Local structure analysis in ab initio liquid water

  title={Local structure analysis in ab initio liquid water},
  author={Biswajit Santra and Robert A. Distasio and Fausto Martelli and Roberto Car},
  journal={Molecular Physics},
  pages={2829 - 2841}
Within the framework of density functional theory, the inclusion of exact exchange and non-local van der Waals/dispersion (vdW) interactions is crucial for predicting a microscopic structure of ambient liquid water that quantitatively agrees with experiment. In this work, we have used the local structure index (LSI) order parameter to analyse the local structure in such highly accurate ab initio liquid water. At ambient conditions, the LSI probability distribution, P(I ), was unimodal with most… 

Structural, electronic, and dynamical properties of liquid water by ab initio molecular dynamics based on SCAN functional within the canonical ensemble.

The SCAN functional is generally more accurate than the other two functionals for liquid water by not only capturing the intermediate-range vdW interactions but also mitigating the overly strong hydrogen bonds prescribed in PBE simulations.

Structural, Dynamical, and Electronic Properties of Liquid Water: A Hybrid Functional Study.

Applied to the hydrogen-bond network of liquid water, the dispersion interactions favor more compact structural motifs, bring the density closer to the experimental value, and improve the agreement with experimental observables such as radial distribution functions.

Structure and dynamics of high- and low-density water molecules in the liquid and supercooled regimes

There exists a strong correlation between structural fluctuation and dynamics in the supercooled state with spatial correlations in both static and dynamic quantities, which is linked to structure to dynamics.

Structural features of high-local-density water molecules: Insights from structure indicators based on the translational order between the first two molecular shells.

Molecular dynamics simulations for two water models are employed at the liquid and supercooled regimes combined with the inherent dynamics approach in order to both rationalize the detailed structural and topological information that these indicators provide and to advance in the understanding of the high-density state.

A proposal for the structure of high- and low-density fluctuations in liquid water.

The stability of the proposed dodecahedral template structures is investigated in MD simulations by seeding the starting structure, and remnants found to persist on an ∼30 ps time scale, and the possible significance of such seeds in simulations is discussed.

Correlated Local Fluctuations in the Hydrogen Bond Network of Liquid Water.

The hypothesis that liquid water can separate into two phases in the supercooled state has been supported by recent experimental and theoretical studies. However, whether such structural

Unravelling the contribution of local structures to the anomalies of water: The synergistic action of several factors.

  • F. Martelli
  • Chemistry
    The Journal of chemical physics
  • 2019
The results reveal and rationalize the complex microscopic origin of water's anomalies as the cooperative effect of several factors acting synergistically and beyond implications for water, the findings may be extended to other materials displaying anomalous behaviours.

A Comparison of QM/MM Simulations with and without the Drude Oscillator Model Based on Hydration Free Energies of Simple Solutes

The authors' simulations test the compatibility of quantum-mechanical methods with molecular-mechnical water models and solute Lennard–Jones parameters, and strategies to improve the convergence and efficiency of multi-scale free energy simulations by automatically adapting the molecular- mechanics force field to the target quantum method are discussed.

A Unified Description of the Liquid Structure, Static and Dynamic Anomalies, and Criticality of TIP4P/2005 Water by a Hierarchical Two-State Model.

Water has anomalous thermodynamic and kinetic properties distinct from ordinary liquids. The famous examples are the density maximum at 4 °C and the viscosity decrease upon pressurization. The

The individual and collective effects of exact exchange and dispersion interactions on the ab initio structure of liquid water.

This work found that the collective inclusion of Exx and vdW as resulting from a large-scale AIMD simulation of (H2O)128 significantly softens the structure of ambient liquid water and yields an oxygen-oxygen structure factor, SOO(Q), and corresponding oxygen- oxygengen radial distribution function, gOO(r), that are now in quantitative agreement with the best available experimental data.

Ab initio van der waals interactions in simulations of water alter structure from mainly tetrahedral to high-density-like.

An O-O PCF consisting of a linear combination of 70% from vdW-DF2 and 30% from low-density liquid water, as extrapolated from experiments, reproduces near-quantitatively the experimental O- O PCF for ambient water, suggesting the possibility that the new functionals may be reliable and that instead larger-scale simulations in the NPT ensemble could resolve the apparent discrepancy with the measured PCF.

Isobaric first-principles molecular dynamics of liquid water with nonlocal van der Waals interactions.

This work investigates the structural properties of liquid water at near ambient conditions using first-principles molecular dynamics simulations based on a semilocal density functional augmented with nonlocal van der Waals interactions, finding that the directionality of the hydrogen-bond interaction has a diminished role as compared to the overall attractions.

Van der Waals effects in ab initio water at ambient and supercritical conditions.

It is shown that the semi-empirical correction by Grimme et al. improves significantly, although somewhat counter-intuitively, both the structural and the dynamical description of supercritical water.

Density, structure, and dynamics of water: the effect of van der Waals interactions.

A DFT-AIMD study of liquid water using several GGA functionals as well as the van der Waals density functional (vdW-DF) of Dion et al. finds that the density of water is grossly underestimated by G GA functionals, and when a vdW- DF is used, the density improves drastically and the experimental diffusivity is reproduced without the need of thermal corrections.

Structure and Dynamics of Liquid Water from ab Initio Molecular Dynamics-Comparison of BLYP, PBE, and revPBE Density Functionals with and without van der Waals Corrections.

Results from simulations using GGA density functionals (BLYP, PBE, and revPBE) with data from their van der Waals (vdW) corrected counterparts demonstrate the delicacy needed in describing weak interactions in molecular liquids.

Structure of liquid water at ambient temperature from ab initio molecular dynamics performed in the complete basis set limit.

Compared to recent ab initio MD simulations based on PW basis sets, less significant overstructuring was found in the RDFs and the distributions of hydrogen bond angles, suggesting that previous plane-wave and Gaussian basis set calculations have exaggerated the tendency toward over Structural properties.

Two exchange-correlation functionals compared for first-principles liquid water

The first-principles description of liquid water using ab initio molecular dynamics (AIMD) based on density functional theory (DFT) has recently been found to require long equilibration times, giving

Dynamical properties of liquid water from ab initio molecular dynamics performed in the complete basis set limit.

The relaxation dynamics of hydrogen bonds observed in the present AIMD simulation is slower than those of popular force fields, such as the TIP4P potential, but comparable to that of the Tip5P potential.

On the accuracy of density-functional theory exchange-correlation functionals for H bonds in small water clusters. II. The water hexamer and van der Waals interactions.

It is shown that the addition of an empirical pairwise (attractive) C(6)R(-6) correction to certain functionals allows for an improved energetic ordering of the hexamers, and the relevance of these results to density-functional simulations of liquid water is briefly discussed.