DIFFUSION QUANTUM MONTE-CARLO CALCULATION OF THE BINDING-ENERGY OF POSITRONIUM HYDROXIDE

Using the diffusion quantum Monte Carlo method, the binding energy of positronium hydroxide (alternatively, the positronium affinity of the hydroxyl radical) has been calculated at a new level of accuracy and f ound to be 0.63+/-0.15 eV. Using the same methods, we also calculate t he electron affinity of the hydroxyl radical to be 1.86+/-0.14 eV, whi ch is in agreement with the experimental value. To the authors' knowle dge, this is the only calculation of these quantities for which this e ssential consistency is demonstrated.