Double-vertex contribution to the decay rate of orthopositronium

The recently calculated decay rate of orthopositronium differs with the experimental value by 2 1/2 standard deviations. This communication reports a 100-fold improvement in the numerical error estimate for the double-vertex diagram contribution to the decay rate. This improvement reduces the numerical error estimate of the previously calculated decay rate of orthopositronium by 20%. This improvement of the double-vertex diagrams alone does not bring the experimental and calculated values into good agreement; however, the discrepancy is reduced