Abstract: Study on Charge Localization in C_(12)H_8~(2+)Doubly Charged Ion with MNDO MethodQiu Fenghe Liu Shuying (Changchun Institute of Applied Chemistry,Chinese Academy of Sciences, Changchun 130022, China)Received 1993-05-12Abstract:9 possible structures of C12 H82+ doubly charged ion produced from Biphenyl derivatives under 70 eV electron impact were studied by using MNDO semi-empirical quantum chemistry method in the present work. The charge localization and its affection on the stability of the ion were discussed. A two-step mechanism was put forth to illustrate the formation of the ion from Biphenyl derivatives based on the caculation results.Keywords: MNDO, C_(12)H_8~(2+), charge localization