Configuration interaction calculations on the spectroscopic and transition properties of magnesium chloride

The potential energy curves(PECs) of 14 Λ–S states for magnesium chloride(Mg Cl) have been calculated by using multi-reference configuration interaction method with Davidson correction(MRCI + Q). The core-valence correlation(CV), scalar relativistic effect, and spin–orbit coupling(SOC) effect are considered in the electronic structure computations.The spectroscopic constants of X~2Σ~+ and A ~2Π states have been obtained, which are in good agreement with the existing theoretical and experimental results. Furthermore, other higher electronic states are also characterized. The permanent dipole moments(PDMs) of Λ–S states and the spinorbit(SO) matrix elements between Λ–S states are also computed. The results indicate that the abrupt changes of PDMs and the SO matrix elements are attributed to the avoided crossing between the states with the same symmetry. The SOC effect is taken into account with Breit–Pauli operator, which makes the 14Λ–S states split into 30 ? states, and leads to a double-well potential of the ? =(3)1/2 state. The energy splitting for the A2Π is calculated to be 53.61 cm~(-1) and in good agreement with the experimental result 54.47 cm~(-1). The transition dipole moments(TDMs), Franck–Condon factors(FCFs), and the corresponding radiative lifetimes of the selected transitions from excited ? states to the ground state X~2Σ + 1/2 have been reported. The computed radiative lifetimes τν of low-lying excites ? states are all on the order of 10 ns. Finally, the feasibility of laser cooling of Mg Cl molecule has been analyzed.     

MRCI+Q study of the low-lying electronic states of CdF including spin-orbit coupling

Cd F molecule, which plays an important role in a great variety of research fields, has long been subject to numerous researchers. Due to the unstable nature and heavy atom Cd containing in the Cd F molecule, electronic states of the molecule have not been well studied. In this paper, high accurate ab initio calculations on the Cd F molecule have been performed at the multi-reference configuration interaction level including Davidson correction(MRCI + Q). Adiabatic potential energy curves(PECs) of the 14 low-lying Λ–S states correlating with the two lowest dissociation limits Cd(~1S_g) + F(~2P_u) and Cd(~3P_u) + F(~2P_u) have been constructed. For the bound Λ–S and ? states, the dominant electronic configurations and spectroscopic constants are obtained,and the calculated spectroscopic constants of bound states are consistent with previous experimental results. The dipole moments(DMs) of 2 Σ+ and 2Π are determined, and the spin–orbit(SO) matrix elements between each pair of X2Σ+, 22Σ+, 12Π, and 22Π are obtained. The results indicate that the sudden changes of DMs and SO matrix elements arise from the variation of the electronic configurations around the avoided crossing region. Moreover,the Franck–Condon factors(FCFs), the transition dipole moments(TDMs), and radiative lifetimes of low-lying states-the ground state X2Σ+are determined. Finally, the transitional properties of 22Π–X2Σ+and 22Σ+–X2Σ+are studied. Based on our computed spectroscopic information of Cd F, the feasibility and challenge for laser cooling of Cd F molecule are discussed.     

稀土-六氰合铁氰根桥联配合物的晶体结构和磁化学

以N,N'-二甲基乙酰胺为杂化配体,合成了稀土-铁氰根桥联配合物,测定了其中三个配合物的晶体结构和磁学性质,([SmFe)~n,Gd~2Fe,HoFe)。结果发现在相同的反应条件的一个系列中,呈现三种截然不同的晶体结构,分别为一维链状结构,三核结构和双核结构。同时发现这些配合物具有优良的磁化学性质,特别是[SmFe]~n呈现长程磁有序,临界温度(T~c=3.5K)和较大的矫顽力(H~c=1400Oe)。     

条形靶激光等离子体复合特性的理论研究

报导一个条形靶激光等离子体的计算程序JLULP1,并首次用此程序研究了条形Si靶激光等离子体的空间和时间分布特性及其与靶形状之间的关系.结果表明,条形靶产生的激光等离子体比圆柱形靶产生的激光等离子体更有利于三体复合.     

原子间(锂-锂,氟-氟)位能曲线的ab initio计算

使用先进的量子化学ab initio程序MONSTERGAUSS和各种基函数组,在较大的核间距内计算了锂-锂,氟-氟原子间的位能曲线。并采用组态相互作用(CI)方法计算了基态锂分子(Li₂ ¹∑_g⁺)和基态氟分子(F₂ ¹∑_g⁺)的平衡核间距及总能量。计算结果与其它理论和实验结果进行了比较。     

类Ni离子n=4激发能级通过类Cu离子内壳层电子碰撞电离布居的反应速率系数

在库仑-玻恩交换近似下,使用由我们改善了的Sampson近似,调用Grant等的多组态狄拉克-福克(MCDF)程序包,计算了元素Ho(Z=67)的类Cu离子内壳层电子碰撞电离产生的类Ni离子激发能级布居的反应速率系数。本文结果,将比用原来Sampson等的方法计算所得结果降低25％左右。     

含内环化A—Bb,Cc缩聚反应的溶胶—凝胶分配

结合Ａａ－Ｂｂ，Ｃｃ型缩聚反应，给出了溶胶中含内环化的溶胶－凝胶分配公式及凝胶化条件。     

金刚石(111)面上乙炔生长金刚石薄膜的机理

运用量子力学半经验分子轨道ＡＭ１方法，计算乙炔作为生长基在金刚石（１１１）附氢表面上存在核结构时的外延生长过程，结果表明，乙炔是金刚石（１１１）表面外延生长的有效生长基之一。     

新型希土4-羟基-7-三氟甲基-3-喹啉基甲酸乙酯配合物的光物理性质

首次合成了五种新型希土(Eu³⁺, Tb³⁺, Gd³⁺, Sm³⁺, Dy³⁺)配合物。配体为带有喹啉环的4-羟基-7-三氟甲基-3-喹啉基甲酸乙酯。并用元素分析、红外光谱和热分析方法确定了配合物的组成。通过测定钆配合物的低温磷光光谱表明4-羟基-7-三氟甲基-3-喹啉基甲酸乙酯的三重态能级为22000 cm^-1。配合物的光物理性质表明配体的三重态能级适于希土Eu³⁺, Sm³⁺, Dy³⁺和Tb³⁺，特别是Tb³⁺的发光。     

Spectroscopic properties and radiative lifetimes of SiTe:A high-level multireference configuration interaction investigation

The 18 A-S states correlated to the lowest dissociation limit of SiTe were calculated by using a high-level multirefer-ence configuration interaction （MRCI） method, including scalar relativistic and spin-orbit coupling effects. Based on the calculated potential energy curves, the spectroscopic constants of bound states were determined, which are well consistent with previous experimental results. The spin-orbit matrix elements between the A-S states were computed, which lead to an in-deoth understanding, of oerturbations on the electronic state a^3∏. Finally. the transition dioole moments of allowed transitionsA^1∏-X^1∑^＋,E^1∑^＋-X^1∑^＋,a^3∏-d^3△,a^3∏-d^3△,a^∏-a′^3∑^＋,a^3∏-e^3∑^-,and the radiative lifetimes of A^1∏,E^1∑^＋,and a^3∏ were evaluated.