  Results of a search for new phenomena in events with large missing transverse
momentum and a Higgs boson decaying to two photons are reported. Data from
proton-proton collisions at a center-of-mass energy of 8 TeV and corresponding
to an integrated luminosity of 20.3 fb$^{-1}$ have been collected with the
ATLAS detector at the LHC. The observed data are well described by the expected
Standard Model backgrounds. Upper limits on the cross section of events with
large missing transverse momentum and a Higgs boson candidate are also placed.
Exclusion limits are presented for models of physics beyond the Standard Model
featuring dark-matter candidates.
