title: Testing a Variety of Electronic-Structure-Based Methods for the Relative Energies of 5-Formyluracil Crystals.
abstract: The lattice energies of the experimental and several hypothetical crystal structures of the RNA base uracil derivative 5-formyluracil are calculated with a range of methods, based either on the electronic structure of the molecule or the lattice. The explicit modeling of the polarization within the crystal in the model intermolecular potential and the inclusion of an empirical dispersion correction to the periodic density functional energy (DFT-D2) were the only methods able to calculate the energy balance between different conformations, hydrogen bonding, and π-π stacking possibilities sufficiently accurately to give the observed structure as the most stable. Even these two methods underestimated the density of the room temperature structure, showing the need for improvement in the modeling of organic crystal structures.
authors.affiliation: Department of Chemistry, University College London , 20 Gordon Street, London, WC1H 0AJ United Kingdom.
authors.forename: Matthew
authors.initials: M
authors.lastname: Habgood
authors.affiliation: Department of Chemistry, University College London , 20 Gordon Street, London, WC1H 0AJ United Kingdom.
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Price
authors.affiliation: Dipartimento di Chimica, "Sapienza" Università di Roma, P.le Aldo Moro 5, 00185 Rome, Italy.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Portalone
authors.affiliation: Department of Chemistry, University College London , 20 Gordon Street, London, WC1H 0AJ United Kingdom.
authors.forename: Simona
authors.initials: S
authors.lastname: Irrera