Multiscale quantum/atomistic coupling using constrained density functional theory

Constrained density functional theory.

Constrained Density-Functional Theory—Configuration Interaction

In this thesis, I implemented a method for performing electronic structure calculations, “Constrained Density Functional Theory–Configuration Interaction” (CDFT-CI), which builds upon the computational strengths of Density Functional Theory and improves upon it by including higher level treatments of electronic correlation which are not readily available in Density-Functional Theory but are a k...

Nonadiabatic potential-energy surfaces by constrained density-functional theory

Nonadiabatic effects play an important role in many chemical processes. In order to study the underlying nonadiabatic potential-energy surfaces PESs , we present a locally constrained density-functional theory approach, which enables us to confine electrons to subspaces of the Hilbert space, e.g., to selected atoms or groups of atoms. This allows one to calculate nonadiabatic PESs for defined c...

Electron-phonon coupling in metallic solids from density functional theory

We present a study of electron-phonon coupling and superconductivity in metallic systems, based on first-principles electronic structure and linear response calculations. Our results are based on the density functional theory and are derived by using the full-potential linear muffin-tin orbitals method. In particular, calculations for phonon spectra, Eliashberg spectral function, and electron-p...

Spin–spin coupling tensors by density-functional linear response theory

Density-functional theory ~DFT! calculations of indirect nuclear magnetic resonance spin–spin coupling tensors J, with the anisotropic but symmetric parts being the particular concern, are carried out for a series of molecules with the linear response ~LR! method. For the first time, the anisotropic components of J are reported for a hybrid functional. Spin–spin tensors calculated using the loc...