DEPERTURBATION ANALYSIS FOR THE a3_ AND c3__ STATES OF C2

In the last symposium and a recent paperfootnote{W. Chen, K. Kawaguchi, P. F. Bernath, and J. Tang, J. Chem. Phys. 142, 064317 (2015).}, we reported a simultaneous analysis for the Phillips and Ballik-Ramsay band systems with a deperturbation treatment for the X$^{1}Sigma^{+}$ and b$^{3}Sigma^{-}$ states of C$_{2}$ and also, for the first time, the observation of the forbidden transitions between the singlet and triplet states of C$_{2}$. In the present study, we consider the interaction between the a$^{3}Pi$ and c$^{3}Sigma^{-}$ states to remove some anomalies in the higher order constants of the a$^{3}Pi$ state presented in the previous work. The local interaction between the a$^{3}Pi$ v=7 and c$^{3}Sigma^{-}$ v=1 states was considered in a recent analysisfootnote{M. Nakajima and Y. Endo, J. Mol. Spectrosc. 302, 9 (2014).} for the perturbation of the spectrum. We consider the interaction between all the vibrational levels of the two electronic states with a set of Dunham-like constants. The progress and results will be presented