In a recent Letter [T. Dornheim et al., Phys. Rev. Lett. 117, 156403 (2016)PRLTAO0031-900710.1103/PhysRevLett.117.156403], we presented the first quantum Monte Carlo (QMC) results for the warm dense electron gas in the thermodynamic limit. However, a complete parametrization of the exchange-correlation free energy with respect to density, temperature, and spin polarization remained out of reach due to the absence of (i) accurate QMC results below θ=k_{B}T/E_{F}=0.5 and (ii) QMC results for spin polarizations different from the paramagnetic case. Here we overcome both remaining limitations. By closing the gap to the ground state and by performing extensive QMC simulations for different spin polarizations, we are able to obtain the first completely ab initio exchange-correlation free energy functional; the accuracy achieved is an unprecedented ∼0.3%. This also allows us to quantify the accuracy and systematic errors of various previous approximate functionals.
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http://dx.doi.org/10.1103/PhysRevLett.119.135001 | DOI Listing |
J Mol Model
January 2025
Department of Physics, Faculty of Sciences, Shahrekord University, P.O. Box 115, Shahrekord, Iran.
J Comput Chem
January 2025
School of Physics, The University of Sydney, Sydney, New South Wales, Australia.
Using first principles calculations we investigate cobalt-coordinated tetracyanoquinodimethane (R-CoTCNQ) as a potential catalyst for the CO electroreduction reaction (COERR). We determine that exchange-correlation functionals beyond the generalized gradient approximation (GGA) are required to accurately describe the spin properties of R-CoTCNQ, therefore, the meta-GGA rSCAN functional is used in this study. The free energy COERR reaction pathways are calculated for the reduced catalyst ([R-CoTCNQ]) with reaction products HCOOH and HCHO predicted depending on our choice of electrode potential.
View Article and Find Full Text PDFACS Omega
December 2024
Physics Department, Federal University of Rondônia, 76801-974 Porto Velho, Brazil.
We have investigated the Raman spectrum and excitonic effects of the novel 2D TaNiTe structure. The monolayer is an indirect band gap semiconductor with an electronic band gap value of 0.09 and 0.
View Article and Find Full Text PDFJ Chem Phys
December 2024
Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544-5263, USA.
Solutions and minerals containing sulfate (SO42-), and Ca2+ and Mg2+ cations, are ubiquitous throughout the lithosphere and are significant components of seawater, thus presenting a prototypical system for the study of strong electrolytes and crystal nucleation mechanisms. However, despite their relative abundance, key questions remain unanswered about the most fundamental atomic-level steps of their mineralization pathways and aqueous dynamics. Here, we carry out enhanced sampling multi-level molecular dynamics (MD) embedded correlated wavefunction theory simulations to elucidate ion-pairing mechanisms for Mg-SO4 and Ca-SO4 in concentrated aqueous solution, accurately capturing effects arising from both structural dynamics and electron exchange-correlation.
View Article and Find Full Text PDFChem Soc Rev
November 2024
School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
Thermophysical properties of adsorbates and gas-phase species define the free energy landscape of heterogeneously catalyzed processes and are pivotal for an atomistic understanding of the catalyst performance. These thermophysical properties, such as the free energy or the enthalpy, are typically derived from density functional theory (DFT) calculations. Enthalpies are species-interdependent properties that are only meaningful when referenced to other species.
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