text: has an extended (chain or network) structure in which xenon and oxygen have coordination numbers of four and two respectively. The geometry at xenon is square planar, consistent with VSEPR theory for four ligands and two lone pairs (or AXE in the notation of VSEPR theory).
  In addition, the existence of an XeO molecule was predicted by an ab initio quantum chemistry method several years earlier by Pyykkö and Tamm, but these authors did not consider an extended structure.