Animations from A.
I have placed some non-VRML animations related to my work on
hard-particle packings on this webpage. They are pretty much a random
collection of animations. After a long search for a good movie format
for scientific animations, I discovered the truly wonderful MNG format (like animated GIF
but for PNG):
I use mngplay under Linux and IrfanView for Windows.
On this webpage there are also older animated GIFs and MPEG 2
animations, which should be standard for any system. They are not
nearly as nice as the MNG ones however.
- MD of hard-sphere FCC crystal at phi=0.70 (MPEG) and of hard-sphere
dense liquid at phi=0.49 (MPEG).
Also hard-disk crystal (MPEG)
and hard-disk liquid (MPEG).
- Illustration of the Lubachevsky-Stillinger algorithm for ellipses
(MNG) and for ellipsoids
(MMs!) inside a spherical container (MNG)
and for superellipsoidal cubes (MNG).
- Here is an MRI scan of a real (experimental) ellipsoid packing (MNG).
- Illustration of the use of near-neighbor lists (NNLs) in the MD
- Illustration of the formation of force chains in the jamming
limit for a binary hard-disk packing (MNG).
- Compressing monodisperse disks with a fixed unit cell produces
nearly triangular polycrystalline packings with line deffects (GIF).
Including deformations of the unit cell (Parinello-Rahman-type MD)
leads to perfect triangular packings with some vacancies (GIF).
- Here is an illustration of the working of the free-energy BCMD
algorithm for disks (MNG) and
for ellipses (MNG).
- Illustration of the concept of jamming as configurational
trapping: A disk is locally jammed among three fixed disks (MNG), or it is not
jammed and an unjamming motion exists (MNG).
- A hard-disk packing was produced by freezing some of the disks
(purple). It has a low density phi~0.84 and appears jammed at first
sight. However, running MD reveals that it is not and an unjamming
motion becomes apparent---the new jamming density is closer to phi~0.9 (GIF).
- A collectively jammed disk packing (with rattlers removed) is not
strictly jammed, as apparent when running MD with a deformable unit
cell (lattice vectors) (GIF).
- For ellipsoids the picture is more complicated: This ellipse is
locally jammed, but barely so (MNG).
- A collectively jammed disk packing is stretched to make an
ellipse packing. It is no longer jammed, as MD demonstrates (GIF).
- The strictly jammed triangular disk crystal is stretched to make
an ellipse packing. It is no longer strictly jammed, since it can be
continuously sheared (GIF).
- The density of a random domino tiling is slowly increased from
liquid to jamming: N=5000 (GIF)
and N=1250 (GIF).
- The density of a random domino tiling is slowly reduced from
close packing to liquid densities using MD (GIF).
- A nematic domino tiling changes density from close packing to
Binary hard disks
- Melting of binary phase-separated hard-disk crystal:
At phi=0.775 melting is incomplete (MNG),
at phi=0.763 melting is complete, though slow (MNG)
- For binary hard disks phi~0.8 is the kinetic glass transition
density, and relaxatio dynamics of a supercooled liquid is very slow (MNG),
but at density phi=0.775 the dynamics is liquid-like, with long-time
diffusion and complete mixing (ergodicity?) (MNG).
- Similarly, a partially-clustered (micro-segregated)
nonequilibrium binary disk system at phi=0.8 is stable over long MD
but at a density phi=0.775 it demixes completely (though slowly) (MNG).
- Illustration of the conversion of a partitioning of the
monodisperse triangular crystal into small and large disks into a
binary packing of disks: no clustering (MNG),
medium clustering (MNG), lots
of clustering (MNG).