Molecular dynamics study of the alloy (N2)67(Ar)29

1985 ◽  
Vol 63 (10) ◽  
pp. 1270-1273 ◽  
Author(s):  
Shuichi Nosé ◽  
Michael L. Klein
Keyword(s):  
Molecular Dynamics ◽  
Low Temperature ◽  
Angular Velocity ◽  
Power Spectrum ◽  
Structural Transition ◽  
Rotational Diffusion ◽  
Velocity Autocorrelation Function ◽  
Reorientational Motion ◽  
Velocity Autocorrelation ◽  
Molecular Dynamics Calculations

Molecular dynamics calculations are used to investigate the effect of isobaric cooling on the hexagonal alloy (N2)67(Ar)29. Particular attention is given to the behavior of the reorientational motion of the N2 molecules. No orientational or structural transition was found to accompany the cooling from 60 to 10 K at either P = 4 × 103 or P = 1 × 103 bar (1 bar = 100 kPa). However, the power spectrum of the angular-velocity autocorrelation function clearly reveals the freezing out of rotational diffusion at low temperature.

Structural and Dynamical Properties of Nanocrystalline Krypton

1997 ◽  
Vol 11 (15) ◽  
pp. 681-690
Author(s):  
N. S. Athanasiou
Keyword(s):  
Molecular Dynamics ◽  
Pair Potential ◽  
Velocity Autocorrelation Function ◽  
Low Frequencies ◽  
Velocity Autocorrelation ◽  
Molecular Dynamics Calculations ◽  
Cluster Properties ◽  
Dynamical Properties ◽  
Nano Cluster ◽  
Number Of Particles

In this paper we discuss structural and dynamical properties of nano-clusters. The study is based on molecular dynamics calculations. In particular, the behavior of the following functions have been studied: single-particle distribution function, velocity autocorrelation function and the generalized phonon density of states (PDOS). The calculations have been done for krypton since for this material a realistic pair potential is available (Barker et al. potential). In order to have more informations about the nano-cluster properties, we also performed molecular dynamics calculations for the bulk. The comparison of the bulk results with the nano-cluster results shows that the shift of the cluster PDOS to low frequencies, caused from the different number of particles.

scholarly journals Velocity autocorrelation function and self-diffusion coefficient in large molecular dynamics models of liquid argon and water

2021 ◽  
Vol 13 (2) ◽  
pp. 149-156
Author(s):  
Yuri I. Naberukhin ◽  
◽  
Alexey V. Anikeenko ◽  
Vladimir P. Voloshin ◽  
◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Diffusion Coefficient ◽  
Autocorrelation Function ◽  
Liquid Argon ◽  
Time Interval ◽  
Velocity Autocorrelation Function ◽  
Self Diffusion ◽  
Velocity Autocorrelation ◽  
The Difference ◽  
Self Diffusion Coefficient

Autocorrelation function of the particle velocity Z(t) is calculated using the molecular dynamics method in the models of liquid argon and water. The large size of the models (more than a hundred thousand particles) allowed us to trace these functions up to 50 picoseconds in argon and up to 10 picoseconds in water, and to achieve a calculation accuracy sufficient for analytical analysis of their shape. The difference in the determination of the self-diffusion coefficient using Einstein's law and the integral of Z(t) (Green-Kubo integral) is analyzed and it is shown to be 3% at best when t is of the order of several picoseconds. The asymptote of the function Z(t) in argon is close to the power law αt–3/2 predicted by hydrodynamics, but with an amplitude that depends on the time interval under consideration. In water, the asymptote of Z(t) has nothing in common with that in argon: it has α < 0 and the exponent is close to -5/2, and not to -3/2.

Molecular Dynamics Study of Structural Transitions and Melting in Two Dimensions

1995 ◽  
Vol 408 ◽  
Author(s):  
L. L. Boyer
Keyword(s):  
Molecular Dynamics ◽  
Low Temperatures ◽  
Structural Transition ◽  
Lattice Strain ◽  
Hexagonal Lattice ◽  
Two Dimensions ◽  
Square Lattice ◽  
Pair Potentials ◽  
Molecular Dynamics Calculations ◽  
Simple Pair

AbstractSimple pair potentials are constructed which give hexagonal- or squarelattice ground states in two dimensions, depending on the value of a single parameter controlling the width of the potential well. Molecular dynamics calculations for free clusters of a few hundred particles are used to examine a structural transition from the square lattice, at low temperatures, to the hexagonal lattice at high temperatures. Another structural transition (melting) is identified by the onset of diffusion. The melting temperature is found to be a minimum near the point where the barrier between the two structures, as a function of lattice strain, is also a minimum.

Sign in / Sign up

Export Citation Format

Share Document