Ab initio Calculation for Positronic Compounds

Abstract

We have developed quantum multi-component ab initio methods, such as multi-component molecular orbital and multi-component quantum Monte Calro methods, for theoretical calculation of positronic compounds. We have carried out the accurate calculation of positron affinity (PA) and pair annihilation rate for positronic compounds by using these multi-component methods, and found that these values are in reasonable agreement with the corresponding experimental ones. We found that (i) the positronic orbital is much more delocalized than the electronic highest occupied molecular orbital, and (ii) there exist the strong correlation between PA and dipole moment.