Positron annihilation is widely applied to study the material structure. The positron annihilation research group in Nuclear physics and Nuclear engineering Dept. is developing an theoretical approximation model of positron annihilating in material. This model is based on DFT - Density Functional Theory and VQMC – Variational Quantum Monte Carlo method which is performed to get the pseudo ground state of positron binding to atom or molecule in material. This is a many-particle system which is reduced to single particle system by Kohn – Sham approximation. In this model, the many particle interactions are included in the correlation function – Jastrow function. The model has been carrying out to materials such as ZnO, CuO, and TiO2.
