Two-photon annihilation rate of the positronic HCN molecule

Abstract

Positron binding by the HCN molecule was studied within a modified adiabatic approximation. This approach, in which the positron is treated as a light pseudonucleus with fractional charge, leads to the binding energy of 0.65 mHartree. Using effective positron mass which reproduces the Quantum Monte Carlo binding energy gives an estimation of the two-photon annihilation rate of e ⁺HCN, equal to 0.091 ns⁻¹.

Keywords:

• positron binding
• positronic molecule
• annihilation rate
• batic approximation

Acknowledgements

This work was financed by a statutory activity subsidy from the Polish Ministry of Science and Higher Education for the Faculty of Chemistry of Wrocław University of Technology (‘Experimental and theoretical studies of molecular systems and nanostructures’, contract number S10088). We are also grateful to the authors of freely available computer programs and libraries: PSI3 38, Fudgit 46, gnuplot 47 and QUADPACK 48.