PuO3和PuO+3的分子结构与分子光谱

用相对论有效原子实势RECP和密度泛函(B3LYP, BHANDHLYP)、HF方法对PuO3的分子结构与分子光谱进行了研究.计算比较了C2v, D3h, C3v等构型以及计算方法等对PuO3分子能量和平衡结构的影响,结果表明中性的PuO3能够稳定存在,基态结构为C2v,状态为7B1 (B3LYP R1＝0.19143 nm, R2(＝R3)＝0.22057 nm, ∠OPuO＝102.2108°),比较而言PuO3分子还可能存在D3h结构的亚稳态7A2″,不存在稳定的C3v结构的PuO3分子.计算还同时首次给出了不同多重性的PuO3分子及其一价正离子PuO+3完整的能量、平衡几何结构、光谱数据、电荷布居、自旋密度、极化率与电偶极矩等系列数据.     

基态UC2分子的结构和势能函数

采用密度泛函理论(DFT)的B3LYP方法和相对论有效原子实势理论模型(RECP),对UC2分子可能的结构进行优化计算,得到UC2分子稳定构型为角形C-U-C(C2v);由微观可逆性原理,判断了UC2分子的离解极限;并且导出了基态UC2分子(X 5B1)的多体项展式势能函数,其势能面等值图展现了C-U-C(C2v)稳定结构;根据势能面等值图,讨论了C+UC(X 3П)反应和U+C2(X 1∑+g)反应的势能面静态特征.     

基态Li2O＋分子的结构和势能面研究

以6-311＋＋G(d)为基函数, 采用CASSCF方法优化出Li2O＋分子的稳定构型为线形Li-O-Li (C∞V), 电子组态为2∏, 并对平衡核间距、离解能和基态简正频率进行了计算. 根据原子分子反应静力学原理, 导出了Li2O＋分子的合理的离解极限. 并运用多体展式理论方法首次导出了基态Li2O＋分子的分析势能函数, 绘出了势能等值图, 其势能等值图准确地再现了Li2O＋分子的平衡结构特征.     

PuC和PuC2的分子结构与势能函数

采用密度泛函B3LYP方法和相对论有效原子实理论模型优化出PuC和PuC2分子稳定构型,其电子状态分别为X5Σ－和X5A2.PuC2分子为C2v构型,其∠CPuC=147.67°,平衡核间距Re=0.22819 nm, 离解能De=5.543 eV, 并计算出谐振动频率:ν1=61.736 cm－1、ν2=229.894 cm－1、ν3=305.582 cm－1.在此基础上,运用多体项展式理论方法,导出了基态PuC2分子的分析势能函数,该势能面准确地再现了PuC2分子的稳定结构,并根据势能面等值图讨论了PuC＋C反应和Pu＋C2反应的势能面静态特征.     

LaH2分子基态（C2V,X2A1）的势能函数

在QCISD水平上基于相对论紧致有效势（RCEP:Relativistic Compact Effective Poten-tial)方法优化出的LaH2分子的基态为C2v(X2A1)构型,其∠HLaH=124.4°、平衡核间距Re=2.1945A和离解能De=5.599eV,并计算出谐振频率：v1=1216.521cm-1、v2=1087.417cm-1和v3=2156.9572cm-1。在此基础上,应用多体项展式理论,导出了基态LaH2的分析势能函数,该势能表面准确地再现了LaH2(C2v)平衡结构,并根据势能函数等值图讨论了H+LaH反应和La+H2反应的势能面静态特征,结果表明在La+H2通道上存一个能垒为1.6eV的鞍点,而H+LaH反应通道是无阈能的。     

PuN和PuN_2基态分子的结构与势能函数

用相对论有效原子实势和密度泛函理论方法对PuN和PuN_2分子的结构进行优化 ，得到了其平衡几何构型和谐振频率。采用最小二乘法拟合出PuN基态分子的 Murrell-Sorbie解析势能函数，在此基础上推导出光谱数据和力常数，并用多体展 式理论导出PuN_2基态分子的解析势能函数，正确地反映了其平衡构型特性。     

PuX2+(X=O,H,N,C)分子离子的势能函数与稳定性

用密度泛函B3LYP方法对PuX2+(X=O,H,N,C)分子离子进行了理论研究,结果表明:PuO2+,PuH2+,PuN2+和PuC2+分子离子能稳定存在,基态电子状态是X5∑-(PuO2+),X8∑-(PuH2+),X4∑+(PuN2+)和X9∑-(PuC2+),势能函数为Murrell-Sorbie势函数,并导出了相应的几何性质,力学性质和光谱数据.     

线性簇合物SC_(2n)S~(2-)(n=1～12)电子吸收光谱

应用密度泛函理论,在B3LYP/6-31G水平上优化了线性簇合物SC2nS2-(n=1～12)的基态平衡几何结构,并计算了它们的谐振动频率.在基态平衡构型下,通过TD-B3LYP/cc-pvTZ和TD-B3LYP/cc-pvDZ计算,确定了簇合物SC2nS2-(n=1～10)X1Σ g→11Σ u电子跃迁的垂直激发能和对应的振子强度.基于计算结果,导出了X1Σ g→11Σ u电子跃迁吸收波长与体系大小n的解析关系式,以及SC2nS2-体系第一电离能与体系大小n的解析表达式,并讨论了不同端位原子对碳链体系激发态性质的影响.     

PdH2、YH2分子的结构与势能函数

用密度泛函理论的B3LYP方法,对钯和钇原子采用SDD收缩价基函数,氢原子采用6-311＋＋G**全电子基函数,对PdH2和YH2体系的结构进行优化计算,得到PdH2分子最稳态为C2v构型,电子组态为1A1,平衡核间距RPdH=0.1692 nm,键角∠HPdH=29.4°,离解能De=5.5212 eV,基态简正振动频率:ν1(b2)=1470.1 cm－1、ν2(a1)=1007.9 cm－1、ν3(a1)=2907.0 cm－1.YH2分子最稳态也为C2v构型,电子组态2A1,RYH=0.1962 nm,∠HYH=114.3°,De=5.6691 eV,基态简正振动频率:ν1(b2)=1457.9 cm－1、ν2(a1)=476.0 cm－1、ν3(a1)=1506.3 cm－1.由微观过程的可逆性原理分析了分子的可能离解极限.并用多体项展式理论方法分别导出基态PdH2和YH2分子的势能函数,其等值势能面图准确地再现了PdH2和YH2分子的结构特征和离解能,由此讨论了Pd ＋ H2和Y ＋ H2分子反应的势能面静态特征.     

OUH体系的结构和分析势能函数

采用密度泛涵B3LYP方法优化出了OUH分子的各种结构，确定了最稳定构型和离解能，以及它们的谐性力常数，并导出双原子分子UH,UO的Murrell-Sorbie势能函数及其光谱数据。采用多体项展式方法，导出OUH(X^4A')基态分子的分析势能函数，获得OUH(X^4A')体系的势能面，考察了这个势能函数的基本性质，正确地复现出OUH分子的平衡结构特征，结果表明：U+OH,O+UH,H+UO的反应均为无阈能的放热能反应。为进一步探讨OUH体系的反应动力学过程打下了基础。     

Ground state potential energy curve and dissociation energy of MgH

New high-resolution visible emission spectra of the MgH molecule have been recorded with high signal-to-noise ratios using a Fourier transform spectrometer. Many bands of the A 2Pi-->X 2Sigma+ and B' 2Sigma+-->X 2Sigma+ electronic transitions of 24MgH were analyzed; the new data span the v' = 0-3 levels of the A 2Pi and B'2Sigma+ excited states and the v'=0-11 levels of the X 2Sigma+ ground electronic state. The vibration-rotation energy levels of the perturbed A 2Pi and B' 2Sigma+ states were fitted as individual term values, while those of the X 2Sigma+ ground state were fitted using the direct-potential-fit approach. A new analytic potential energy function that imposes the theoretically correct attractive potential at long-range, and a radial Hamiltonian that includes the spin-rotation interaction were employed, and a significantly improved value for the ground state dissociation energy of MgH was obtained. The v'=11 level of the X 2Sigma+ ground electronic state was found to be the highest bound vibrational level of 24MgH, lying only about 13 cm(-1) below the dissociation asymptote. The equilibrium dissociation energy for the X 2Sigma+ ground state of 24MgH has been determined to be De=11104.7+/-0.5 cm(-1) (1.37681+/-0.00006 eV), whereas the zero-point energy (v'=0) is 739.11+/-0.01 cm(-1). The zero-point dissociation energy is therefore D0=10365.6+/-0.5 cm(-1) (1.28517+/-0.00006 eV). The uncertainty in the new experimental dissociation energy of MgH is more than 2 orders of magnitude smaller than that for the best value available in the literature. MgH is now the only hydride molecule other than H2 itself for which all bound vibrational levels of the ground electronic state are observed experimentally and for which the dissociation energy is determined with subwavenumber accuracy.     

Analytical Potential Energy Function for the Ground State(C2V,A1)of LaH2

The present work has derived analytical potential energy function for the ground state(C2V,A1) of LaH2.In the first place,the electronic state and it’s reasonable dissociation limits are correctly determined based on Atomic and Molecular Reaction Statics(AMRS),and then,using the relativisti ccompact effective potential(RCEP)for La,the equilibrium geometry,dissociation energy and harmonic frequencies for LaH2 have been calculated by ab initio method,the reasults show that RLaH=2.1945?,∠HLaH=124.4°and De=5.599eV,and v1,v2 and v3 are 1216.521,1087.417 and 2156.957cm-1,recpectively.Molecular reaction kinetic of La+H2 and La+H based on this potential energy function is under the way.     

PuOn+的势能函数的稳定性

用密度泛函B3LYP方法对PuOn+（n=1,2,3）分子离子进行了理论研究,结果表明,PuO+\PuO2+分子离子能稳定存在,电子状态是Χ6Σ-(PuO+)、Χ5Σ-(PuO2+)、9Σ-(PuO2+)、7Σ-(PuO2+).导出了相应的几何性质、力学性质和光谱数据,PuO3+分子离子不能稳定存在。     

Ground and excited state dissociation dynamics of ionized 1,1-difluoroethene

The kinetic energy release distributions (KERDs) for the fluorine atom loss from the 1,1-difluoroethene cation have been recorded with two spectrometers in two different energy ranges. A first experiment uses dissociative photoionization with the He(I) and Ne(I) resonance lines, providing the ions with a broad internal energy range, up to 7 eV above the dissociation threshold. The second experiment samples the metastable range, and the average ion internal energy is limited to about 0.2 eV above the threshold. In both energy domains, KERDs are found to be bimodal. Each component has been analyzed by the maximum entropy method. The narrow, low kinetic energy components display for both experiments the characteristics of a statistical, simple bond cleavage reaction: constraint equal to the square root of the fragment kinetic energy and ergodicity index higher than 90%. Furthermore, this component is satisfactorily accounted for in the metastable time scale by the orbiting transition state theory. Potential energy surfaces corresponding to the five lowest electronic states of the dissociating 1,1-C2H2F2+ ion have been investigated by ab initio calculations at various levels. The equilibrium geometry of these states, their dissociation energies, and their vibrational wavenumbers have been calculated, and a few conical intersections between these surfaces have been identified. It comes out that the ionic ground state X2B1 is adiabatically correlated with the lowest dissociation asymptote. Its potential energy curve increases in a monotonic way along the reaction coordinate, giving rise to the narrow KERD component. Two states embedded in the third photoelectron band (B2A1 at 15.95 eV and C2B2 at 16.17 eV) also correlate with the lowest asymptote at 14.24 eV. We suggest that their repulsive behavior along the reaction coordinate be responsible for the KERD high kinetic energy contribution.     

Potential Energy Function for State X1∑+ of LaH

The present work has derived the potential energy function for the ground state X1∑+of LaH in Murrell-Sorbie function form. In the first place, the electronic state and it′ s rea sonable dissodation limits are correctly determined based on Atomic and Molecular Reaction Statics (AMRS), and then, using the relativistic compact effective potential (RCEP) for La, the equilibrium geometry and dissociation energy for LaH have been calculated by the QCISD method. The calculated results for Re'De' Be' αe' ωe and ωexe are 2.125A, 2.623eV,3.7333cm-1, 0.0723 cm-1, 1461.73cm-1 and 21.383cm-1 respectively, which are in good agreement with experimental or calculated values in references.     

CuC、CuN分子基态的结构与分析势能函数

在Cu 的有效核势近似下, 运用密度泛函(B3LYP)方法, 对Cu采用基集合LANL2DZ, 但对其价电子基组的p轨道函数部分做了必要的修改, 而对C、N采用基集合6-311+G(d), 对CuC和CuN分子的微观结构进行了理论计算. 优化并计算了两分子基态的能量, 平衡结构和谐振频率. 根据原子分子反应静力学原理, 导出了CuC和CuN分子基态的合理离解极限和离解能. 应用密度泛函(B3LYP)方法扫描了CuC和CuN分子基态的势能曲线, 并采用最小二乘法拟合了两分子基态的Murrell-Sorbie势能函数及其在平衡位置附近的Dunham展开式. 同时根据Herzberg 和Dunham的公式, 计算了CuC和CuN分子基态的光谱参数.