Variational Calculation of the Doubly-Excited States Nsnp of He-Like Ions via the Modified Atomic Orbitals Theory

In this paper, we have declined the formalism of the method of the Modified Atomic Orbital Theory (MAOT) applied to the calculations of energies of doubly excited states 2snp, 3snp, and 4snp Helium-like systems. Then we also applied the variational procedure of the Modified Atomic Orbital Theory to the computations of total energies, excitation energies of doubly-excited states 2snp, 3snp, 4snp types of Helium-like systems. The results obtained in this work are in good agreement with the experimental and theoretical values available.

Error Estimates of Some Numerical Atomic Orbitals in Molecular Simulations

Numerical atomic orbitals have been successfully used in molecular simulations as a basis set,which provides a nature,physical description of the electronic states and is suitable for ■(N)calculations based on the strictly localized property.This paper presents a numerical analysis for some simplified atomic orbitals,with polynomial-type and confined Hydrogen-like radial basis functions respectively.We give some a priori error estimates to understand why numerical atomic orbitals are computationally efficient in electronic structure calculations.

Electron capture and excitation in intermediate-energy He^(2+)–H(1s,2s)collisions

The semiclassical non-perturbative atomic orbital close-coupling approach has been employed to study the electron capture and excitation processes in He^(2+)-H(1s)and He^(2+)-H(2s)collision systems.In order to ensure the accuracy of our calculated cross sections,a large number of high excited states and pseudostates are included in the expansion basis sets which are centered on the target and projectile,respectively.The total and partial charge transfer and excitation cross sections are obtained for a wide-energy domain ranging from 1 keV/amu to 200 keV/amu.The present calculations are also compared with the results from other theoretical methods.These cross section data are useful for the investigation of astrophysics and laboratory plasma.

The Erosion Effect of Kapton Film in a Ground-based Atomic Oxygen Irradiation Simulator

In order to investigate the effect of space environmental factors on spacecraft materials, a ground-based simulation facility for space atomic oxygen（AO） irradiation was developed in our laboratory. Some Kapton film samples were subjected to AO beam generated by this facility. The Kapton films before and after AO exposure were analyzed comparatively using optical microscopy, scanning electronic microscopy, atomic force microscopy, high-precision microbalance, and X-ray photoelectron spectroscopy. The experimental results indicate that the transmittance of Kapton film will be reduced by AO irradiation notably, and its color deepens from pale yellow to brown. Surface roughness of the AO-treated sample is already increased obviously after AO irradiation for 5 hours, and exhibits a flannel-like appearance after 15 hours’ exposure in AO beam. The imide rings and benzene rings in kapton molecule are partially decomposed, and some new bonds form during AO irradiation. The mass loss of kapton film increases linearly with the increase of AO fluence, which is resulted from the formation of volatile products, such as CO, CO2 and NOx. The breakage in structure and degradation in properties of AO-treated Kapton film can be attributed to the integrated effect ofimpaction and oxidization of AO beam. The test results agree well with the space flight experimental data.

Modified Atomic Orbital Calculations of Energy of the(2s^(2)^(1)S)Ground-State,the(2p^(2)^(1)D);(3d^(2)^(1)G)and(4f^(2)^(1)I)Doubly Excited States of Helium Isoelectronic Sequence from H-to Ca^(18+)

We report in this paper the ground-state energy 2s^(2)^(1)S and total energies of doubly excited states 2p^(2)^(1)D,3d^(2)^(1)D,4f^(2)^(1)I of the Helium isoelectronic sequence from H-to Ca^(18+).Calculations are performed using the Modified Atomic Orbital Theory(MAOT)in the framework of a variational procedure.The purpose of this study required a mathematical development of the Hamiltonian applied to Slater-type wave function[1]combining with Hylleraas-type wave function[2].The study leads to analytical expressions which are carried out under special MAXIMA computational program.This first proposed MAOT variational procedure,leads to accurate results in good agreement as well as with available other theoretical results than experimental data.In the present work,a new correlated wave function is presented to express analytically the total energies for the 2s21S ground state and each doubly 2p^(2)^(1)D,3d^(2)^(1)D,4f^(2)^(1)I excited states in the He-like systems.The present accurate data may be a useful guideline for future experimental and theoretical studies in the(nI^(2))systems.

Photoionization Study of the 2s^(2)2p^(2)(^(1)D)ns(^(2)D),2s^(2)2p^(2)(^(1)D)nd(^(2)P),2s^(2)2p^(2)(^(1)D)nd(^(2)S),2s^(2)2p^(2)(^(1)S)nd^(2)D,and 2s^(2)2p^(3)(^(3)P)np(^(2)D)Rydberg Series of O+Ions via the Modified Atomic Orbital Theory

We report in this paper energy positions of the 2P˚_2s^(2)2p^(2)(^(1)D)nd 2P,2P˚_2s^(2)2p^(2)(^(1)D)nd 2S,2P˚_2s^(2)2p^(2)(^(1)D)ns^(2)D,2P˚_2s^(2)2p^(2)(^(1)S)nd ^(2)D,and 2P˚_2s^(2)2p^(3)(^(3)P)np ^(2)D Rydberg series in the photoionization spectra originating from 2P˚metastable state of O+ions.Calculations are performed up to n=30 using the Modified Orbital Atomic Theory(MAOT).The present results are compared to the experimental data of Aguilar which are the only available values.The accurate data presented in this work may be a useful guideline for future experimental and other theoretical studies.

Modified Atomic Orbital Theory of the O+ Ion Originating from 2D0 and 4S0 Metastable States

We report in this paper energy positions of the 2D0_2s22p2(1D)nd(2F);2D0_2s22p2(1D)nd(2D);2D0_2s22p2(1D)nd(2P);2D0_2s22p2(1D)ns(2D);2D0_2s22p3(3D)np(2P);2D0_2s22p3(3D0)np(2F), and 4S0_2s22p3(5S0)np(4P) Rydberg series in the photoionization spectra originating from 2D0 and 4S0 metastable states of O+ ion. Calculations are performed up to n = 20 using the Modified Orbital Atomic Theory (MAOT) [1]. The present results are compared to the experimental data of Aguilar et al. [2] which are the only available values. The accurate data presented in this work may be a useful guideline for future experimental and other theoretical studies.

Revealing the Atomic Site-Dependent g-Factor within a Single Magnetic Molecule

The Lande g-factor of a free atom determines the effective magnetic moment of an electron or atom with both spin and orbital angular momentum,which can be calculated by Lande formula,for a transition metal ion in the crystal field,the spin-orbital interaction can mix the non-zero orbital angular momentum of excited states with the＂pure spin＂ground state,resulting in an effective g-factor.Thus,the ability to probe the fine structure of the g-factor allows us to understand the internal spin properties of a magnetic system,such as the spin-orbital interaction.However,for molecular systems,traditional experimental methods for g-factor measurement,like EPR.

过渡金属表面的成键特性及与几何结构的关联

提出了按第一与第二近邻微环境分类表面原子的方法,根据表面原子与体相原子近邻微环境的差异提出了表面原子轨道成键强度的概念,编写了相应的计算程序.这样,金属表面的化学吸附与催化性能可直观地与表面原子的几何特性相联系.这一方法也有助于建立过渡金属表面与原子簇的化学活性的关联.

Principle for the Working of the Lithium-Ion Battery

The technological advances in Lithium-ion batteries have created many new applications, including electric vehicles. In this short note, we shall explain in simple terms the basic physics why and how it is possible to have high energy capacity in Lithium-ion batteries. However, heating has been a common problem and without appropriate design, they might give fire and explosion as reported.

Dynamics of N^(5+)-H electron capture in Debye plasmas

The electron capture in N^(5+)-H collisions imbedded in a Debye plasma is studied by using the two-center atomic orbital close-coupling method in the energy range from 1 keV/u to 200 keV/u.The atomic orbitals and electron binding energies of atomic states are calculated within the Debye-Huckel approximation of the screened Coulomb potential and used in atomic orbital close-coupling dynamics formalism to calculate the electron capture cross sections.The electron capture cross sections and the charge transfer spectral lines of N^(4+)(1s^(2)nl)for a number of representative screening parameter values are presented and discussed.It is found that the screening of Coulomb interactions affects the entire collision dynamics and the magnitude and energy behavior of state-selective cross sections.The changes in electron binding energies and capture cross sections when the interaction screening varies introduce dramatic changes in the radiation spectrum of N^(4+)(1s^(2)nl)capture states with respect to the unscreened interaction case.

Electron capture in collisions of Li3+ ions with ground and excited states of Li atoms

The electron capture processes in collisions of Li3+ion with Li(1s22s)and Li(1s22p0,1)are investigated by using the two-center atomic orbital close-coupling method in the energy range from 0.1 keV/u to 300 keV/u.The interaction of the active electrons with the target ion is represented by a model potential.The present results for the Li3+–Li(1s22s)system are compared with the available theoretical data and general agreement is obtained for the high collision energies.It is also found that the total and partial electron capture cross sections are sensitive to the initial charge cloud alignment in the low energy region.

Seven New Sesquiterpene Lactones from Eupatorium chinense

Seven new sesquiterpenoids, namely eupatochinilides Ⅰ-Ⅶ （1-7）, together with eight known compounds, euponin （8）, mollisorin A （9）, niveusin B （10）, 8β-（4＇-acetoxy-tiglyloxy）-3β-hydroxy-6Hβ,7Hα-germacra-1（10）E,4E,11（13）-trien-6,12-olide （11）, eupalinifide B （12）, 8β-（4＇-hydroxytigloyloxy）-5-desoxy-8-desacyleuparotin （13）, 3-deacetyeupalinin A （14）, and 15-hydroxyleptocarpin （15）, were isolated from the ethanolic extract of the whole plant of Eupatorium chinense L. Their structures and stereochemistry were established by spectroscopic methods and GIAO based ^13C NMR chemical shift calculations.