Department of Physics, Anhui normal university, Wuhu 241000, People's Republic of China.
J Chem Phys. 2012 Feb 7;136(5):054302. doi: 10.1063/1.3679869.
A theoretical investigation of the He-CN((2)Σ(+)) complex is presented. We perform ab initio calculations of the interaction potential energy surface and carry out accurate calculations of bound energy levels of the complex including the molecular fine structure. We find the potential has a shallow minimum and supports seven and nine bound levels in complex with (3)He and (4)He, respectively. Based on the potential the quantum scattering calculation is then implemented for elastic and inelastic cross sections of the magnetically trappable low-field-seeking state of CN((2)Σ(+)) in collision with (3)He atom. The cold collision properties and the influence of the external magnetic field as well as the effect of the uncertainty of interaction potential on the collisionally induced Zeeman relaxation are explored and discussed in detail. The ratios of elastic to inelastic cross sections are large over a wide range of collision energy, magnetic field, and scaling factor of the potential, suggesting helium buffer gas loading and cooling of CN in a magnetic trap is a good prospect.
本文对 He-CN((2)Σ(+)) 复合物进行了理论研究。我们进行了相互作用势能面的从头算计算，并对复合物的束缚能级进行了精确计算，包括分子精细结构。我们发现该势能具有一个浅的最小值，并分别支持 (3)He 和 (4)He 复合物中的七个和九个束缚能级。基于该势能，我们对 CN((2)Σ(+)) 在磁场中捕获的低场寻求态与 (3)He 原子的弹性和非弹性散射截面进行了量子散射计算。详细探讨和讨论了冷碰撞特性以及外加磁场的影响，以及相互作用势能的不确定性对碰撞诱导塞曼弛豫的影响。在较宽的碰撞能量、磁场和势能标度因子范围内，弹性与非弹性截面的比值较大，这表明氦缓冲气体加载和磁阱中 CN 的冷却具有良好的前景。
