Experimental and theoretical Compton profiles of Be, C and Al

The results of Compton profile measurements, Fermi momentum determinations, and theoretical values obtained from a linear combination of Slater-type orbital (STO) for core electrons in beryllium; carbon and aluminium are presented. In addition, a Thomas-Fermi model is used to estimate the contribution of valence electrons to the Compton profile. Measurements were performed using monoenergetic photons of 59.54 keV provided by a low-intensity Am-241 γ-ray source. Scattered photons were detected at 90° from the beam direction using a p-type coaxial high-purity germanium detector (HPGe). The experimental results are in good agreement with theoretical calculations.     

Uniqueness on identification of cubic convolution nonlinearity

We shall consider the inverse scattering problem for time dependent version of Hartree equation and nonlinear Klein-Gordon equation. The uniqueness theorem on identifying the cubic convolution nonlinearity from the knowledge of the scattering operator will be shown.     

A green function approach to shear viscosity coefficient

Modified transport equations are derived from Kadanoff and Baym kinetic equations, suitable for the study of thermal transport coefficients. These equations include the Hartree average energy term which has been ignored in the previous studies of thermal transport coefficients. They are linearised and the successive perturbation method is employed to solve them. The solutions are applied to shear viscosity coefficient of gases and the results are compared with the recent experimental measurements for several complex and simple gases. The potential assumed is a hard core one with a perturbation tail. The agreements are particularly good for gases with low molecular weight and in the high temperature range. For complex molecules even in the low temperature range, the agreement is better than the previous calculations. The formula derived yields the explicit temperature dependence of the viscosity coefficient.     

原子核结构的相对论第一性原理研究

过去几十年中,原子核物理的相对论密度泛函理论得到很大发展,可以成功地描述各种原子核现象。文章阐述在相对论框架下研究原子核多体问题的必要性,介绍原子核物理中相对论密度泛函理论的基本概念,回顾相对论密度泛函理论在描述原子核基态、手征转动和动力学过程等方面的应用,讨论基于原子核物理的相对论第一性原理研究,即完全自洽的相对论Brueckner—Hartree—Fock理论,构建微观普适的密度泛函的基本思想。     

Gaussian basis sets for CO2 molecule generated with the molecular improved generator coordinate Hartree–Fock method

The molecular improved generator coordinate Hartree–Fock (MIGCHF) method is used to generate increasing size atom-centered Gaussian basis sets for the CO₂ molecule. From these basis sets total HF energies and second-order correlation energies were calculated and compared with results obtained with other approaches. Considering our largest basis set, the HF energy is in error by 98 hartree and the second-order correlation energy corresponds to 95.6% of an estimate of the limiting value. The relevance of the present calculations is to show the accuracy that can be achieved in studies of small polyatomic molecules with the MIGCHF method.Acknowledgement We acknowledge the financial support of CNPq (Brazilian Agency). We employed computational facilities at Universidade Federal do Espírito Santo and Universidade Estadual Paulista (IQ Araraquara).     

Semiclassical spectral series of a Hartree-type operator corresponding to a rest point of the classical Hamilton-Ehrenfest system

We consider the classical equations of motion in quantum means, i.e., the Hamilton-Ehrenfest system. In the semiclassical approximation in the framework of the covariant approach based on these equations, we construct the spectral series of a nonlinear Hartree-type operator corresponding to a rest point. __________ Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 150, No. 1, pp. 26–40, January, 2007.     

Performance of the Harris functional for extended basis sets at the Hartree-Fock and density functional levels

The Harris functional is a noniterative variational procedure that uses an input charge density to produce an energy that is surprisingly accurate compared to the converged Kohn-Sham self-consistent result. We adapted and generalized this functional for the Hartree-Fock closed- and open-shell cases as well as examined its use for hybrid density functional methods such as B3LYP. Analysis of extended basis set calculations shows that at the B3LYP level an input density formed from a double zeta + polarization orbital basis is accurate enough to reproduce the energy of triple zeta + double polarization + diffuse orbital basis. For large molecules this translates into a computational speed that can be an order of magnitude faster. In the case of Hartree-Fock calculations a "bootstrapping technique" that employs successive applications of the Harris functional can further reduce computational times while retaining sufficient accuracy.