Theoretical Prediction of a 443 Nm Transition: a Potential Carrier of a Diffuse Interstellar Band

The carriers of the diffuse interstellar bands (DIBs) is one of the longest standing problems in astronomical spectroscopy. This completely unattributed absorption spectrum stretches from the UV to near-IR and can be seen in multiple interstellar sightlines with the strongest features at 443 nm and 578 nm. Additionally, the number of known features grows with every observation. No known molecular spectra have been matched to the DIBs as observed in the interstellar medium. It has been hypothesized that the molecular carriers of the DIBs may play a role in many aspects of astrochemistry including the potential for better understanding of the origins of the chemical building blocks of life. The current approach to answering the problem of the carriers of the DIBs, a form of experimental guess and test, has yet to prove fruitful. The use of chemical theory and computation in answering this problem seems promising, but has been held up by development of the necessary computing capabilities. With state-of-the-art computational techniques we have examined several proposed carriers of the DIBs. In this work, we report on our findings including a molecule that our methods predict to have a strong transition at 442 nm.