ERROR opening https://cactus.nci.nih.gov/chemical/structure/c1ccc%28cc1%29%5BSi%5D%28c2ccccc2%29%28O%29O/file?format=sdf&get3d=True -- c1ccc%28cc1%29%5BSi%5D%28c2ccccc2%29%28O%29O could not be loaded.