Collision integrals for N(4S)–N(4S), N(4S)–N(2D), and N(4S)–N(2P) interactions
Zi Ding, Zhi Qin, Linhua Liu
Abstract
Collision integrals for the scattering of nitrogen (N) atoms are essential to model transport properties of air plasmas, which can be highly dependent on the species involved. At high temperatures, N atoms may exist in their excited states. Therefore, collision integrals for N atoms are computed at the temperature range of 500–50 000 K, in which the interactions between the excited [N(2D) and N(2P)] atoms and ground N(4S) atom are considered. The interaction between the excited N(2P) atom and ground N(4S) atom is considered for the first time. A comparison of the collision integrals from our combined-hyperbolic-inverse-power-representation (CHIPR) potential energy function with those obtained using other analytical potential energy functions in the literature is given. The results show that the trend of potential energy curves (PECs) in dissociated asymptotic and short-range regions has an important effect on the collision integrals. These regions are difficult to cover in experiments. Here we seek the state-of-the-art ab initio methods for a theoretical guideline to compute the PECs of N2, which are then modeled by the CHIPR function. PECs of some low-lying states are also refined by available experimental spectroscopic data. Overall, our collision integrals are reliable.