Abstract:

The structure of SnO ground state molecule is optimized by employing density functional theory (B3P86) method with SDB-cc-pVTZ basis sets for Sn atom and 6.311++G** for O atom. The effects of electric filed on the bond length, total energy, mulliken atomic charges, the Highest Occupied Molecular Orbital(HOMO) energy level, the Lowest Unoccupied Molecular Orbital(LUMO) energy level, energy gap, electric dipole moment, harmonic frequency and infrared intensity of SnO ground state molecule are studied. The excited properties of SnO molecule under different electric fields are also investigated by using configuration interaction singles density functional theory (CIS-B3P86) method. The results show that the bond length and electric dipole moment are found to firstly decrease, then increasing with increasing of positive direction electric fields, the minimums are 0.1796nm at F=0.04a.u. and 0.2124 Debye at F=0.03a.u., respectively. The total energy is proved to firstly increase, then decreasing with increasing of positive direction electric fields, the maximum is -2144.8396eV at F=0.03a.u.. The EH and harmonic frequency are found to increase with increasing of positive direction electric fields, but the EL, Eg and infrared intensity are decreasing. The magnitude and direction of the external electric field have important effects on excitation energies, oscillator strengths and the wavelength.

Key words: SnO, external electric field, excited properties