Chen Hong-shan

Structures and electronic properties of SimN8-m(0 < m < 8) clusters: a density functional theory study

The geometries, electronic structures and related properties of SimN8-m(0 < m < 8) clusters are studied using density functional theory (DFT) with hybrid functional B3LYP. The calculated results reveal several trends. For any stoichiometric clusters, the lowest energy isomers with an alteration of N and Si atoms are favourable in energy if the numbers of Si and N atoms are large enough to form ... Si–N–Si–N... alternative chains. The bond lengths of single Si–N bonds are very close to the corresponding values of the bulk and other Si–N clusters. The geometries for N-rich and Si4N4 clusters are planar structures, but three-dimensional structures are favourable in energy for Si-rich clusters. With the increase of m, the isotropic polarizability and average polarizability increase, the total binding energies generally decrease, the HOMO-LUMO gap and vertical ionization potential oscillate with increasing number of valence electrons, and their values with even valence electrons are larger than those with odd valence electrons. The atomic charges, IR and Raman properties are also reported.

DFT study on the structure and spectra of Ga5P5 cluster

In this paper, possible structures of Ga5P5 cluster were optimized by using density functional method with generalized gradient correction (B3LYP). The electronic structure of the isomers with lower energy was studied. The most stable structure obtained for Ga5P5 is a distorted pentaprism. The Ga-P bond formed in the cluster is strongly ionic. Based on NBO analysis, an average value of 0.59 electron transfers from Gallium to Phosphorus. The bond length 2.33–2.43 A is around the value in bulk GaP. The HOMO-LUMO gap is about 2.2 eV. The dipole moment and polarizability are calculated, and the IR and Raman spectra are also presented.

STRONG LOCAL CONFIGURATION INTERACTIONS AND THEIR INFLUENCE ON THE LEVEL STRUCTURE AND TRANSITIONS OF 2s2p63l CONFIGURATIONS IN AlIV–MnXVI

Abstract ab initio multiconfiguration interaction method HXR with relativistic corrections was used to calculate the energy levels and oscillator strengths of Ne-like ions AlIV–MnXVI. Strong local configuration interactions between 2s2p 6 3 l and 2s 2 2p 5 nl exist in these ions. Their effect on the level structure and transition oscillator strengths was analyzed. The wavelengths and weighted oscillator strengthens of 2s2p 6 3d–2s2p 6 3p, 2s2p 6 3p–2s2p 6 3s transitions were listed.