Electronic structure and physical properties of M_iX_i clusters (M = B, Al; X = N, P; i = 1, 2, 3): Ab initio study

Abstract

Ab initio calculations of structural stability and properties of selected IIIa-Va monomers (BN, BP, AlN, AlP), and dimers and trimers thereof are presented. It was demonstrated that multireference methods are needed for an appropriate description of the electronic structure of the diatomics under study. The energy differences between the quasi-degenerated states of monomers were determined: in the range of 220-257 cm(-1) for the X3Pi --> A1Sigma+ in BN, 277-311 cm(-1) for the X3Pi --> A3Sigma(-) in AlN, and 344-768 cm(-1) for the X3Sigma(-) --> A3Pi in the AlP molecule. Many stable isomers of dimers and trimers were optimized and the structural patterns of the species were established. Although the (BN)(i) isomers prefer linear and cyclic geometries with a metal-nonmetal sequence, the structure of the (AlN)(i) species is determined by strong N--N interactions; the geometric patterns of the (BP)(i) and (AlP)(i) systems are more involved. The electronic structure and physical and chemical properties of the most stable dimers and trimers were calculated. As to electronic spectra, absorption bands in the visible and infrared region were found. The calculated low-lying excited states, electron distribution and partially biradical character of structures along with the variety of stable isomers indicate high chemical reactivity of the studied IIIa-Va microclusters.

Geometry, stability, and isomerization of B n N2 (n = 1−6) isomers

“…The potential energy surface (PES) of NB 6 – suggested that the planar hexacoordinate nitrogen species NB 6 – is not stable . The structure and property of (BN) n ( n = 2−11) have been investigated theoretically,[] among which researchers found the stability of cyclic B 3 N 3 isomer with D 3h symmetry is ascribed mainly to its aromaticity . The structure and stability of (BN) n ( n = 2–4) were investigated by ab initio calculations.…”

DFT analysis of the mechanism for the gas-phase chlorination of methane in the HOCL–H2O system

“…Then, the TSR mechanism can provide a pathway with low activation energy or alter the product composition and yield ratio. Oncák et al [12] studied the hydroxylation of alkanes by reagents HOF and HOCl in the gas phase upon acid catalysis but only singlet pathways were investigated (without considering TSR).…”