground state and the spin magnetic moment per molecule is about 2.99#B. The chromium contributes the most in the total magnetic moments. The results indicate that Ca2CrSbO6 is half-metallic.     

重离子注入生物和药物分子的质量沉积研究技术

介绍了我国在重离子束生物学这门新兴交叉学科领域已经取得的一系列领先成果 ,首次提出了重离子束生物效应系能量沉积、质量沉积、电荷交换和动量传递四者综合作用的结果 .过去的研究已初步证实了重离子注入生物和药物小分子所引起的质量沉积过程 ,并在此基础上开展了重离子注入生物和药物分子改性的研究 .将来可先应用稳定性和放射性重离子束注入生物和药物分子 ,然后用X射线衍射、电子显微镜放射自显影和图像处理等技术对重离子注入质量沉积开展进一步的研究. Heavy ion beam biology is a jumped up scientific subdivision. China acquired a series of prior achievements and for the first time brought forward the idea that heavy ion biological effects are the integrated results of the four effects, i. e. energy deposition, mass deposition, charge exchange and momentum transfer. Researchers have validated the mass deposition process in small biomolecules and pharmic molecules induced by heavy ion implantation, and researches on modification of...     

Quantum Chemical Calculations on 4-[2-(Tert-Butylamino)-1-Hydroxyethyl]-2-(Hydroxymethyl)Phenol by Density Functional Theory

Density functional theory (DFT) calculations have been carried out for the compound 4-[2-(tert-butylamino)-1-hydroxyethyl]-2-hydroxymethyl) phenol (4BAHEHMP) by using the B3LYP method at the 6-311++G (d,p) basis set level. The electric dipole moment (μ) and the first hyperpolarizability (α) values of the investigated molecule were computed. Total and partial density of state (TDOS and PDOS) and also overlap population density of state (COOP or OPDOS) diagrams analysis were presented. HOMO and LUMO energies confirm that charge transfer occurs within the molecule. In addition Molecular Electrostatic Potential (MEP), Natural Bond Orbital analysis (NBO) and Non- Linear Optical (NLO) properties are studied.     

High-order harmonic generation and multi-photon ionization of Na2 in laser fields

In this paper high-order harmonic generation （HHG） spectra and the ionization probabilities of various charge states of small cluster Na2 in the multiphoton regimes are calculated by using time-dependent local density approximation （TDLDA） for one-colour （1064 nm） and two-colour （1064 nm and 532 nm） ultrashort （25 fs） laser pulses. HHG spectra of Na2 have not the large extent of plateaus due to pronounced collective effects of electron dynamics. In addition, the two-colour laser field can result in the breaking of the symmetry and generation of the even order harmonic such as the second order harmonic. The results of ionization probabilities show that a two-colour laser field can increase the ionization probability of higher charge state.     

外电场作用下乙炔分子的激发态研究P

本文采用密度泛函方法(B3LYP)和组态相互作用原理(CIS)在6-311++G**水平上研究了外电场对乙炔分子的激发态的影响规律,结果表明,外电场的大小和方向对乙炔分子的激发态都有明显的影响,沿分子方向的外加电场对分子偶极矩的影响比垂直于分子方向的外加电场更大.     

外电场下CdSe的基态性质和光谱特性研究

采用密度泛函(DFT)B3PW91方法在Lanl2dz基组下优化得到CdSe分子的基态稳定构型, 并研究了外电场对CdSe基态分子的总能量、HOMO能级、LUMO能级、能隙、电偶极矩μ、电荷布居、红外光谱的影响. 在相同的基组下用TD-DFT 方法计算了外电场下CdSe分子的前9个激发态的激发能、激发波长和振子强度. 结果表明: 无电场时CdSe分子的激发波长与实验结果符合较好, 相应的激发能也很接近. 随着电场增加, CdSe基态分子键长、偶极矩、红外谱强度先减小后增大; HOMO能级、LUMO能级、能隙随电场增加而减小; 总能量、谐振频率则是先增大后减小. 此外, 外电场对CdSe分子的激发能, 激发波长和振子强度均有较大影响.     

电子激发和溶剂效应对芴酮-甲醇分子间氢键增强现象的理论研究 (cited: 1)

理论研究了电子激发和溶剂效应导致的芴酮-甲醇复合体系中分子间氢键增强现象．通过基态和激发态性质的计算,不仅展示了分子间氢键键长的变化以及变化在振动光谱中的影响,而且揭示了导致氢键变化的内在物理机制：溶质分子的电子激发及溶剂化效应引起的电子重新分布,增大了溶质和溶剂分子的偶极矩,导致了它们之间的相互作用的增大,并最终加强了分子间氢键的强度．还分别对处于液相及气相中的复合体的基态和激发态的几何结构、红外谱、复合体及构成分子的偶极矩进行了理论计算,结果阐明了电子激发与溶剂化效应对氢键变化的贡献,同时还发现只有进一步引入溶剂化效应,复合体的基态、激发态的性质才能与实验达到精确一致．所有激发态均采用所开发的基于含时密度泛函理论解析计算一阶、二阶激发态能量导数的方法．     

激光偏振特性对丙酮和氧气多光子电离质谱信号的影响

在极性分子丙酮复合物CH3COCH3*H2O和非极性分子氧气的REMPI谱中,母体离子信号强度与激光偏振方向的关系是不同的.改变532 nm激光偏振方向,记录了两种分子母体离子信号强度,实验结果表明,对于氧气分子的母体离子信号强度,激光偏振方向的改变对其没有影响,而对于CH3COCH3*H2O的母体离子信号强度,随偶极矩与激光偏振方向夹角的增加,其母体离子信号强度呈余弦曲线变化,且与夹角余弦的2.1次幂成正比.理论分析显示,CH3COCH3*H2O的REMPI母体离子信号强度应与此夹角的余弦的2次幂成正比.这就说明实验结果和理论分析是相符的.     

Second-harmonic generation from simple metal surfaces and from adsorbed alkali monolayers

The nonlinear surface polarization which is primarily responsible for the surface sensitivity of optical second-harmonic generation, has recently been calculated for various simple metal surfaces and for thin adsorbed alkali overlayers. These calculations are based on the time-dependent density functional approach, i.e. the details of the ground state electron distribution at the surface as well as the self-consistent response to the applied electromagnetic field are fully taken into consideration. The nonlinear dipole moment of the induced surface charge exhibits characteristic spectral features which are closely related to corresponding features shown by the linear dipole moment.     

Photoinduced Intramolecular Charge Transfer in Donor-acceptor Dyad and Donor-bridge-acceptor Triad

在fullerene-PBTDP-TPA三体体系中的光诱导的分子内电荷转移的实验基础上，分别利用密度泛函理论和含时密度泛函理论以及结合二维、三维实空分析方法对fullerene、PBTDP-TPA二体以及fullerene-PBTDP-TPA三体的基态和激发态的性质进行了理论研究．二维定点表象揭示了激发情况下电子和空穴的相干情况．三维跃迁矩阵展示了跃迁偶极矩的方向和强度，而且三维电荷差密度给出了光诱导的分子内电荷转移的方向和结果．同时，用二维和三维表象的方法对fullerene-PBTDP-TPA三体中光诱导的分子内电荷转移过程进行了验证，揭示了在给予者-桥-接收者三体分子体系中分子内激发时电荷转移的机制．除此之外，还发现直接从给予者到接收者超交换的分子内电荷转移极大地促进了给予者-桥-接收者三体分子体系内的电荷转移．     

Adsorption Regularity and Characteristics of sp~3-Hybridized Gas Molecules on Anatase TiO_2(101) Surface

We report the anatase titanium dioxide(101) surface adsorption of sp~3-hybridized gas molecules,including NH_3,H_2O and CH_4,using first-principles plane-wave ultrasoft pseudopotential based on the density functional theory.The results show that it is much easier for a surface with oxygen vacancies to adsorb gas molecules than it is for a surface without oxygen vacancies.The main factor affecting adsorption stability and energy is the polarizability of molecules,and adsorption is induced by surface oxygen vacancies of the negatively charged center.The analyses of state densities and charge population show that charge transfer occurs at the molecule surface upon adsorption and that the number of transferred charge reduces in the order of N,O and C.Moreover,the adsorption method is chemical adsorption,and adsorption stability decreases in the order of NH_3,H_2O and CH_4.Analyses of absorption and reflectance spectra reveal that after absorbed CH_4 and H_2O,compared with the surface with oxygen vacancy,the optical properties of materials surface,including its absorption coefficients and reflectivity index,have slight changes,however,absorption coefficient and reflectivity would greatly increase after NH_3 adsorption.These findings illustrate that anatase titanium dioxide(101) surface is extremely sensitive to NH_3.     

Fully conjugated push–pull dendrons with high dipole moments in excited state; synthesis and theoretical rationalization

Novel fully conjugated push–pull dendrons were synthesized by a divergent approach to evaluate the performance of non‐conventional architectures like dendritic one in charge separation processes associated with photovoltaic events. The dipole moments in excited state were estimated by the solvatochromic method, to be related to the charge separation efficiency. A 1:2 ratio of donor–acceptor groups (methoxy and nitro groups respectively) promotes the largest dipole moment in both ground and excited state (up to 17 D), due to the efficient electron density transfer over the entire molecule, through the π‐electron system. The synthesized dendrons induce charge transfer on excitation as follows from UV–vis absorption–emission analysis and theoretical calculations. Copyright © 2015 John Wiley & Sons, Ltd.     

二氢化钚分子激发态结构的外场效应

采用密度泛函(DFT)方法B3LYP/Gen，在Pu为SDD基组、H为6-311++G^**基组水平上优化得到了分子轴方向不同电偶极场(-0.005—0.005a.u.)作用下，二氢化钚的基态电子状态、几何结构、电偶极矩和分子总能量.在优化构型下用同样的基组采用含时密度泛函(TDDFT)方法(TD-B3LYP)研究了同样外电场条件下对二氢化钚的激发能和振子强度的影响.计算结果表明，分子几何构型与电场大小和方向呈现较强的依赖，电场强度增加基态偶极矩随电场强度线性增加，H-Pu-H的角度线性减小，分子总能量线性减小；激发能随电场强度增加而减小，且对电场方向的依赖呈现近似对称性，满足Grozema关系.电场对振子强度的影响比较复杂，但仍满足跃迁选择定则. 关键词： 二氢化钚 激发态 电偶极场 TD-DFT     

强外电场作用下二甲基硅酮的分子结构和激发态

采用密度泛函(DFT)方法B3P86在6 311++G(d,p)基组水平上优化得到了分子轴方向不同电偶极 场(-0.04～0.04a.u.)作用下,二甲基硅酮的基态电子状态、几何结构、电偶极矩和分子总能量.在优化构型下 用同样的基组采用杂化CIS DFT方法(CIS B3P86)研究了同样外电场条件下对二甲基硅酮的激发能和振子强度 的影响.计算结果表明,分子几何构型与电场大小和方向呈现强烈的依赖,正向电场下基态偶极矩随电场强度线 性增加,分子总能量降低,当反向电场大于0.03a.u.时,偶极距方向改变,总能量增加;激发能随电场增加急剧减 小,且对电场方向的依赖呈现出不对称性,满足Grozema关系.电场对振子强度的影响比较复杂,但仍满足跃迁选 择定则.