An ab initio study of the hyperfine structure in the X ² ∏ electronic state of CCCH

Abstract

The ab initio study of the magnetic hyperfine structure in the X 2 II electronic state of CCCH are reported. An extensive configuration interaction approach was used to compute the potential surfaces for the two components of the X 2 II electronic state.The vibronic wave functions were calculated with the help of a variational approach with Renner-Teller effect and spin-orbit coupling. It was found that, due to strong geometry dependence of the hyperfine coupling constraints, vibronic averaging of the corresponding functions was carried out to obtain the values to compare with the results of the measurements.