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Related papers: An optimized molecular model for ammonia

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The so-called thermodynamic anomalies of water form an integral part of the peculiar behaviour of this both important and ubiquitous molecule. In this paper our aim is to establish whether the recently proposed TIP4P/2005 model is capable…

We demonstrate a novel experimental technique for quantum-state tomography of the collective density matrix. It is based on measurements of the polarization of light, traversing the atomic vapor. To assess the technique's robustness against…

Quantum Physics · Physics 2025-08-29 Marek Kopciuch , Magdalena Smolis , Adam Miranowicz , Szymon Pustelny

A major challenge for molecular modeling consists in optimizing the unlike interaction potentials. In many cases, combination rules are generally suboptimal when accurate predictions of properties like the mixture vapor pressure are needed.…

Computational Physics · Physics 2010-01-13 Martin Horsch , Martina Heitzig , Thorsten Merker , Thorsten Schnabel , Yow-Lin Huang , Hans Hasse , Jadran Vrabec

Even though the phenomenon of evaporation is omnipresent and has immense scientific and technological importance, the research effort to unveil its fundamentals remains inadequately low. As one particular consequence, the textbooks and…

Other Condensed Matter · Physics 2014-06-10 V. V. Semak

Simulating the dynamics of ions near polarizable nanoparticles (NPs) using coarse-grained models is extremely challenging due to the need to solve the Poisson equation at every simulation timestep. Recently, a molecular dynamics (MD) method…

Computational Physics · Physics 2019-11-01 JCS Kadupitiya , Geoffrey C. Fox , Vikram Jadhao

While molecular dynamics (MD) is a very useful computational method for atomistic simulations, modeling the interatomic interactions for reliable MD simulations of real materials has been a long-standing challenge. In 2007, Behler and…

Materials Science · Physics 2025-06-11 Ling Tang , Weiyi Xia , Gayatri Viswanathan , Ernesto Soto , Kirill Kovnir , Cai-Zhuang Wang

Building upon recent developments of force-based estimators with a reduced variance for the computation of densities, radial distribution functions or local transport properties from molecular simulations, we show that the variance can be…

Chemical Physics · Physics 2021-05-18 Samuel W. Coles , Etienne Mangaud , Daan Frenkel , Benjamin Rotenberg

Nucleation in supersaturated vapor is investigated with two series of molecular dynamics simulations in the canonical ensemble. The applied methods are: (a) analysis of critical nuclei at moderate supersaturations by simulating equilibria…

Chemical Physics · Physics 2009-11-13 Martin Horsch , Jadran Vrabec , Hans Hasse

Data-driven prediction of molecular properties presents unique challenges to the design of machine learning methods concerning data structure/dimensionality, symmetry adaption, and confidence management. In this paper, we present a…

Machine Learning · Computer Science 2019-01-31 Yu-Hang Tang , Wibe A. de Jong

Results of a systematic investigation of the vapour-liquid equilibria of 38 individual two-centre Lennard-Jones plus axial pointdipole model fluids (2CLJD) are reported over a range of reduced dipolar momentum 0 $\le \mu^{*2} \le$ 20 and of…

Computational Physics · Physics 2009-04-23 Jürgen Stoll , Jadran Vrabec , Hans Hasse

Calculating sublimation enthalpies of molecular crystal polymorphs is relevant to a wide range of technological applications. However, predicting these quantities at first-principles accuracy -- even with the aid of machine learning…

Predicting the physico-chemical properties of pure substances and mixtures is a central task in thermodynamics. Established prediction methods range from fully physics-based ab-initio calculations, which are only feasible for very simple…

Machine Learning · Computer Science 2024-12-02 Johannes Zenn , Dominik Gond , Fabian Jirasek , Robert Bamler

In studying solidification process by simulations on the atomic scale, the modeling of crystal nucleation or amorphisation requires the construction of interatomic interactions that are able to reproduce the properties of both the solid and…

A new molecular simulation method for the calculation of vapour-liquid equilibria of mixtures is presented. In this method, the independent thermodynamic variables are temperature and liquid composition. In the first step, one isobaric…

Chemical Physics · Physics 2009-05-06 J. Vrabec , H. Hasse

Numerous accidental near-degeneracies exist between the $2\nu_2$ and $\nu_4$ rotation-vibration energy levels of ammonia. Transitions between these two states possess significantly enhanced sensitivity to a possible variation of the…

Chemical Physics · Physics 2018-08-17 Alec Owens , Sergei N. Yurchenko , Walter Thiel , Vladimir Špirko

We develop a maximum relative entropy formalism to generate optimal approximations to probability distributions. The central results consist in (a) justifying the use of relative entropy as the uniquely natural criterion to select a…

Statistical Mechanics · Physics 2008-10-17 Chih-Yuan Tseng , Ariel Caticha

A model potential previously developed for the ammonia molecule is treated in a single-center partial-wave approximation in analogy with a self-consistent field method developed by Moccia. The latter was used in a number of collision…

Chemical Physics · Physics 2024-04-17 Patrik Pirkola , Marko Horbatsch

Transport properties of liquid methanol and ethanol are predicted by molecular dynamics simulation. The molecular models for the alcohols are rigid, non-polarizable and of united-atom type. They were developed in preceding work using…

Chemical Physics · Physics 2009-06-10 Gabriela Guevara-Carrion , Carlos Nieto-Draghi , Jadran Vrabec , Hans Hasse

We apply to a liquid of linear molecules the semischematic mode-coupling model, previously introduced to describe the center of mass (COM) slow dynamics of a network-forming molecular liquid. We compare the theoretical predictions and…

Soft Condensed Matter · Physics 2009-10-31 Linda Fabbian , Rolf Schilling , Francesco Sciortino , Piero Tartaglia , Christoph Theis

We present experiments in which an ultra-cold sample of ammonia molecules is released from an electrostatic trap and recaptured after a variable time. It is shown that, by performing adiabatic cooling before releasing the molecules and…

Chemical Physics · Physics 2015-06-19 Marina Quintero-Pérez , Thomas E. Wall , Steven Hoekstra , Hendrick L. Bethlem