Positron-Electron Annihilation Process in（2,2）-Difluoropropane Molecule

The positron-electron annihilation process in（2,2）-difluoropropane molecule and the corresponding gammaray spectra are studied by quantum chemistry method.The positrophilic electrons in（2,2）-difluoropropane molecule are found for the first time.The theoretical predictions show that the outermost 2s electrons of fluoride atoms play an important role in positron-electron annihilation process of（2,2）-difluoropropane.In the present scheme,the correlation coefficient between the theoretical gamma-ray spectra and the experiments can be 99%.The present study gives an alternative annihilation model for positron-electron pair in larger molecules.