Complete (O{sub 7},O{sub 8}) contribution to B{yields}X{sub s{gamma}} at O({alpha}{sub s}{sup 2})

We calculate the set of O({alpha}{sub s}{sup 2}) corrections to the branching ratio and to the photon energy spectrum of the decay process B{yields}X{sub s{gamma}} originating from the interference of diagrams involving the electromagnetic dipole operator O{sub 7} with diagrams involving the chromomagnetic dipole operator O{sub 8}. The corrections evaluated here are one of the elements needed to complete the calculations of the B{yields}X{sub s{gamma}} branching ratio at next-to-next-to-leading order in QCD. We conclude that this set of corrections does not change the central value of the standard model prediction for Br(B{yields}X{sub s{gamma}}) by more than 1%.