Open AccessA study on spectroscopic parameters of X2+, A2 and B2+ low-lying electronic states of SiN radical
Author(s) -
Jiemin Wang,
H. Q. Feng,
Jinfeng Sun,
Deheng Shi,
Wentao Li,
Zunlue Zhu
Publication year - 2013
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.62.013105
Subject(s) - valence (chemistry) , basis set , multireference configuration interaction , complete active space , atomic physics , hamiltonian (control theory) , physics , configuration interaction , potential energy , quantum mechanics , mathematics , molecule , excited state , mathematical optimization
The potential energy curves (PECs) of X2+, A2 and B2+ low-lying electronic states of SiN radical are investigated using the highly accurate valence internally contracted multireference configuration interaction (MRCI) approach combining the full valence complete active space self-consistent field method. In the present calculations, the basis sets used are correlation-consistent basis sets, aug-cc-pV6Z. The PECs determined by the MRCI calculations are corrected for size-extensivity errors by means of the Davidson modification (MRCI +Q). To obtain more reliable results, effects of the core-valence correlation and relativistic correction on the PECs are taken into account. The core-valence correlation correction is carried out with the cc-pCV5Z basis set The way to consider the relativistic correction is to use the second-order Douglas-Kroll Hamiltonian approximation, and the correction is performed at the level of cc-pV5Z basis set. With these PECs, the spectroscopic parameters are determined. A comparison with the experimental data shows that the present spectroscopic parameters are more accurate than the previous calculations.