Calculation of the Energy of Excited States with Zero Electron Orbital Angular Momenta

Russian Physics Journal - Within the framework of the variational method, as the result of a numerical calculation we have found the energy of the excited state and the screening constant of the...     

Parameterized Effective Potential for Excited States and Its Application to the Calculation of Transition Dipole Moments

Optics and Spectroscopy - A parameterized effective potential method that was proposed earlier for the ground state has been developed for excited states with symmetry of the ground state. Various...     

结合n模式表示势的含时密度矩阵重正化群求解激发态非辐射衰减速率：理论形式和在薁分子中的应用

本文提出一种来计算多原子分子包含Franck-Condon区势能面非谐效应的无辐射衰减速率的方法. 这种方法结合了n模式表示法,通过构造第一性势能面和近乎精确的含时密度矩阵重正化群法(TD-DMRG),来模拟量子动力学过程. 另外,在TD-DMRG 的框架下,进一步发展了计算末态分辨的速率常数的算法,它对于分析每个振动模式对于跃迁过程的贡献十分有用. 本文采用这种方法研究了考虑基态势能面非谐性后的薁分子的内转换过程. 结果表明,即使对这个半刚性的分子,模式内的非谐性也能够显著的提高内转换速率;在考虑双模式的耦合之后,速率会进一步增加. 其原因是由于C-H振动的黄昆因子接近于0,其在简谐势能面上无法对内转换做出贡献,而非谐性打开了C-H振动接受电子能量的能力.     

Analytic Perturbation Theory for Bound States in the Transfer Matrix Spectrum of Weakly Correlated Lattice Ferromagnetic Spin Systems

We consider general d-dimensional lattice ferromagnetic spin systems with nearest neighbor interactions in the high temperature region (β≪1). Each model is characterized by a single site apriori spin distribution taken to be even. We also take the parameter α=〈s ⁴〉−3〈s ²〉²>0, i.e. in the region which we call Gaussian subjugation, where 〈s ^k 〉 denotes the kth moment of the apriori distribution. Associated with the model is a lattice quantum field theory known to contain a particle of asymptotic mass −lnβ and a bound state below the two-particle threshold. We develop a β analytic perturbation theory for the binding energy of this bound state. As a key ingredient in obtaining our result we show that the Fourier transform of the two-point function is a meromorphic function, with a simple pole, in a suitable complex spectral parameter and the coefficients of its Laurent expansion are analytic in β.     

Energy Shift of the 4f 136s 1 Excited States of Yb2+ from Gas Phase to the CsCaBr3 Solid

ABSTRACT

Ab initio calculations on Yb²⁺-doped CsCaBr₃ show a large increase (20000 cm^?1) of the 4f ¹⁴ → 4f ¹³6s ¹ transitions from gas phase to CsCaBr₃, due to large embedding effects originated beyond the first bromide coordination shell. The 4f ¹³6s ¹ states of (YbBr₆)^4- in vacuo undergo a sudden energy and electron density change at short Br-Yb distances resulting in the formation of an Yb-trapped exciton, which evolves to full ionization, making Yb(II) unstable in hexabromide coordination in gas phase. Embedding in CsCaBr₃ localizes the 6s electron inside the Br₆ cage, which increases the 6s-Br₆ repulsion and increases the energy of the 4f ¹³6s ¹ states.     

On the Choice of the Wavefunction of the Ground State of He for Precision Calculations of Autoionization State Parameters above the Excited Ion Formation Threshold

The necessity of choosing multiparametric wavefunctions for describing the ground state of an atom in the problems of ionization of atoms by photons and electrons has been substantiated for the He atom as an example. Comparative analysis of application of different ground-state wavefunctions for this atom has been performed. The energies, widths, and partial widths of the lower autoionization state ¹P of the He atom above the excited ion formation threshold has been performed. It is shown that in contrast to total widths of quasi-stationary states, which differ insignificantly for different wavefunctions of the ground state, the partial widths are substantially different.     

产生于能量积聚效应的钠原子高激发态碰撞转移速率的功率效应

报道了用连续单模激光器将Na原子共振激发至3P态,观察到通过Na(3P)-Na(3P)能量积聚碰撞过程布居的高激发态荧光随激发光功率的变化关系。根据碰撞转移模型运用近似二能级系统下的速率方程对实验结果作了解释,理论分析与实验数据相结合得到了高激发态的碰撞转移速率k4D,k5P,k4P,k5S随激发光功率增长的变化特性。     

Possibilities of Distributive Gaussian sp-Functions for Calculating the Correlation Energy of Molecules in the Ground and Excited States

Optics and Spectroscopy - The possibilities of distributive bases from Gaussian sp-functions for calculating the correlation energy of molecules in the second order (Е(2)) of the...     

Excited State Lactim to Lactam Type Tautomerization Reaction in 5-(4-Fluorophenyl)-2-Hydroxypyridine: Spectroscopic Study and Quantum Chemical Calculation

The photophysical properties of 5-(4-fluorophenyl)-2-hydroxypyridine (FP2HP) have been studied by steady state and time resolved spectroscopy in combination with quantum chemical calculations. The molecule FP2HP exists as lactim and lactam form in the ground state due to small stability difference but does not undergo lactim to lactam isomerisation due to high barrier energy. Whereas in the excited state the lactim form undergoes tautomerization producing red shifted emission of the lactam tautomer along with the local emission of the lactim form. In polar protic solvents, the barrier for lactim-lactam tautomerization rapidly decreases forming the lactam tautomer only. Temperature has pronounced effect on the excited state tautomerization equilibrium and is clearly reflected in the measured equilibrium constant (K _tau ⁰ ) and free energy change (??G⁰). Structural calculations at Hartree Fock and Density Functional Theory levels, calculated stability of the isomers in different solvents using Polarized Continuum Model and the theoretical potential energy surfaces for the ground and excited states along the proton transfer coordinate are reported for the tautomeric equilibrium of FP2HP.     

Saturable Excited State Absorption of Cr~(4 ) : YAG for Q-switching Nd : YAG Laser

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Calculation of Binding Energies of the Ground and Excited States of a Donor in Quantum Wells: A Functional Variational Approach

The calculations of the ground and a few low-lying excited states of impurity in the quantum wells (QW's) are presented by making use of a functional variational approach. A new trial wave function is proposed. It is taken by the product of the exact subband state in the Q W and the state of two-dimensional (2D) hydrogenic-like donor with an effective charge distribution along the z-direction (perpendicular to the well interfaces). The variation of binding energies of the donor states in the QW with the well-width is calculated. The calculated result is compared with that obtained by the earlier variational method. The functional variational approach proposed here has some benefits such as, to bring a great flexibility and to apply to a relatively large species of trial wave functions.     

PuN基态分子势能函数与热力学函数的理论计算

在Pu的相对论有效原子实势近似和N原子 6 - 311G 全电子基函数下 ,用密度泛函B3LYP方法计算得到PuN分子基态X6Σ+ 的结构与势能函数、力常数与光谱数据 .同时计算得到PuN(g)分子在 2 98K时的标准生成热力学函数ΔfH0 、ΔS0 和ΔfG0 ,分别为 - 4 87.2 39kJ/mol、95 .345J/molK和 - 5 15 .6 6 6 1kJ/mol.     

Energy dependence of the total cross section for the reaction of 4He ions with silicon nuclei

Directly measured data on the total cross section for the reaction of projectile ⁴He ions with silicon nuclei at energies below 25 MeV/nucleon are presented. The energy dependence of the parameters of a semimicroscopic potential is determined from the measured values of this cross section. This investigation was performed at the Flerov Laboratory of Nuclear Reactions at the Joint Institute for Nuclear Research (Dubna, Russia) and at the Department of Physics at the University of Jyväskylä (Finland).     

中能质子与4He原子核弹性散射中N-N振幅的相改变

在KMT多重散射理论框架下，应用动量空间一级光学势，基于Franco和Yin关于核子-核子散射振幅的相随动量转移而改变的建议，研究了入射能量为1GeV时的质子-4He弹性散射. 发现这个相改变使得KMT类型的理论计算的微分散射截面和极化本领与实验符合得更好.     

Ba2MgGe2O7:Cr4+晶体中荷移激发态对g因子贡献的研究

文章建立了立方四面体3d2络合物g因子的完全高阶微扰公式.在这个公式中,除了与d-d跃迁光谱(晶场激发态)有关的晶场(CF)机制的贡献(包括近年发展的双旋-轨耦合参量模型)外,与电荷转移光谱(荷移激发态)有关的荷移(CT)机制的贡献也被考虑.将这个公式应用于Ba2MgGe2O7:Cr4 晶体平均g因子的计算,发现理论计算值与实验值很好的一致,同时,荷移机制对g移动△g(=g-2.002 3)的贡献△gCT在符号上与晶场机制的贡献△gCF相反,而在大小上约为晶场机制贡献的38%.因此,在对高价态过渡金属离子络合物的g因子计算时应考虑CF机制和CT机制的贡献.     

Application of the symplectic shell model to the L = 0+ states of 4He

The nature of the low-lying L = 0⁺ states of ⁴He is analyzed in the framework of the symplectic shell model. A generator coordinate method for microscopic calculations is used to diagonalize the Brink and Boecker force, B1, in the space defined by the 0ħω and 4ħω irreps of spatial symmetry [f] = [4] and the 2ħω irrep of symmetry [22]. A mixed Sp(3, R) calculation is also attempted. Results show that the first L^π = 0⁺ excited state is a vibrational excitation of the ground state.     

S2O激发态(C1A'')振动光谱及势能面的一种代数研究

利用代数方法研究了非对称弯曲三原子分子S2O分子处于C1A'电子态的能谱及其稳定构型下的势能面,通过对30条光谱数据的拟和得到的rms误差为2.40 cm-1.结果表明,利用此代数Hamiltonian很好的实现了能级再现,它预测了振动总量子数达到20的全部振动能级,同时我们计算了分子的解离能与力常数.通过与实验值比较证明了这种方法在计算这类分子的有效性.     

Logarithmic Correction for the Susceptibility of the 4-Dimensional Weakly Self-Avoiding Walk: A Renormalisation Group Analysis

We prove that the susceptibility of the continuous-time weakly self-avoiding walk on \({\mathbb{Z}^d}\), in the critical dimension d = 4, has a logarithmic correction to mean-field scaling behaviour as the critical point is approached, with exponent \({\frac{1}{4}}\) for the logarithm. The susceptibility has been well understood previously for dimensions d ≥ 5 using the lace expansion, but the lace expansion does not apply when d = 4. The proof begins by rewriting the walk two-point function as the two-point function of a supersymmetric field theory. The field theory is then analysed via a rigorous renormalisation group method developed in a companion series of papers. By providing a setting where the methods of the companion papers are applied together, the proof also serves as an example of how to assemble the various ingredients of the general renormalisation group method in a coordinated manner.