Access particle temperatures before and after run command

Submitted by rich_st on Sun, 04/19/2020 - 09:04

Dear all,

I'm using LIGGGHTS along with a ray tracing code to simulate a particle mixture with radiative heat transfer. For coupling, the LIGGGHTS script is regularly restarted and reads heat source files from the ray tracing code. Particle temperature update is then performed within LIGGGHTS by the run command.
In addition, I want to implement a chemical reaction and therefore need to access the per-particle temperature differences (before vs. after the temperature update). If I, however, define a variable for calculation of this temperature difference, it will be evaluated after the run command only, and therefore will give a value of zero.
Does anybody of you have an idea on how to access the temperatures before and after the run command individually, so that I can properly calculate the temperature difference? A way to evaluate the temperature difference directly would work as well.

Best,
Sebastian

Forums:

rich_st | Sun, 04/19/2020 - 23:20

... the method described in the variable command documentation (Immediate Evaluation of Variables),

variable v equal vol
variable v0 equal $v

doesn't work with atom style variables instead of equal style ones, no matter if I use a 'run 0' or not. Always gives me 'Substitution for illegal variable'

Best,
sebastian

rich_st | Tue, 04/21/2020 - 23:06

Maybe it helps when I reformulate my question:
Is it possible to immediately evaluate the per-atom temperature, e.g. in order to calculate per-atom temperature differences between time steps?
Seems it's not possible to access atom variables by ${...}, so that the method given in the previous post won't work.

rich_st | Wed, 04/22/2020 - 21:56

Whoever has the same problem: fix store/state will do.

Best,
Sebastian