ATLAS[1]hasrecentlyjoinedGaudi,anopenprojecttodevelopadataprocessingframeworkforHEPexperiments[2],ThedatamodelisoneoftheareaswhereATLAShasextendedmoretheoriginalGaudidesigntomeettheexperiment'sownrequirments.ThispaperdescribesStoreGate,thefirstimplementationoftheATLASDataModel.