  Precise numerical calculation of radiofrequency intervals between hyperfine
sublevels of the $(37,35)$ state of the antiprotonic helium-4 atom is
presented. Theoretical consideration includes the QED corrections of order
$m\alpha^6$ to the electron spin-orbit interaction. The effective Hamiltonian
is derived using the formalism of the nonrelativistic quantum electrodynamics
(NRQED).
