Experimental energy levels of 12C14N through MARVEL analysis

TL;DR

This paper empirically determines accurate rovibronic energy levels for the CN molecule using the MARVEL algorithm, significantly improving the accuracy of transition frequencies and enhancing molecular data for astronomical and chemical applications.

Contribution

It provides the first comprehensive empirical energy levels for 8 doublet states of CN, validated from multiple sources, and updates the existing line list with these precise measurements.

Findings

Transition frequencies are now 77.3% experimentally validated, up from 11.3%.

92.6% of high-intensity transitions are experimentally supported.

Complete partition function recovery at 2000 K using MARVEL energy levels.

Abstract

The cyano radical (CN) is a key molecule across many different factions of astronomy and chemistry. Accurate, empirical rovibronic energy levels with uncertainties are determined for 8 doublet states of CN using the \Marvel{} (Measured Active Rotational-Vibrational Energy Levels) algorithm. \notrans{} transitions were validated from \nosources{} different published sources to generate \noenergy{} spin-rovibronic energy levels. The empirical energy levels obtained from the \Marvel{} analysis are compared to current energy levels from the \Mollist{} line list. The \Mollist{} transition frequencies are updated with \Marvel{} energy level data which brings the frequencies obtained through experimental data up to \alert{77.3\%} from the original 11.3\%, with 92.6\% of the transitions with intensities over 10$^{-23}$ cm/molecule at 1000 K now known from experimental data. At 2000 K, 100.0\% of the partition function is recovered using only \Marvel{} energy levels, while 98.2\% is still recovered at 5000 K.