ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI=1S/6C6H5.2Sn/c6*1-2-4-6-5-3-1;;/h6*1-5H;;/file?format=sdf&get3d=True -- InChI=1S/6C6H5.2Sn/c6*1-2-4-6-5-3-1;;/h6*1-5H;; could not be loaded.