In this paper, Extended Huckel Molecular Orbital Theory ( EHMO) and Complete Neglect Differential and Overlap Method ( CNDO/ 2) are used to calculate chemical reactivity indices of paraffins and their radicals. 本文采用广义休克尔法(EHMO)与全略微分重叠法(CNDO/2)计算了链烷烃及其自由基的反应活性指标。