Dynamical dimer method for the determination of transition states with ab initio molecular dynamics

A dynamical formulation of the dimer method for the determination of transition states is presented. The method is suited for ab-initio molecular dynamics using the fictitious Lagrangian formulation. The method has been applied to the con-rotatory ring opening of chloro-cyclo-butadiene, an example, where the application of the drag method is problematic.Comment: The final modified version will be published in JCP. After it is published, it will be found at http://jcp.aip.org

Structural and Electronic Properties of the Interface between the High-k oxide LaAlO3 and Si(001)

The structural and electronic properties of the LaAlO3/Si(001) interface are determined using state-of-the-art electronic structure calculations. The atomic structure differs from previous proposals, but is reminiscent of La adsorption structures on silicon. A phase diagram of the interface stability is calculated as a function of oxygen and Al chemical potentials. We find that an electronically saturated interface is obtained only if dopant atoms segregate to the interface. These findings raise serious doubts whether LaAlO3 can be used as an epitaxial gate dielectric.Comment: 4 pages, 5 figure

Accurate hyperfine couplings for C59N

We identify the shortcomings of existing ab initio quantum chemistry calculations for the hyperfine couplings in the recently characterized azafullerene, C59N. Standard gaussian basis sets in the context of all--electron calculations are insufficient to resolve the spin density near the cores of the atoms. Using the Projector Augmented Wave method implemented on top of a standard pseudopotential plane--wave density--functional framework, we compute significantly more accurate values for the Fermi contact interaction.Comment: 8 pages, 4 figure

Electronic structure methods: Augmented Waves, Pseudopotentials and the Projector Augmented Wave Method

The main goal of electronic structure methods is to solve the Schroedinger equation for the electrons in a molecule or solid, to evaluate the resulting total energies, forces, response functions and other quantities of interest. In this paper we describe the basic ideas behind the main electronic structure methods such as the pseudopotential and the augmented wave methods and provide selected pointers to contributions that are relevant for a beginner. We give particular emphasis to the Projector Augmented Wave (PAW) method developed by one of us, an electronic structure method for ab-initio molecular dynamics with full wavefunctions. We feel that it allows best to show the common conceptional basis of the most widespread electronic structure methods in materials science.Comment: to appear in: Handbook of Materials Modeling; Volume 1: Methods and Models, Sidney Yip (Ed.); Kluwer Academic Publisher