O(α)Corrections to the Decay Rate of Orthopositronium

The results of a new calculation of the $O\left(\alpha \right)$ corrections to the decay rate of orthopositronium are presented. The rate is $\Gamma ={\Gamma }^0[1-(\frac{\alpha }{\pi }\left)\right(10.348\mathrm{}\pm 0.070\left)\right]=(7.0379\pm 0.0012)\times {10}^6$ ${\sec }^{-1\mathrm{}}$. This is substantially below all measured rates as well as previous theoretical estimates. We provide further justification for the computational techniques employed.