Ab initio calculation of [OH−;e+] system with consideration of electron correlation effect

Abstract

Ab initio calculations are made to examine theoretically the possibility of stable existence of [OH−;e+] system. Diffuse functions are added to the conventional 6-31G basis set, considering the wide spread of positron orbital. Moreover, the Mo/ller–Plesset perturbation of the second order is calculated to take the electron correlation into account. These two improvements are found to be very effective for the stable existence of the system. The positron affinity of OH− is computed to be 4.9 eV, and the binding energy of positronium to OH as 0.7 eV which is in good agreement with experimental estimate.