  Taking into account Goodenough's superexchange rules, including both full
structural relaxation and spin-orbit coupling, and checking strong correlation
effects, we look for compensated half metals within the class of oxide double
perovskites materials. Identifying likely half metallic (or half semimetallic)
antiferromagnets, the full complications including orbital magnetism are
included in order to arrive at realistic predictions of designed magnetic
compounds with (near) vanishing net moment. After sorting through several
candidates that have not been considered previously, two materials,
K$_2$MnRhO$_6$ and La$_2$CrWO$_6$, remain as viable candidates. An important
factor is obtaining compounds either with very small induced orbital moment
(helped by closed subshells) or with an orbital moment that compensates the
spin-orbit driven degradation of half metallic character. While thermodynamic
stability of these materials cannot be ensured, the development of
layer-by-layer oxide deposition techniques does not require that materials be
thermodynamically stable to be synthesized.
