Thermal dependence on structures of muoniated and hydrogenated acetone radicals

Abstract

The on-the-fly ab initio density functional path integral molecular dynamics (PIMD) simulations, which can take account of both nuclear quantum effect and thermal effect, were carried out, to analyze the thermal dependence on the structural distributions of muoniated and hydrogenated acetone radicals. We have found that the nuclear quantum effect strongly influences to the bondlength between the muonium (hydrogen) and oxygen atoms. In contrast, the rotational angle of the muonium around the oxygen-carbon axis comparably depends on both the nuclear quantum effect and thermal effect at the room temperature. Such change of the rotational angular distribution of the muonium can originate the thermal dependence on the hyperfine coupling constant value of the muoniated acetone.