English
Related papers

Related papers: Density Functional Calculations On First-Row Trans…

200 papers

Exchange-correlation potentials vxc and energy densities exc are derived for integer and fractional electron counts using an orbital-averaged Kohn-Sham inversion procedure. The reference densities for inversion come from full configuration…

Chemical Physics · Physics 2025-04-30 Vaibhav Khanna , Bikash Kanungo , Jeffrey Hatch , Joshua Kammeraad , Paul M. Zimmerman

In this article, we derive fully guaranteed error bounds for the energy of convex nonlinear mean-field models. These results apply in particular to Kohn-Sham equations with convex density functionals, which includes the reduced Hartree-Fock…

Energy barriers, which control the rates of chemical reactions, are seriously underestimated by computationally-efficient semi-local approximations for the exchange-correlation energy. The accuracy of a semi-local density functional…

Chemical Physics · Physics 2023-11-06 Bikash Kanungo , Aaron D. Kaplan , Chandra Shahi , Vikram Gavini , John P. Perdew

Perhaps the simplest first-principles approach to electronic structure is to fit the charge distribution of each orbital pair and use those fits wherever they appear in the entire electron-electron (EE) interaction energy. The charge…

Chemical Physics · Physics 2015-11-10 Brett I Dunlap , Mark C Palenik

Using the optimized effective potential method in conjunction with the semi-analytical approximation due to Krieger, Li and Iafrate, we have performed fully self-consistent exact exchange-only density-functional calculations for diatomic…

chem-ph · Physics 2008-02-03 T. Grabo , E. K. U. Gross

Energies for the lowest 56 levels, belonging to the 3s$^2$3p, 3s3p$^2$, 3p$^3$, 3s$^2$3d, 3s3p3d, 3s$^2$4$\ell$ and 3s$^2$5$\ell$ configurations of Si II, are calculated using the {\sc grasp} (General-purpose Relativistic Atomic Structure…

Instrumentation and Methods for Astrophysics · Physics 2015-06-19 KM Aggarwal , FP Keenan

A direct orbital optimization method is presented for density functional calculations of excited electronic states using either a real space grid or a plane wave basis set. The method is variational, provides atomic forces in the excited…

Computational Physics · Physics 2022-11-09 Aleksei V. Ivanov , Gianluca Levi , Elvar Ö. Jónsson , Hannes Jónsson

The most widely-used density functionals for the exchange-correlation energy are inexact for one-electron systems. Their self-interaction errors can be severe in some applications. The problem is not only to correct the self-interaction…

Chemical Physics · Physics 2009-11-10 Stephan Kümmel , John P. Perdew

Excited electronic states of molecules and solids play a fundamental role in fields such as catalysis and electronics. In electronic structure calculations, excited states typically correspond to saddle points on the surface described by…

Accurately describing excited states within Kohn-Sham (KS) density functional theory (DFT), particularly those which induce ionization and charge transfer, remains a great challenge. Common exchange-correlation (xc) approximations are…

Materials Science · Physics 2021-02-09 Eli Kraisler , M. J. P. Hodgson , E. K. U. Gross

Standard density functional approximations often give questionable results for odd-electron radical complexes, with the error typically attributed to self-interaction. In density corrected density functional theory (DC-DFT), certain classes…

Chemical Physics · Physics 2015-06-19 Min-Cheol Kim , Eunji Sim , Kieron Burke

Octahedral Fe$^{2+}$ molecules are particularly interesting as they often exhibit a spin-crossover transition. In spite of the many efforts aimed at assessing the performances of density functional theory for such systems, an…

Materials Science · Physics 2015-06-05 A. Droghetti , D. Alfè , S. Sanvito

Absolute cross sections for electron-impact single ionisation (EISI) of multiply charged tungsten ions (W$^{q+}$) with charge states in the range $ 11 \leq q \leq 18$ in the electron-ion collision energy ranges from below the respective…

Atomic Physics · Physics 2020-01-08 D. Schury , A. Borovik, , B. Ebinger , F. Jin , K. Spruck , A. Müller , S. Schippers

Finite temperature Green's function technique is used to calculate the energies and damping rates of elementary excitations of the homogeneous, dilute, spin-1 Bose gases below the Bose-Einstein condensation temperature both in the density…

Soft Condensed Matter · Physics 2009-11-10 Gergely Szirmai , Peter Szepfalusy , Krisztian Kis-Szabo

The excited electronic states involved in the optical cycle preparation of a pure spin state of the negatively charged NV-defect in diamond are calculated using the HSE06 hybrid density functional and variational optimization of the…

Materials Science · Physics 2025-10-29 Lei Sun , Elvar Örn Jónsson , Aleksei Ivanov , Ji Chen , Hannes Jónsson

The role of the exchange-correlation potential and the exchange-correlation kernel in the calculation of excitation energues from time-dependent density functional theory is studied. Excitation energies of the He and Be atoms are…

Materials Science · Physics 2007-05-23 Martin Petersilka , E. K. U. Gross , Kieron Burke

We consider three recent large-scale calculations for the radiative and electron-impact excitation data of N IV, carried out with different methods and codes. The scattering calculations employed the relativistic Dirac $R$-matrix (DARC)…

Solar and Stellar Astrophysics · Physics 2019-02-20 G. Del Zanna , L. Fernandez-Menchero , N. R. Badnell

This chapter presents the development of a density functional theory (DFT)-based method for accurate, reliable treatment of various resonances in atoms. Many of these are known to be notorious for their strong correlation, proximity to more…

Chemical Physics · Physics 2019-04-19 Amlan K. Roy

The reported new algorithm determines the exact exchange potential v_x in a iterative way using energy and orbital shifts (ES, OS) obtained - with finite-difference formulas - from the solutions (occupied orbitals and their energies) of the…

Atomic Physics · Physics 2015-05-20 M. Cinal , A. Holas

In this article we present a novel semi-analytical approach to calculate first-order electron-vibration coupling constants within the framework of density functional theory. It combines analytical expressions for the first-order derivative…

Mesoscale and Nanoscale Physics · Physics 2013-11-12 Marius Bürkle , Janne K. Viljas , Thomas J. Hellmuth , Elke Scheer , Florian Weigend , Gerd Schön , Fabian Pauly