density-functional perturbation theory ∂E(λ) ∂λ i = n λ (r)V i (r)dr HF V (r) = V 0 (r) + i λ i V i (r) E(λ) = min n F[n] + V λ (r)n(r) n(r)dr = N DFT density-functional perturbation theory ∂E(λ) ∂λ i ...
If however the ground state is perturbed very lightly, typically in such a manner as to leave the system close to its electronic ground state, one can easily apply the traditional quantum formalism for perturbation theory, giving density functional perturbation theory (DFPT). This approach was ...
M. Stengel, Flexoelectricity from density-functional perturbation theory, Phys. Rev. B. 88, 174106 (2013).Stengel M. Flexoelectricity from density-functional perturbation theory. Physical Review B. 88(17): 174106, 2013.Stengel M. Flexoelectricity from density-functional perturbation theory . Phys. ...
gration. By density functional perturbation theory (DFPT), a 4×4×4 Monkhorst–Pack q–vector grid are calculated and the full phonon dispersion is obtained through Fourier interpola- tion. 3. Main results and analyses 3.1. Electronic structure At first, the theoretical equilibriumcrystal struct...
We generalize density-functional perturbation theory for lattice dynamics to Vanderbilt's ultrasoft pseudopotential scheme. This formulation accounts for the nonorthogonality of the orbitals, the augmentation of the electron density, and the dependence of the generalized orthogonality constraint on the atomic...
Mourad, A mathematical perspective on density functional pertur- bation theory, Nonlinearity 27 (2014) 1999-2033.E. Cances and N. Mourad, A mathematical perspective on density functional perturbation theory, Nonlinearity, 27 (2014), pp. 1999-2033....
Generalized variational density functional perturbation theory.We present an implementation of variational perturbation theory in the framework of density functional theory. We use an ab initio pseudopotential scheme with a plane wave basis set and expand the energy functional up to second order in the ...
We first introduce some of the thermal properties of interest and describe how they can be calculated in the framework of the QHA; then we briefly recall Density-Functional Perturbation Theory as a tool for calculating phonons from first principles, and present some codes that implement it; ...
Many technological applications depend on the response of materials to electric fields, but available databases of such responses are limited. Here, we explore the infrared, piezoelectric and dielectric properties of inorganic materials by combining high-throughput density functional perturbation theory and ...
physics of electron-phonon coupling in large-scale materials, which has the potential to outperform the computationally expensive traditional methods of frozen phonon or density functional perturbation theory38. Furthermore, one may combine the deep learning method with advanced methods beyond the DFT ...