Topological insulators from the perspective of first-principles calculations

First-principles calculations for insulators at constant polarization.

We develop an exact formalism for performing first-principles calculations for insulators at fixed electric polarization. As shown by Sai, Rabe, and Vanderbilt (SRV) [Phys. Rev. B 66, 104108 (2002)], who designed an approximate method to tackle the same problem, such an approach allows one to map out the energy landscape as a function of polarization, providing a powerful tool for the theoretic...

Magnetic susceptibility of insulators from first principles.

We present an ab initio approach for the computation of the magnetic susceptibility χ of insulators. The approach is applied to compute χ in diamond and in solid neon using density functional theory in the local density approximation, obtaining good agreement with experimental data. In solid neon, we predict an observable dependence of χ upon pressure. 75.20.-g, 71.15.-m, 71.15.Mb Typeset using...

Magnetism of Chromia from First-Principles Calculations

Ammonia synthesis from first-principles calculations.

The rate of ammonia synthesis over a nanoparticle ruthenium catalyst can be calculated directly on the basis of a quantum chemical treatment of the problem using density functional theory. We compared the results to measured rates over a ruthenium catalyst supported on magnesium aluminum spinel. When the size distribution of ruthenium particles measured by transmission electron microscopy was u...

Tight-binding Hamiltonian from first-principles calculations

The tight-binding method attempts to represent the electronic structure of condensed matter using a minimal atomic-orbital like basis set. To compute tight-binding overlap and Hamiltonian matrices directly from first-principles calculations is a subject of continuous interest. Usually, first-principles calculations are done using a large basis set or long-ranged basis set (e.g. muffin-tin orbit...