3VDZ:
reference: Tailoring encodable lanthanide-binding tags as MRI contrast agents., Daughtry KD, Martin LJ, Sarraju A, Imperiali B, Allen KN, Chembiochem. 2012 Nov 26;13(17):2567-74. doi: 10.1002/cbic.201200448. Epub 2012, Nov 13. PMID: 23150430

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).