Comparative first-principles structural and vibrational properties of rutile and anatase TiO.

The structural and vibrational properties of two polymorphs of TiO, rutile and anatase, have been investigated by first-principles methods at different levels of exchange-correlational (XC) energy functionals in density functional theory (DFT). Reports in the literature to date are contradictory regarding the stability of the rutile phase using DFT XC-functionals more sophisticated than simple local-density approximation. Here the PBEsol generalized gradient approximation (GGA), TPSS meta-GGA, and HSE06 hybrid functionals have been employed to demonstrate the XC-functional effects on the calculated structural, phonon and thermodynamic properties of rutile and anatase TiO.

Electronic structure and high-temperature thermochemistry of BaZrO perovskite from first-principles calculations.

ABO perovskites are attractive candidates for high-temperature mixed ionic electronic conduction processes, due to their ability to produce mixed oxidation states and accommodate oxygen vacancies. Here, we examine the electronic structure and high-temperature thermochemistry of stoichiometric and non-stoichiometric cubic BaZrO perovskites for high defect concentration (δ = 0-0.5) using first-principles density functional theory (DFT) and density functional perturbation theory (DFPT) calculations.

Roles of Hydration for Inducing Decomposition of 2-Deoxy-d-ribose by Ionization of Oxygen K-Shell Electrons.

To experimentally investigate the role of hydration in the initial process of the decomposition of 2-deoxy-d-ribose (dR), which is a major component of the DNA backbone, we used mass spectrometry to monitor the ions desorbing from hydrated dR films exposed to monochromatic soft X rays (560 eV). The X-ray photons preferentially ionize the K-shell electrons of the oxygen atoms in DNA. Hydrated dR samples were prepared under vacuum by exposing a cooled (∼150 K) dR film deposited on a Si substrate to water vapor.

Investigation of the fragmentation of core-ionised deoxyribose: a study as a function of the tautomeric form.

We have investigated the gas phase fragmentation dynamics following the core ionisation of 2-deoxy-D-ribose (dR), a major component in the DNA chain. To that aim, we use state-of-the-art ab initio Density Functional Theory-based Molecular Dynamics simulations. The ultrafast dissociation dynamics of the core-ionised biomolecule, prior Auger decay, is first modelled for 10 fs to generate initial configurations (atomic positions and velocities) for the subsequent dynamics of the doubly ionised biomolecule in the ground state.