Structure and mobility of negative ions in simple fluids

The structure of O/sub 2//sup -/ ions in fluid Ne is calculated in frame of density functional method. It is shown that the qualitative behaviour of the negative ion mobility is tightly coupled with the structure of the complex created around the ion and can be explained as a transition from the mobility of the liquid drop in the gas to the mobility of the void in the liquid strongly disturbed in the vicinity of the void.