scholarly journals Binding and Diffusion of Lithium in Graphite: Quantum Monte Carlo Benchmarks and Validation of van der Waals Density Functional Methods

2014 ◽  
Vol 10 (12) ◽  
pp. 5318-5323 ◽  
Author(s):  
P. Ganesh ◽  
Jeongnim Kim ◽  
Changwon Park ◽  
Mina Yoon ◽  
Fernando A. Reboredo ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Quantum Monte Carlo ◽  
Density Functional ◽  
Van Der Waals ◽  
Density Functional Methods ◽  
Functional Methods ◽  
And Diffusion

scholarly journals Quantum Monte Carlo Study of Silicon Self-interstitial Defects

VLSI Design ◽  
2001 ◽  
Vol 13 (1-4) ◽  
pp. 229-235 ◽  
Author(s):  
W.-K. Leung ◽  
R. J. Needs ◽  
G. Rajagopal ◽  
S. Itoh ◽  
S. Ihara
Keyword(s):  
Monte Carlo ◽  
Quantum Monte Carlo ◽  
Density Functional ◽  
Monte Carlo Study ◽  
Functional Theory ◽  
Self Diffusion ◽  
A Value ◽  
Interstitial Defects ◽  
Quantum Monte Carlo Methods ◽  
And Diffusion

We give a brief description of the variational and diffusion quantum Monte Carlo methods and their application to the study of self-interstitial defects in silicon. The diffusion quantum Monte Carlo calculations give formation energies for the most stable defects of about 4.9 eV, which is considerably larger than the values obtained in density functional theory methods. The quantum Monte Carlo results indicate a value for the formation+migration energy of the self-interstitial contribution to self-diffusion of about 5 eV, which is consistent with the experimental data.

scholarly journals Hydrogen storage on metal oxide model clusters using density-functional methods and reliable van der Waals corrections

2014 ◽  
Vol 16 (11) ◽  
pp. 5382 ◽  
Author(s):  
Julian Gebhardt ◽  
Francesc Viñes ◽  
Patrick Bleiziffer ◽  
Wolfgang Hieringer ◽  
Andreas Görling
Keyword(s):  
Metal Oxide ◽  
Hydrogen Storage ◽  
Density Functional ◽  
Van Der Waals ◽  
Density Functional Methods ◽  
Functional Methods

scholarly journals Hard sphere fluids at a soft repulsive wall: A comparative study using Monte Carlo and density functional methods

2011 ◽  
Vol 134 (21) ◽  
pp. 214706 ◽  
Author(s):  
Debabrata Deb ◽  
Alexander Winkler ◽  
Mohammad Hossein Yamani ◽  
Martin Oettel ◽  
Peter Virnau ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Comparative Study ◽  
Hard Sphere ◽  
Density Functional ◽  
Density Functional Methods ◽  
Functional Methods

scholarly journals Non-Covalent Forces in Naphthazarin—Cooperativity or Competition in the Light of Theoretical Approaches

2021 ◽  
Vol 22 (15) ◽  
pp. 8033
Author(s):  
Aneta Jezierska ◽  
Kacper Błaziak ◽  
Sebastian Klahm ◽  
Arne Lüchow ◽  
Jarosław J. Panek
Keyword(s):  
Monte Carlo ◽  
Perturbation Theory ◽  
Potential Energy ◽  
Proton Transfer ◽  
Ir Spectra ◽  
Quantum Monte Carlo ◽  
Density Functional ◽  
Theoretical Approaches ◽  
Study Results ◽  
Intramolecular Hydrogen

Non-covalent interactions responsible for molecular features and self-assembly in Naphthazarin C polymorph were investigated on the basis of diverse theoretical approaches: Density Functional Theory (DFT), Diffusion Quantum Monte Carlo (DQMC), Symmetry-Adapted Perturbation Theory (SAPT) and Car-Parrinello Molecular Dynamics (CPMD). The proton reaction paths in the intramolecular hydrogen bridges were studied. Two potential energy minima were found indicating that the proton transfer phenomena occur in the electronic ground state. Diffusion Quantum Monte Carlo (DQMC) and other levels of theory including Coupled Cluster (CC) employment enabled an accurate inspection of Potential Energy Surface (PES) and revealed the energy barrier for the proton transfer. The structure and reactivity evolution associated with the proton transfer were investigated using Harmonic Oscillator Model of Aromaticity - HOMA index, Fukui functions and Atoms In Molecules (AIM) theory. The energy partitioning in the studied dimers was carried out based on Symmetry-Adapted Perturbation Theory (SAPT) indicating that dispersive forces are dominant in the structure stabilization. The CPMD simulations were performed at 60 K and 300 K in vacuo and in the crystalline phase. The temperature influence on the bridged protons dynamics was studied and showed that the proton transfer phenomena were not observed at 60 K, but the frequent events were noticed at 300 K in both studied phases. The spectroscopic signatures derived from the CPMD were computed using Fourier transformation of autocorrelation function of atomic velocity for the whole molecule and bridged protons. The computed gas-phase IR spectra showed two regions with OH absorption that covers frequencies from 2500 cm−1 to 2800 cm−1 at 60 K and from 2350 cm−1 to 3250 cm−1 at 300 K for both bridged protons. In comparison, the solid state computed IR spectra revealed the environmental influence on the vibrational features. For each of them absorption regions were found between 2700–3100 cm−1 and 2400–2850 cm−1 at 60 K and 2300–3300 cm−1 and 2300–3200 cm−1 at 300 K respectively. Therefore, the CPMD study results indicated that there is a cooperation of intramolecular hydrogen bonds in Naphthazarin molecule.

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