Are isolated nucleic acid bases really planar? A Car-Parrinello molecular dynamics study.
Isayev O, Furmanchuk A, Shishkin OV, Gorb L, Leszczynski J. Are isolated nucleic acid bases really planar? A Car-Parrinello molecular dynamics study. J Phys Chem B. 2007 Apr 05; 111(13):3476-80.