High-temperature rotation–vibration spectrum of iminosilylene (HNSi)

Abstract

Iminosilylene (HNSi) has been observed in the laboratory and is expected to occur in the envelopes of carbon-rich stars. However, the lack of spectroscopic information for HNSi has hampered its further astrophysical detection. Using robust ab initio methods, we present the first and comprehensive molecular line list for HNSi (X ¹Σ⁺). The new line list contains almost 3.36 billion transitions between 1.57 million levels with rotational excitation up to J = 160. It is suitable for temperatures up to 3000 K and covers the wavenumber range of 0–9000 cm⁻¹ (wavelengths λ > 1.11 μm). This new line list can be helpful for the future spectroscopic characterization and molecular detection of HNSi in the laboratory and interstellar space.