2017MNRAS.471...80S

The HNCO-He complex is characterized using explicitly correlated ab initio methodology. We generate its potential energy surface (PES) along the intermonomer Jacobi coordinates. This PES is incorporated later into dynamical computations in order to deduce the rotational excitation cross-sections and coefficient rates of HNCO colliding with He. Calculations of state-to-state cross-sections for transitions among the first 31 rotational levels of HNCO (up to J_KaK_c = 10₁₉) are performed using the quantum close-coupling scheme for total energies < 100 cm^–1 and using the coupled state approach for energies up to 550 cm^–1. Rate coefficients for temperatures ranging from 2 to 100 K are calculated by the averaging of the cross-sections over a Maxwell-Boltzmann distribution. A propensity rule towards even ΔJ rotational transition is observed. The present theoretical data are needed for the estimation of the abundance of the astrophysical important HNCO molecule from the surveys.