# NVU dynamics. I. Geodesic motion on the constant-potential-energy hypersurface.

@article{Ingebrigtsen2011NVUDI, title={NVU dynamics. I. Geodesic motion on the constant-potential-energy hypersurface.}, author={Trond S Ingebrigtsen and S{\o}ren Toxvaerd and Ole J. Heilmann and Thomas B Schr{\o}der and Jeppe C. Dyre}, journal={The Journal of chemical physics}, year={2011}, volume={135 10}, pages={ 104101 } }

An algorithm is derived for computer simulation of geodesics on the constant-potential-energy hypersurface of a system of N classical particles. First, a basic time-reversible geodesic algorithm is derived by discretizing the geodesic stationarity condition and implementing the constant-potential-energy constraint via standard Lagrangian multipliers. The basic NVU algorithm is tested by single-precision computer simulations of the Lennard-Jones liquid. Excellent numerical stability is obtained…

## 21 Citations

NVU dynamics. II. Comparing to four other dynamics.

- Physics, MedicineThe Journal of chemical physics
- 2011

NVU dynamics is compared to Monte Carlo dynamics, to a diffusive dynamics of small-step random walks on the constant-potential-energy hypersurface, and to Nosé-Hoover NVT dynamics, which show that all five dynamics are equivalent at low temperatures except at short times.

NVU dynamics. III. Simulating molecules at constant potential energy.

- Physics, MedicineThe Journal of chemical physics
- 2012

This paper derives an algorithm for simulating rigid bonds and test this algorithm on three different systems: an asymmetric dumbbell model, Lewis-Wahnström o-terphenyl (OTP) and rigid SPC/E water and shows that NVU dynamics becomes equivalent to NVE dynamics in the thermodynamic limit also for molecular systems.

Energy conservation in molecular dynamics simulations of classical systems.

- Medicine, PhysicsThe Journal of chemical physics
- 2012

Simulations show that inclusion of the first non-trivial term in this expansion of the time step length reduces the standard deviation of the energy fluctuations by a factor of 100 and analytically and numerically shows that energy conservation is not sensitive to round-off errors.

Discrete dynamics versus analytic dynamics.

- Physics, MedicineThe Journal of chemical physics
- 2014

It is proof that there, independent of such an analytic analogy, exists an exact hidden energy invariance E(*) for VA dynamics.

Simplicity of condensed matter at its core: generic definition of a Roskilde-simple system.

- Medicine, PhysicsThe Journal of chemical physics
- 2014

The isomorph theory is reformulated by defining Roskilde-simple systems by the property that the order of the potential energies of configurations at one density is maintained when these are scaled…

The EXP pair-potential system. II. Fluid phase isomorphs.

- Physics, MedicineThe Journal of chemical physics
- 2018

As expected from the exponentially repulsive EXP system's strong virial potential-energy correlations, the reduced-unit structure and dynamics are isomorph invariant to a good approximation.

The EXP pair-potential system. I. Fluid phase isotherms, isochores, and quasiuniversality.

- Physics, MedicineThe Journal of chemical physics
- 2018

A constant-potential-energy (NVU)-based proof of quasiuniversality is presented, and quasiunIVERSality is illustrated by showing that the structure of the Lennard-Jones system at four state points is well approximated by those of EXP pair-potentially systems with the same reduced diffusion constant.

Isomorphs, hidden scale invariance, and quasiuniversality.

- Mathematics, MedicinePhysical review. E, Statistical, nonlinear, and soft matter physics
- 2013

An approximate scaling property of the potential-energy function of a classical liquid with good isomorphs (a Roskilde-simple liquid) is established and this "pseudohomogeneous" property makes explicit that such a system has a hidden scale invariance.

Isomorph theory of physical aging.

- Physics, MedicineThe Journal of chemical physics
- 2018

The proposed theory implies that R-simple glass-forming liquids are characterized by the dynamic Prigogine-Defay ratio being equal to unity, which is in turn implied by the Langevin equation.

Excess-entropy scaling

- 2018

This article gives an overview of excess-entropy scaling, the 1977 discovery by Rosenfeld that entropy determines properties of liquids like viscosity, diffusion constant, and heat conductivity. We…

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NVU dynamics is compared to Monte Carlo dynamics, to a diffusive dynamics of small-step random walks on the constant-potential-energy hypersurface, and to Nosé-Hoover NVT dynamics, which show that all five dynamics are equivalent at low temperatures except at short times.

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