Simulation of quantum zero-point effects in water using a frequency-dependent thermostat

Ganeshan, Sriram; Ramı́rez, Rafael; Fernández-Serra, Mariví

doi:10.1103/physrevb.87.134207

Cited by 16 publications

(30 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To study the NQE, the dynamics of nuclei has to be treated quantum mechanically, and to this end path-integral MD (PIMD) and Monte Carlo methods are normally used. Recently, the semi-classical Langevin equation was used to partially account for the nuclear quantum effect [17][18][19][20][21][22][23][24][25]. The idea is to simply attach one artificial quantum thermal bath (QTB) to each nuclear DoF.…”

Section: Nuclear Quantum Effect In Molecules and Solidsmentioning

confidence: 99%

See 1 more Smart Citation

Semi-classical generalized Langevin equation for equilibrium and nonequilibrium molecular dynamics simulation

Kai-Lun

Hedegård

et al. 2019

Progress in Surface Science

View full text Add to dashboard Cite

Molecular dynamics (MD) simulation based on Langevin equation has been widely used in the study of structural, thermal properties of matters in difference phases. Normally, the atomic dynamics are described by classical equations of motion and the effect of the environment is taken into account through the fluctuating and frictional forces. Generally, the nuclear quantum effects and their coupling to other degrees of freedom are difficult to include in an efficient way. This could be a serious limitation on its application to the study of dynamical properties of materials made from light elements, in the presence of external driving electrical or thermal fields. One example of such system is single molecular dynamics on metal surface, an important system that has received intense study in surface science. In this review, we summarize recent effort in extending the Langevin MD to include nuclear quantum effect and their coupling to flowing electrical current. We discuss its applications in the study of adsorbate dynamics on metal surface, current-induced dynamics in molecular junctions, and quantum thermal transport between different reservoirs.

show abstract

Section: Nuclear Quantum Effect In Molecules and Solidsmentioning

confidence: 99%

“…Ceriotti et al took an important step further [17,20,22,23,68,70,164]. We have mentioned that, given the full Hamiltonian of the global system, the parameters entering the SGLE are derivable from the microscopic Hamiltonian.…”

Section: Nuclear Quantum Effect In Molecules and Solidsmentioning

confidence: 99%

Semi-classical generalized Langevin equation for equilibrium and nonequilibrium molecular dynamics simulation

Kai-Lun

Hedegård

et al. 2019

Progress in Surface Science

View full text Add to dashboard Cite

show abstract

“…20 Ganeshan and coworkers proposed a deterministic approach to suppress ZPEL, which unfortunately requires the knowledge of the vibration normal coordinates prior to the simulation. 19 Here, we investigate the conditions leading to the ZPEL within QTB-MD simulations in various systems in order to get a better understanding of the validity of the QTB method. More precisely, we focus on the conditions and the parameters that influence the ZPEL and on the consequences for the system's properties.…”

Section: Introductionmentioning

confidence: 99%

Zero-Point Energy Leakage in Quantum Thermal Bath Molecular Dynamics Simulations

Brieuc

Bronstein

Dammak

et al. 2016

J. Chem. Theory Comput.

View full text Add to dashboard Cite

The quantum thermal bath (QTB) has been presented as an alternative to path-integral-based methods to introduce nuclear quantum effects in molecular dynamics simulations. The method has proved to be efficient, yielding accurate results for various systems. However, the QTB method is prone to zero-point energy leakage (ZPEL) in highly anharmonic systems. This is a well-known problem in methods based on classical trajectories where part of the energy of the high-frequency modes is transferred to the low-frequency modes leading to a wrong energy distribution. In some cases, the ZPEL can have dramatic consequences on the properties of the system. Thus, we investigate the ZPEL by testing the QTB method on selected systems with increasing complexity in order to study the conditions and the parameters that influence the leakage. We also analyze the consequences of the ZPEL on the structural and vibrational properties of the system. We find that the leakage is particularly dependent on the damping coefficient and that increasing its value can reduce and, in some cases, completely remove the ZPEL. When using sufficiently high values for the damping coefficient, the expected energy distribution among the vibrational modes is ensured. In this case, the QTB method gives very encouraging results. In particular, the structural properties are well-reproduced. The dynamical properties should be regarded with caution although valuable information can still be extracted from the vibrational spectrum, even for large values of the damping term.

show abstract

“…However, the cell is also influenced by quantum vacuum fluctuations (called also zero point energy, ZPE), of which the proposed discrete GMfrequencies are a part of the total spectrum of quantum vacuum oscillations. A relation between coherent states of water molecules and quantum vacuum (ZPE) electromagnetic fields has been proposed (Ganeshan 2013;Sen, 2015). In principle, this field activity can excite all cellular components by resonance.…”

Section: Discussionmentioning

confidence: 99%

Untitled

2020

WATER

View full text Add to dashboard Cite

This paper addresses the question whether electromagnetic frequencies associated with pure water are similar to those of biological systems. A literature survey was performed on intrinsic frequencies of water molecules measured across the electromagnetic spectrum using various spectroscopic technologies. The registered frequencies were plotted on an algorithmic generalized music (GM) scale, described by a quantum entangled wave function, and compared with earlier detected electromagnetic frequency patterns revealed in various biological systems. The meta-analysis shows that semi-harmonic frequency patterns found in purified water are very similar to those found in biological systems. A metaanalysis of about 700 measured frequencies of pure water shows that 192 subsequent first and second derivatives of spectral frequency curves of water molecules can be precisely positioned at the proposed lines of the calculated pattern of coherent eigenfrequencies with an error of 0.45% and statistical significance of p < 0.02. A new order parameter characteristic for water molecule assembly has been revealed, which implies quantum coherency and entanglement. This is in line with the already evidenced and published universal order that we called the GM-scale. Following these findings, we may assume that water molecule assembly shows electromagnetic and electronic collective states that contain "quantum imprints or molds" for living cells. A potential explanation for this feature is that water molecules are ordered in a partially distorted tetrahedral geometry, which yields a specific network structure. Since water molecules have a comparable distribution of coherent electromagnetic field (EMF) bands to that of fluid assemblies in living cells, a resonant wave interaction is expected between the cytoplasm and surrounding water molecules. Evidence of a new quantum wave equation of coherence for water molecules has been found, that is defined as a physical principle: E n = ħ ω ref 2 n+p 3 m .

show abstract

Simulation of quantum zero-point effects in water using a frequency-dependent thermostat

Cited by 16 publications

References 35 publications

Semi-classical generalized Langevin equation for equilibrium and nonequilibrium molecular dynamics simulation

Semi-classical generalized Langevin equation for equilibrium and nonequilibrium molecular dynamics simulation

Zero-Point Energy Leakage in Quantum Thermal Bath Molecular Dynamics Simulations

Untitled

Contact Info

Product

Resources

About