compute property/atom command with multisphere

I find that the compute property/atom command dose not work with multisphere, it cant give the force on each atom(fx fy fz). It always be 0 0 0. I guess there should be a restriction along with the compute property/atom command. And I wonder how to get the resultant force on each multisphere body on each time-step.

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LIGGGHTS® - User Forum

richti83 | Fri, 12/18/2015 - 08:02

compute rigid

That's right. The premium version of LIGGGHTS(R) contains an additional "compute rigid" which can access the internal properties of multispheres (center of mass, force on center of mass, quaternion, id, type) but unfortunately this file did'n get into public. Maybe Christoph decides to give the compute free as christmas gift, otherwise you'll need to write it on your own. (hint: have a look at the basic properties in multisphere.h /cpp and how to access them)

zhou_yu | Fri, 12/18/2015 - 14:37

Thanks for your reply and I

Thanks for your reply and I finally know why the compute multisphere command does not work. The online documentation does not give any hint that this command cant be used in lingghts-public.

richti83 | Fri, 12/18/2015 - 21:15

Interesting, I didn't noticed

Interesting, I didn't noticed the compute is allready in the doc but not in the source - This give us hope that it has been only forgotten and we can hope for a 3.3.0 Christmas Edition with compute multisphere included. I can than provide a workflow how to make such cool clump-animations:
https://youtu.be/iC5OZtnLc8Y
(needs xcm & quat as local dump and a little python scripting :-))

ckloss | Tue, 12/22/2015 - 19:55

Hi all,

yes the compute rigid was unintentionally left out and will actually be included in the next PUBLIC release in Jan 16!

Best wishes and happy holidays,
Christoph