Ellipsoids and angular velocity

LAMMPS LAMMPS Beginners
1

hello all,

for a class project i am attempting to simulate ellipsoid-shaped particles exhibiting brownian motion (using fix langevin). i can visually see the fluctuations and changes in its velocity by dumping its velocities and visualizing them in OVITO (ovito has an option to show them as arrows).

however, i also want to see the changes in its rotation (angular velocity) represented by arrows as well (i do not know if it is possible, or if there is a better way of visualizing angular velocity). upon looking around, i cannot dump omegax omegay omegaz (angular velocities) since my atom_style is ellipsoid. i have tried dumping angmomx angmomy angmomz instead and then using OVITO Basic’s compute property but i am unable to make it work.

i apologize if this question has been asked and answered already, or if this may seem to obvious and is a dumb question. i am not quite well-versed in the technicality of lammps and ovito so any guidance would be very much appreciated.

thank you!

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This sounds more like a question for the Ovito matsci forum, but I was able to use the compute property modifier to map the angular momenta to another vector quantity that generates arrows (e.g. velocities, displacements). A bit hacky, but it works.

Depending on your framerate, you could also explicitly visualize rotation by dumping quaternions in LAMMPS using compute property/atom to rotate actual ellipsoidal particles in Ovito.

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