5HN2:
reference: Base pairing and structural insights into the 5-formylcytosine in RNA duplex., Wang R, Luo Z, He K, Delaney MO, Chen D, Sheng J, Nucleic Acids Res. 2016 Apr 13. pii: gkw235. PMID: 27079978

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