ERROR opening https://cactus.nci.nih.gov/chemical/structure/InChI=1S/C20H16N4/c1(3-7-13-21-17-19-11-5-9-15-23-19)2-4-8-14-22-18-20-12-6-10-16-24-20/h1-2,5-6,9-12,15-18H,13-14H2/b2-1?,21-17+,22-18+/file?format=sdf&get3d=True  -- InChI=1S/C20H16N4/c1(3-7-13-21-17-19-11-5-9-15-23-19)2-4-8-14-22-18-20-12-6-10-16-24-20/h1-2,5-6,9-12,15-18H,13-14H2/b2-1?,21-17+,22-18+ could not be loaded.