The matrix elements of the correlation function between symmetric potential harmonics are simplified into the analytical summations of the grand angular momenta by smartly using the recurrence and coupling relations of the potential harmonics. The correlation-function potential-harmonic and generalized-Laguerre-function method (CFPHGLF) , recently developed by us, is applied to the S states of the helium-like systems for Z = 2 to 9. The results exhibit good convergence with the bases in terms of both the angular and radial directions. The final eigen-energies agree excellently with the best s-limits of the variational configuration interaction (CI) method for the involved low-lying S states. The accuracy of the potential harmonic (PH) expansion scheme is discussed relative to the exact Hylleraas CI results (HCI), and Hartree-Fock results. Moreover, suggestion is given for the future improvement of the PH scheme.
The geometries of imidazole and its derivatives were respectively optimized by using ab initio method, and the molecular orbital energy levels and the charge densities were obtained for their optimum geometries. The frontier orbital energy levels, and the net charges of N (1) atom and the imidazole ring of those molecules were obtained with ab initio and SCC-DV-Xα methods. It was found that the inhibition properties of those compounds change with the highest occupied molecular orbital energy levels, and the net charges of N(1) atom. We took four iron atoms on the crystal plane (100) of α-iron as the surface which was used to study the adsorption towards the inhibitors. The adsorption models of the inhibitor to be adsorbed on the Fe-cluster surface were optimized with SCC-DV-Xα method. It turns out that the most favorable model is that the inhibitor molecule is adsorbed on the Fe-cluster surface in an inclined state. The calculation shows that the stabilization energies of the systems are well correlated with the inhibition efficien cies.
YAN Xiao-ciXIA Wen-bingLIU JieOU YANG-liLUO Ming-daoYANG FengMIN Xin-min
We proposed a simple potential harmonic(PH) scheme for calculating the non\|relativistic radial correlation energies of atomic systems. The scheme was applied to the low\|lying \%n\%\+1\%S\%(\%n\%=1,2) and \%n\%\+3\%S\%(\%n\%=2,3) states of the helium atom. The results exhibit a very stable convergence characterization in both the angular and radial directions with PH and generalized Laguerre functions(GLF) respectively, even though the method is non\|variational one. The ninth significant figure of the non\|relativistic radial energy(NRE) calculated for the ground state exactly agrees with that of the most accurate literature data from the modified configuration interaction method. The convergent NRE′s for the excited states 2\+1\%S\%, 2\+3\%S\% and 3\+3\%S\% with the similar accuracy were also obtained.
WANG Yi\|xuan, BU Yu\|xiang and LIU Cheng\|bu\+\{**\} (Faculty of Chemistry, Shandong University, Jinan 250100, P. R. China)
Recently some new apparatuses have been developed to study the thermal decomposition and the photodecomposition mechanism of silver azide with some new experimental results. We anal- ysed the experimental results with ab initio calculations (CASSCF, valence CI, MC-CEPA, ACPF and CEPA), assigned the spectrum structure of AgN3, plotted the potential energy curves of AgN3 and reinterpreted the photodecomposition mechanism of silver azide. The poten- tial energy curves of the two lowest singlet and the two lowest triplet valence states of AgN3 a- long AgN-NN distance R2 show that the two singlet valence states are involved in the photodisso- ciation of AgN3, proved by the two peaks at 2. 18 and 2. 23 eV which are the results of the elec- tron transition from the ground state to the two singlet valence states respectively.
SHI Shou-heng, SHI Chuan, Zhang Shao-yin and Dai Hong-yi (Dalian College of Light Industry, Dalian 116034, P. R. China)
The wave functions of the n1,3p (n=2, 3, 4) and the n 1,3D (n=3, 4, 5 ) low-lying states of the helium atom are expanded into the complete sets of the symmetrically adapted basis functions from hyperspherical harmonic functions in the angle part and of generalized Laguerre functions in the radial part respectively, and are then augmented by the simplest type of Jastrow correlation factor to incorporate electron-nucleus cusp only. The excellent agreement between the present nonrelativistic eigen-energies and those from the sophisticated configuration interaction (CI) method for the examined states indicates that the hyperspherical harmonic method can also be applied to the P and the D excited states of the helium atom.
WANG Yi-xuan, ZHUANG Bing-you and LIU Cheng-bu (School of Chemistry, Shandong University, Jinan 250100, China) (Department of Chemistry, Weifang College, Weifang 261043, China)
