Improving the Accuracy of HCN/HNC Opacity Data and Accounting for Isotopomers

Abstract

The HCN/HNC linelist of Harris et al. ApJ, 578, 657, (2002), is the most accurate and extensive ab initio linelist in existence. However it suffers from the inherent accuracy problems of ab initio data. The band centres of some overtone bands deviate by up to 10 cm(-1) from experimental values. To improve the quality of many of our line frequencies we are in the process of substituting the available experimentally determined HCN energy levels for their ab initio counterparts. Thus improving the accuracy of many of the strongest HCN/HNC line frequencies. We propose to generate an approximate (HCN)-C-13 linelist using experimentally determined energy levels of (HCN)-C-13 with our HCN line intensities. Our preliminary results are presented here.