共查询到18条相似文献,搜索用时 703 毫秒
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在改进的Hartree-Fock-Slater原子模型的基础上,在中心场近似下用含能带效应的全动态电子判据处理自由电子与束缚电子的密度分布,提高了电子波函数、电子占据数等原子参数的计算精度.通过平均近似处理,给出了劈裂的能带,从而改善了物质电子状态方程的计算精度.结果部分详细计算了W元素的原子能量、电子压强、熵、定容热容及其它热力学参数 相似文献
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在改进的平均原子模型的基础上,在中心场近似下用分波法来处理部分自由电子密度分布函数,提高了电子波函数、电子占据数等原子参数的计算精度.通过平均近似处理,给出了劈裂的能带.通过使用分波法来准确计算贵金属Au的电子状态方程. 相似文献
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在改进的平均原子模型的基础上,在中心场近似下用分波法来处理部分自由电子密度分布函数,提高了电子波函数、电子占据数等原子参数的计算精度.通过平均近似处理,给出了劈裂的能带.通过使用分波法来准确计算贵金属Au的电子状态方程. 相似文献
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通过广义梯度近似的第一原理全电子相对论计算, 研究了不同界面类型InAs/GaSb超晶格的界面结构、电子和光吸收特性. 由于四原子界面的复杂性和低对称性, 通过对InAs/GaSb超晶格进行电子总能量和应力最小化来确定弛豫界面的结构参数. 计算了InSb, GaAs型界面和非特殊界面(二者交替)超晶格的能带结构和光吸收谱, 考察了超晶格界面层原子发生弛豫的影响.为了证实能带结构的计算结果, 用局域密度近似和Hartree-Fock泛函的平面波方法进行了计算. 对不同界面类型InAs/GaSb超晶格的能带结构计算结果进行了比较, 发现界面Sb原子的化学键和离子性对InAs/GaSb超晶格的界面结构、 能带结构和光学特性起着至关重要的作用. 相似文献
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为得到由中、高Z元素形成的非局域热动平衡等离子体中的离子丰度分布的可靠信息 ,对建立速率方程所需的各种离子的各个原子过程采用了基于一级微扰论的计算 ,提高了原子参数的精度 ;为了进一步节省计算时间 ,在保证精度的前提下 ,针对不同的过程做了不同的近似处理 ;对各个原子过程的计算结果进行多方比较,表明精度可靠. 相似文献
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Dipole-allowed single photoionization of some closed shell atoms and ions has been investigated in the relativistic random-phase
approximation (RRPA). Application of relativisticmultichannel quantum defect theory (RMQDT) is made together with RRPA to
analyse autoionizing resonances. Analysis points to the importance of interchannel coupling in high energy photoionization
and reveals various degeneracies in relativistic atomic spectra to influence the low energy dynamics. Interesting threshold
behavior in photoelectron spin polarization has been seen. Prospective future studies have been indicated. 相似文献
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在有心力场近似和组态相互作用理论框架下,通过对电子波函数、各个壳层上电子的束缚能、平均轨道半径、总束缚能、基组态时的激发能、电离能的分析和计算,研究了Lr原子的可能基组态及其基组态时的原子态.研究结果表明:基组态为5f147s27p,基态时的原子态为2P1/2. 相似文献
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Summary A theoretical treatment, of first order in the collision dynamics, is presented to analyse the role of electric polarization
in offresonance laser-assisted atomic collisions. General expressions are presented for evaluating the modified spectrum and
wave functions for anyn level of hydrogenic atoms in the presence of a laser, taken to be linearly and circularly polarized. Specific calculations
are carried out for excitation of hydrogen atoms to the leveln=2 by electron impact. The two polarizations are found to yield large differences i) in the atomic-spectrum modifications,
ii) in the structure of the cross-sections and iii) in the numerical results. In particular, only for linear polarization,
the distribution in energy of the scattered electrons at a fixed scattering angle has the structure of a series of equally
spaced lines of different height (the spacing being equal to the laser photon energy ℏw and the height of the line accounting for the number of final electrons with a given energy). For circular polarization no
such a regular pattern is predicted. Since, among laser-assisted particle-atom collisions, at present energy gain-loss spectra
of scattered electrons are most easily observed, it is hoped that the reported results may serve as a stimulus for new observations
in this new class of atomic collisions. The theory to treat the multiphoton resonance case is outlined too.
To speed up publication, the authors of this paper have agreed to not receive the proofs for correction. 相似文献
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Yu. I. Golovin D. V. Lopatin R. K. Nikolaev A. A. Samodurov R. A. Stolyarov 《Physics of the Solid State》2006,48(9):1827-1830
The energy spectrum of local charge-carrier trapping centers in C60 single crystals is studied in terms of the theory of space-charge-limited currents in the Gaussian approximation. The energy distribution of these centers in the energy gap is found, and the type and parameters of this distribution are determined. 相似文献
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D. B. Hayrapetyan E. M. Kazaryan 《Journal of Contemporary Physics (Armenian Academy of Sciences)》2012,47(5):230-235
In the framework of adiabatic approximation the energy spectrum and wave functions of two impenetrable particles in an infinitely deep potential well are considered for two cases of approximation of the effective confining potential of the ??slow?? subsystem. In case of the quadraticterm approximation the obtained energy spectrum is equidistant. The probability distribution in the range of ??fast?? particle has a symmetric shape while that in the range of the ??slow?? particle is asymmetric and the peak of localization of the system in its ground state is shifted towards the ??fast?? particle. In the first excited state the center of the probability distribution of the ??slow?? particle is shifted towards the impenetrable wall. 相似文献
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由“从正则分布出发,在小涨落近似下得出的能量涨落分布公式”求得的能量涨落的二次矩与直接由正则分布求得的二次矩完全相同,但分别由二求得的高次矩并不完全相同。 相似文献
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Abstract Collision cascades in Cu, Au and Cu3Au are generated by full molecular dynamics (MD) and by its binary collision approximation (BCA) with the Marlowe program. Cu and Au primaries have 1 keV initial energy. The same Molière repulsive potential is used in both models for close encounters. In the MD model, this potential is carefully splined to the pair component of the N-body potential developed by Ackland and Vitek. In the BCA, this N-body interaction is roughly modeled by a constant isotropic 4 eV binding energy of the target atoms to their rest positions. Time distributions of the number of atoms moving with a total energy higher than a threshold value E d are compared and discussed. Recoil range distributions during the cascade development are discussed as well. The agreement between MD and BCA is fairly good in all cases for E d larger than about 3 eV. In the case of smaller E d-values, the BCA may result in an overestimate of the number of moving atoms in the late development of the cascades. This discrepancy is suggested to originate in the lack of attractive forces between the moving particles and the surrounding atoms in the BCA. 相似文献