Magnesium ion

http://classyfire.wishartlab.com/tax_nodes/C0000001
http://classyfire.wishartlab.com/tax_nodes/C0000422
http://classyfire.wishartlab.com/tax_nodes/C0000428
http://classyfire.wishartlab.com/tax_nodes/C0000428
https://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:18420
http://metacyc.org/META/new-image?type=COMPOUND&object=MG+2
http://www.hmdb.ca/metabolites/HMDB0000547
http://www.genome.jp/dbget-bin/www_bget?cpd:C00305
https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=888
https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?sid=46508750
https://www.chemspider.com/Chemical-Structure.865.html
http://www.bindingdb.org/bind/chemsearch/marvin/MolStructure.jsp?monomerid=15
https://mor.nlm.nih.gov/RxNav/search?searchBy=RXCUI&searchTerm=1426853
https://www.ebi.ac.uk/chebi/searchId.do?chebiId=18420
http://bidd.nus.edu.sg/group/cjttd/ZFTTDDRUG.asp?ID=DCL000876
http://www.pharmgkb.org/drug/PA164712884
https://www.ebi.ac.uk/pdbe-srv/pdbechem/chemicalCompound/show/MG
https://en.wikipedia.org/wiki/Magnesium