Path-integral simulations of zero-point effects for implanted muons in benzene

Valladares, R.M.; Fisher, A. J.; Hayes, W.

doi:10.1016/0009-2614(95)00771-u

Cited by 32 publications

(15 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The incorporation of the PI method into the ab initio molecular dynamic or Monte Carlo simulation techniques has provided us with a powerful tool to study nuclear quantum effects within the BO framework . There have been several recent studies on the theoretical predictions of structural dynamics and hyperfine coupling constants of the muoniated species based on the PI methodology accurately reproducing the relevant experimental data . Despite notable success in the modeling of muoniated radicals, the PI‐based methods are computationally demanding, and therefore, not competent to be used for the majority of chemically interesting systems.…”

Section: Introductionmentioning

confidence: 99%

How intrinsic nuclear nonadiabaticity affects molecular structure, electronic density, and conformational stability: Insights from the multicomponent DFT calculations of Mu/H isotopologues

Goli

Jalili

2018

Int J of Quantum Chemistry

View full text Add to dashboard Cite

In the present work, the formalism of the multicomponent density functional theory is extended to study the open‐shell muoniated radicals of nucleic acid bases adenine, guanine, cytosine, thymine and uracil beyond the adiabatic paradigm. The derived methodology is used to characterize the stationary structures of all conceivable muoniated adducts based on the ab initio nuclear‐electronic approach, which is a mixed intermediate non‐adiabatic/adiabatic framework. The energies, geometries, atomic charges and spin‐density distributions of the muoniated species are scrutinized against their hydrogenated congeners derived within the conventional adiabatic framework. The comparative analysis of the results determines the considerable impact of nuclear quantum effects on the molecular geometry, electronic density and conformational stability while underlining the fact that the extent of the geometrical and spin‐distribution variations upon muonium substitution could be significant and mass dependent.

show abstract

Section: Introductionmentioning

confidence: 99%

How intrinsic nuclear nonadiabaticity affects molecular structure, electronic density, and conformational stability: Insights from the multicomponent DFT calculations of Mu/H isotopologues

Goli

Jalili

2018

Int J of Quantum Chemistry

View full text Add to dashboard Cite

show abstract

“…To this aim, a variety of theoretical and computational approaches were used. 14,[20][21][22][23][24][25][26][27] Successful results have been recently obtained for metallic compounds where an estimation based on the electrostatic potential allowed to identify the muon sites. 28 In this work we want to show that, among the many possible approaches 23,24,28,29 based on a first-principles method, Density Functional Theory (DFT), already well known for its success in studying electronic structure of solids, is further a powerful, accurate and effective tool to explore the µ + -sample interactions on a selected set of experimental acquisitions.…”

Section: Introductionmentioning

confidence: 99%

Ab initiostrategy for muon site assignment in wide band gap fluorides

et al. 2013

View full text Add to dashboard Cite

We report on an ab initio strategy based on Density Functional Theory to identify the muon sites. Two issues must be carefully addressed, muon delocalization about candidate interstitial sites and local structural relaxation of the atomic positions due to µ + -sample interaction. Here, we report on the validation of our strategy on two wide band gap materials, LiF and YF3, where localization issues are important because of the interplay between muon localization and lattice relaxation.

show abstract

“…The angular density of probability obtained using 128 slices was found to be quasi-identical to that obtained using 64, thus P was set to 64 in all the calculations. In the strongly harmonic classical equivalent system, ergodicity is efficiently recovered by using a Langevin thermostat [19][20][21] including a high-quality random number generator [22]. For comparison, we have also computed classical trajectories by setting P =1.…”

mentioning

confidence: 99%

Strong Isotope Effect in Phase II of Dense Solid Hydrogen and Deuterium

et al. 2012

View full text Add to dashboard Cite

Quantum nuclear zero-point motions in solid H2 and D2 under pressure are investigated at 80 K up to 160 GPa by first-principles path-integral molecular dynamics calculations. Molecular orientations are well-defined in phase II of D2, while solid H2 exhibits large and very asymmetric angular quantum fluctuations in this phase, with possible rotation in the (bc) plane, making it difficult to associate a well-identified single classical structure. The mechanism for the transition to phase III is also described. Existing structural data support this microscopic interpretation.Keywords: hydrogen, deuterium, path-integral, quantum fluctuation, broken-symmetry phase Over the past 20 years, pressure-induced structural changes have been studied for most elements up to the 300 GPa range by a combination of synchrotron diamond anvil cell experiments and ab initio calculations. Although hydrogen has probably been the most extensively studied element under pressure, its crystalline structures above 10 GPa are still largely unknown. Experimental structural determination is hampered by hydrogen's weak x-ray scattering cross-section, and the use of neutron diffraction is equally, if not more, difficult. Theoretically, the difficulties stem from the fact that nuclear zero-point motions and exchange contributions can have important effects. Novel quantum many-body states of matter should be expected, such as the recently predicted superconducting/superfluid metallic state [1]. Understanding the phase diagram of hydrogen is thus an open challenge in modern condensed matter physics.The phase diagrams of solid hydrogen and deuterium have been extensively studied by Raman and infra-red vibrational spectroscopies. Phase boundaries have been determined for three phases [2][3][4]. The transition from phase I to II appears to be related to a quantum ordering of the molecules, whereas that from II to III is more likely a classical ordering [5]. A strong difference in pressure has been measured between the I-II boundary line of solids H 2 , HD and D 2 , whereas there is almost none for the II-III phase boundary. X-ray diffraction studies have shown that the mass centers of the molecules remain on an hcp lattice at the I-II and II-III transitions, indicating that these phases are differentiated by a molecular ordering on this lattice [6,7]. The nature of this ordering, however, is still unknown. Neutron diffraction data may rule out some theoretical predictions for phase II of D 2 but are insufficient for determination of the orientational order [6]. Numerous calculations using Density Functional Theory (DFT) have tried to examine structural changes in solid molecular hydrogen under pressure [8]. A very small energy difference between various candidate structures is obtained and the relative stability of these structures may be easily changed by including zero-point energy contributions. The most recent revision of the DFT phase diagram of hydrogen, including zero-point energy at the harmonic level, predicts the P 6 3 /m structure for phase...

show abstract

Path-integral simulations of zero-point effects for implanted muons in benzene

Cited by 32 publications

References 23 publications

How intrinsic nuclear nonadiabaticity affects molecular structure, electronic density, and conformational stability: Insights from the multicomponent DFT calculations of Mu/H isotopologues

How intrinsic nuclear nonadiabaticity affects molecular structure, electronic density, and conformational stability: Insights from the multicomponent DFT calculations of Mu/H isotopologues

Ab initiostrategy for muon site assignment in wide band gap fluorides

Strong Isotope Effect in Phase II of Dense Solid Hydrogen and Deuterium

Contact Info

Product

Resources

About