Heats of formation of the Criegee formaldehyde oxide and dioxirane

CCSD(T)/CBS calculations plus corrections predict the heats of formation of formaldehyde O-oxide 1 (Criegee intermediate) and dioxirane 2 to be ΔHf0(1)=26.4 kcal/mol and ΔHf0(2)=1.2 kcal/mol at 298 K.