MRCI study on spectroscopic and molecular properties of B-1 Delta(g), B '(1)Sigma(+)(g), C-1 Pi(g), D-1 Sigma(+)(u), E-1 Sigma(+)(g) and 1(1)Delta(u) electronic states of the C-2 radical

作者：Shi, Deheng^*; Zhang, Xiaoniu; Sun, Jinfeng; Zhu, Zunlue

来源：Molecular Physics, 2011, 109(11): 1453-1465.

DOI：10.1080/00268976.2011.564593

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

The potential energy curves (PECs) of six electronic states (B-1 Delta(g), B'(1)Sigma(+)(g), C-1 Pi(g), D-1 Sigma(+)(u), E-1 Sigma(+)(g) and 1(1)Delta(u)) of the C-2 radical have been investigated 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 correlation-consistent aug-cc-pV6Z basis set for internuclear separations from 0.05 to 2.0 nm. The effects on the spectroscopic parameters (T-e, D-0, D-e, R-e, omega(e), omega(e)x(e), omega(e)y(e), alpha(e), beta(e), gamma(e) and B-e) of the core-valence correlation and relativistic corrections are taken into account. The way to consider the relativistic corrections is to employ the second-order Douglas-Kroll Hamiltonian approximation. The core-valence correlation correction is performed at the cc-pCV5Z basis set. And the relativistic correction is carried out at the level of the cc-pV5Z basis set. In order to obtain reliable PECs, the Davidson modification is also included in the study. These spectroscopic parameters have been compared in detail with those of previous investigations reported in the literature, and excellent agreement has been found between the present results and the available experimental data. The first 20 vibrational states are computed for all these electronic states when the rotational quantum number J equals zero, and the vibrational levels, inertial rotation and centrifugal distortion constants of the B-1 Delta(g) and B'(1)Sigma(+)(g) electronic states are reported when J=0, which are in excellent agreement with the available measurements. Comparison with the available experimental data shows that the present molecular constants are both reliable and accurate.

• 出版日期2011
• 单位河南师范大学