title: Electronic structure of wet DNA.
abstract: The electronic properties of a Z-DNA crystal synthesized in the laboratory are investigated by means of density-functional theory Car-Parrinello calculations. The electronic structure has a gap of only 1.28 eV. This separates a manifold of 12 occupied states which came from the pi guanine orbitals from the lowest empty states in which the electron is transferred to the Na+ from PO-4 groups and water molecules. We have evaluated the anisotropic optical conductivity. At low frequency the conductivity is dominated by the pi-->Na+ transitions. Our calculation demonstrates that the cost of introducing electron holes in wet DNA strands could be lower than previously anticipated.
authors.affiliation: Università di Firenze, Dipartimento di Chimica, Via della Lastruccia 3, I-50019 Sesto Fiorentino, Italy.
authors.forename: Francesco Luigi
authors.initials: FL
authors.lastname: Gervasio
authors.forename: Paolo
authors.initials: P
authors.lastname: Carloni
authors.forename: Michele
authors.initials: M
authors.lastname: Parrinello
mesh_terms: D003460:Crystallization; D004247:DNA / Q000737:chemistry*; D006860:Hydrogen Bonding; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides / Q000138:chemical synthesis / Q000737:chemistry; D014867:Water / Q000737:chemistry*
chemical_list: D009841:Oligonucleotides; D014867:Water; D004247:DNA