The molecule is an organophosphate oxoanion that is MgADP which has lost the proton attached to the diphosphate moiety. It contains a magnesium(2+). It is a conjugate base of a MgADP.
magnesium;[[(2R,3S,4R,5R)-5-(6-aminopurin-9-yl)-3,4-dihydroxyoxolan-2-yl]methoxy-oxidophosphoryl] phosphate