Separation of electronic states for small molecular ions by the mobility measurements in cooled He gas

Abstract

Synopsis In some cases of the ion mobility measurements in cooled He gas, we have observed the separation of electronic states for small molecular ions. Both NH+ and ND+ show the separation of X2Π and a4Σ states. The meta-stable ND 2 + and NH 3 + were observed, but these of NH 2 + and ND 3 + do not appear in the measurements. The reason of the isotope dependence in mobility measurement is discussed using the calculated potential energy curves for NH 2 + and ND 2 + .