First Principle Calculation Of Electronic Structure And Spectroscopic Parameters Of AlX Dimers

Dimer is the smallest cluster, the studying of electronic structure and spectroscopic parameter for dimer can help to understand the evolvement of cluster and self-organization process of materials. Nowadays, the research of dimer is a focus in cluster science, especially for transition metal-containing dimer. In this paper, we study Al-containing dimers by using Gaussian software package.The spectroscopic parameters (bond length, harmonic vibrational frequency and dissociation energy) were studied by using B3LYP hybrid density functional method. Except the dissociation energy of AlCr, the present results are in good agreement with the available experimental and other theoretical values. The present calculations show that the latter transition metal (except Zn, Cd and Hg) can combine strongly with Al compared with the former transition metal. The present calculations also indicate that it is more reasonable to replace La with Lu in the periodic table.The B3LYP hybrid functional were also used to study AlX~±(X=3d element). The ground state spin multiplicities of all the ions are found to differ from the spin multiplicities of the corresponding neutral parents by one. The dissociation energy of channel AlX~+→X+Al~+ is lower than that of channel AlX~+→Al+X~+. As for the AlX~-, the channel AlX~-→X+Al~- is preferred for X=Sc, Ti, Cr, Mn and Zn, and the channel AlX~-→Al+X~- is favor for X= V, Fe, Co, Ni and Cu.In addition, the spectroscopic parameters of AlX and AlX~±, where X represents alkali atom (from Li to Cs) and alkalin-earth atom (from Be to Ba), were investigated by coupled cluster method. The present results are in agreement with the available experimental and other theoretical data. The ground state symmetry of AlLi, AlNa, AlK, AlRb is ~1∑~+, and AlBe~+, AlMg~+, AlCa~+, AlSr~+ and AlBa~+ lie the same ground state. The ground state of AlLi~-, AlNa~-, AlK~-, AlRb~- and AlCs~- is ~2∏, and is the same as in the isoelectronic neutral Al-alkaline-earth dimers. While the ground state of AlBe~-, AlMg~-, AlCa~-, AlSr~- and AlBa~- is high-spin ~3∑~-.