  A closed analytic expression is given for the spectrum of low energy photons
in the annihilation of orthopositronium, which expression sums all the effects
of the Coulomb interaction between the electron and the positron. The
applicability of the formula is limited only by the condition $\omega_\gamma
\ll m_e$. In the region $\omega_\gamma \gg m_e \alpha^2$ the Coulomb
interaction term gives the leading at low energy one-loop correction,
proportional to $\alpha \sqrt{m_e/\omega_\gamma}$, to the decay spectrum. The
constant in $\omega_\gamma$ radiative term in the one-loop correction to the
spectrum is also presented here in an analytic form.
