Potential Energy Curves for C2

Potential energy curves for the a 1Σg+, X 3IIu, 3Σg—, b 1IIu, A 3IIg, c 1IIg, B 3IIg, d 1Σu+, and e 1Σg+ states of C2 have been calculated by the Rydberg—Klein—Rees method. These curves have been compared with some of the recent quantum calculations of Clementi and Pitzer on this same system. The recent identification of the ground state as the a 1Σg+ by Ballik and Ramsay and the determination of the dissociation energy by Brewer, Hicks, and Krikorian have been used to calculate tentative values for the dissociation energies of all of the observed excited electronic states.