ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI=1S/2K.4HNO2.Pt/c;;4*2-1-3;/h;;4*(H,2,3);/q2*+1;;;;;/p-4/file?format=sdf&get3d=True -- InChI=1S/2K.4HNO2.Pt/c;;4*2-1-3;/h;;4*(H,2,3);/q2*+1;;;;;/p-4 could not be loaded.