2H5O:
reference: Novel Chromophores and Buried Charges Control Color in mFruits(,)., Shu X, Shaner NC, Yarbrough CA, Tsien RY, Remington SJ, Biochemistry. 2006 Aug 15;45(32):9639-9647. PMID: 16893165

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