Dipole Moment and Electronic Structure Calculations of the Electronic States of the Molecule SiC below 97000cm-1

Karam Hamdan,Ghassan Younes,Mahmoud Korek

doi:10.5539/mas.v10n11p192

Abstract

Beside its importance in the astrophysics, the silicon carbide has a great importance in the industry of semiconductors and ceramics. Because of the absence of theoretical data, extensive ab initio calculations of dipole moment and higher excited electronic state have been done for this molecule. These calculations have been performed by using the Complete Active Space Self Consistent Field (CASSCF) with Multireference Configuration Interaction MRCI+Q (singly and doubly excitation with Davidson corrections). The potential energy and the dipole moment curves for the 47 low-lying singlet, triplet and quintet electronic states in the representation 2s+1Λ(+/-) of the molecule SiC have been calculated. The harmonic frequency we, the internuclear distance Re, the electronic energy with respect to the ground state Te, the rotational constants Be and the permanent dipole moment have been obtained for these electronic states. The comparison between the values of the present work and those available in the literature, for several electronic states, shows a good agreement. In the present work thirteen new electronic states have been investigated here for the first time. These new results may leads to more investigation of new experimental works on this molecule.

Highlights

Since the SiC is an elusive molecule, its experimental detection is extremely difficult in a high temperature in thermodynamic equilibrium
From the electronic transition C3Π-X3Π, the spectroscopic constants of these electronic states have been measured by Butenhoff et al (Butenhoff et al, 1991)
The spectroscopic properties for the three lowest lying electronic states X3Π, A3Σ- and a1Σ+ of the diatomic SiC molecule have been computed based on an augmented coupled cluster and different basis sets methods by (Martin, Francois, & Gijbels, 1990)

Summary

Introduction

Since the SiC is an elusive molecule, its experimental detection is extremely difficult in a high temperature in thermodynamic equilibrium This problem can be solved by sputtering the SiC in a hollow discharge lamp. The absence of theoretical dipole moment calculation and the electronic structure investigation for higher excited electronic states (up to 97000cm-1) of the silicon carbide molecule SiC stimulates us to investigate, in the present work, more extensive ab initio calculation for this molecule. These theoretical calculations, in the present-days, are quite capable of producing, with high accuracy, the required data if they are judiciously applied. Vol 10, No 11; 2016 dipoles moments and the transition lines intensities the permanent dipole moment have been calculated for the considered electronic states of this molecule

Method

Results

Permanent Dipole Moment

Conclusion