4JRD:
reference: Structure of the parallel duplex of poly(A) RNA: evaluation of a 50 year-old prediction., Safaee N, Noronha AM, Rodionov D, Kozlov G, Wilds CJ, Sheldrick GM, Gehring K, Angew Chem Int Ed Engl. 2013 Sep 23;52(39):10370-3. doi: 10.1002/anie.201303461. , Epub 2013 Jun 27. PMID: 23813654

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