A model for the hydrogen-bond-length probability distributions in the crystal structures of small-molecule components of the nucleic acids

: The probability distributions of the N-H...O = C and O-H...O = C hydrogen-bond lengths observed in the crystal structures of the purines, pyrimidines, nucleosides and nucleotides have been fitted to a one-dimensional hydrogen-bond potential-energy function. In order to obtain a quantitative correspondence between the experimental and theoretical distributions, it is necessary to include with the usual hydrogen-bond-type potential-energy function, an effective crystal-packing force and two thermodynamical parameters of the crystal lattice, the Debye temperature and the Gruneisen constant.