  We present predictions for the prompt-neutrino flux arising from the decay of
charmed mesons and baryons produced by the interactions of high-energy cosmic
rays in the Earth's atmosphere, making use of a QCD approach on the basis of
the general-mass variable-flavor-number scheme for the description of charm
hadroproduction at next-to-leading order, complemented by a consistent set of
fragmentation functions. This same scheme is used for the description of charm
hadroproduction at both the Tevatron and the Large Hadron Collider. We compare
the theoretical predictions to those already obtained by our and other groups
with different theoretical approaches. We provide comparisons with the
experimental results obtained by the IceCube Collaboration and we discuss
implications for parton distribution functions.
