Tree optimized geometries of the mixed system of TATB (1,23,5,- triamino -2,4,6-trinitrobenzene) +CH~2F~2 are gained using the density functional thory (DFT) at B3LYP/3－21G* level. The binding energy, which is corrted for the basis set supersition error by the Boys =Bernardi method, is given. At B3LYP/6----311G*//B3L YP/3---21G*level, the greatest binding energy of TATB and CH~2F~2 is 4.62kJ·mol^-1. In additio, the MO-PM3 method is employed to investigate the intermolecular interactions between TATB and ---（ CF~2CH~2--）-(N=1, 2,3,4,5,)( the end atoms are H) .The binding energies of TATB and －（ CF~2CH~2）--~n are obtained with the approximation of electronic correlation correction by the dispersion energy. The greatest binding energy between －（CF~2CH~2）--~n (n=5) and TATB is 52.97kJ·MOL^-1. The natural bond orbital analysis is used to discuss the charge transfer between TATB and VH~2F~2.

Key words: NITROBENZENE P, DIFLUOROMETHANE, INTERACTIONS, CHARGE TRANSFER