Unable to print values with fix print with values from compute property/atom

LAMMPS LAMMPS General Discussion
1

Hey everyone I have been trying to run this in my input script:
The simulation consists of a polymer containing 400 atoms. I am trying to print the coordinates of the 50th atom to output with the fix print command

compute tr poly property/atom x y z
variable x50 equal c_tr[50][1]
variable y50 equal c_tr[50][2] 
variable z50 equal c_tr[50][3]
fix tr1 poly print 1000 "${x50} ${y50} ${z50}" append xyz_50.txt screen no

However this portion of the code always returns this error when executing:

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image1198×64 24.3 KB

Is there a way to bypass this? I am able to print compute values stored in other variables in the input script but it always fails for the compute property/atom command

2

This is not a valid syntax. c_xxx[i1][i2] is for accessing values from global arrays and not per-atom arrays. Those references have to use a capital C, i.e. C_xx[i1][i2].
This is documented behavior.