scholarly journals Uncertainty of exchange‐correlation functionals in density functional theory calculations for lithium‐based solid electrolytes on the case study of lithium phosphorus oxynitride

Author(s):  
Pascal Henkel ◽  
Doreen Mollenhauer
RSC Advances ◽  
2016 ◽  
Vol 6 (103) ◽  
pp. 101216-101225 ◽  
Author(s):  
Renan Augusto Pontes Ribeiro ◽  
Sergio Ricardo de Lazaro ◽  
Carlo Gatti

In this study, ab initio density functional theory calculations were performed on ATiO3 (A = Mn, Fe, Ni) materials for multiferroic applications.


2002 ◽  
Vol 716 ◽  
Author(s):  
Maciej Gutowski ◽  
John E. Jaffe ◽  
Chun-Li Liu ◽  
Matt Stoker ◽  
Anatoli Korkin

AbstractIt is known that the chemistries of hafnium and zirconium are more nearly identical than for any other two congeneric elements. Thus, both zirconia and hafnia, with the dielectric constant K > 20, have emerged as potential replacements for silica (K = 3.9) as a gate dielectric. We report an important difference between the zirconia/Si and hafnia/Si interfaces based on density functional theory calculations with the Perdew-Wang 91 exchange-correlation functional on the oxides, silicides, and silicates of Zr and Hf. The zirconia/Si interface has been found to be unstable with respect to formation of silicides whereas the hafnia/Si interface is stable. The difference between the two interfaces results from the fact that HfO2 is more stable than ZrO2 (i.e. has a larger heat of formation from its constituent elements) by more than 53 kJ/mol. The hafnium silicides, on the other hand, are less stable than zirconium silicides by ca. 20 kJ/mol.


2020 ◽  
Author(s):  
Rachel Garrick ◽  
Amir Natan ◽  
Tim Gould ◽  
Leeor Kronik

Hybrid functionals have proven to be of immense practical value in density functional theory calculations. While they are often thought to be a heuristic construct, it has been established that this is in fact not the case. Here, we present a rigorous and formally exact analysis of generalized Kohn-Sham (GKS) density functional theory of hybrid functionals, in which exact remainder exchange-correlation potentials combine with a fraction of Fock exchange to produce the correct ground state density. First, we extend formal GKS theory by proving a generalized adiabatic connection theorem. We then use this extension to derive two different definitions for a rigorous distinction between multiplicative exchange and correlation components - one new and one previously postulated. We examine their density-scaling behavior and discuss their similarities and differences. We then present a new algorithm for obtaining exact GKS potentials by inversion of accurate reference electron densities and employ this algorithm to obtain exact potentials for simple atoms and ions. We establish that an equivalent description of the many-electron problem is indeed obtained with any arbitrary global fraction of Fock exchange and we rationalize the Fock-fraction dependence of the computed remainder exchange-correlation potentials in terms of the new formal theory. Finally, we use the exact theoretical framework and numerical results to shed light on the exchange-correlation potential used in approximate hybrid functional calculations and to assess the consequences of different choices of fractional exchange.<br><br>


2019 ◽  
Vol 21 (21) ◽  
pp. 10923-10930 ◽  
Author(s):  
Lin Chen ◽  
Ton V. W. Janssens ◽  
Henrik Grönbeck

A general challenge in density functional theory calculations is to simultaneously account for different types of bonds. Here, different exchange–correlation functionals are explored for O2 dissociation over Cu(NH3)2+ complexes in Cu-Chabazite.


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