Isotope shifts of the 1s22s2(1S0)→1s22 p2(1S0) transition in the doubly ionized carbon ion C2+

Abstract

Highly accurate quantum mechanical calculations are performed for the 1s22s2 (1S0)→1s22p2 (1S0) transition energy in the isotopomers of C2+ ion to determine the isotope shifts. Explicitly correlated Gaussian functions and a variational approach that explicitly includes the nuclear motion are employed in the calculations. The leading relativistic and quantum electrodynamics corrections to the transition energy are also calculated using the perturbation theory with the nonrelativistic wave function as the zero-order approximation. It is determined that the 12C2+ transitions energy, which is obtained from the calculations to be 182 519.031 cm−1 (vs the experimental value of 182 519.88 cm−1, an excellent sub-wave-number agreement) up-shifts by 1.755 cm−1 for 13C2+ and by additional 1.498 cm−1 for 14C2+. Those shifts are sufficiently large to be measured experimentally