MRCI study of spectroscopic and molecular properties of X-1 Sigma(+)(g) and A(1)Pi(u) electronic states of the C-2 radical

作者：Zhang Xiao-Niu; Shi De-Heng^*; Sun Jin-Feng; Zhu Zun-Lue

来源：Chinese Physics B, 2011, 20(4): 043105.

DOI：10.1088/1674-1056/20/4/043105

• potential energy curve
• spectroscopic parameter
• molecular constant
• isotope effect

The potential energy curves (PECs) of X-1 Sigma(+)(g) and A(1)Pi(u) electronic states of the C-2 radical have been studied using the full valence complete active space self-consistent field (CASSCF) method followed by the highly accurate valence internally contracted multireference configuration interaction (MRCI) approach in conjunction with the aug-cc-pV6Z basis set for internuclear separations from 0.08 nm to 1.66 nm. With these PECs of the C-2 radical, the spectroscopic parameters of three isotopologues (C-12(2), (CC)-C-12-C-13 and C-13(2)) have been determined. Compared in detail with previous studies reported in the literature, excellent agreement has been found. The complete vibrational levels G(v), inertial rotation constants B, and centrifugal distortion constants D-v for the C-12(2), (CC)-C-12-C-13 and C-13(2) isotopologues have been calculated for the first time for the X-1 Sigma(+)(g) and A(1)Pi(u) electronic states when the rotational quantum number J equals zero. The results are in excellent agreement with previous experimental data in the literature, which shows that the presented molecular constants in this paper are reliable and accurate.

• 出版日期2011-4
• 单位河南师范大学