dear Lammps support team,
I am going to compute the component “y” of pairwise distance in a system. I have used compute pair/local and append "dy "as the value, as it is mentioned in the document. However, I get Illegal compute pair/local command. I have even tested it for a two-particle problem and the error still is there.
Could you guide me on what the problem is?
Please always report which LAMMPS version you are using and on which platform you are running.
Also provide a minimal test input deck, if available (like in your case)
Dr. Akohlmey
thank you for your reply and sorry because of my unclear question.
I am using LAMMPS version stable_29Sep2021 on Windows.
Also, this is a simple code that shows what I mean:
echo both
units lj
dimension 3
boundary p p p
atom_style atomic
region simbox block 0 15.0 0 15.0 0 15.0
create_box 1 simbox
create_atoms 1 random 4000 257349 NULL
mass * 1
velocity all create 0.15 492859 dist gaussian rot yes
pair_style lj/cut 2.5
pair_coeff * * 1.0 1.0 2.5
minimize 10e-7 10e-7 100000 100000
thermo_style custom step time
thermo 100
fix 1 all nvt temp 0.15 0.15 1
compute 1 all property/local patom1 patom2
compute 2 all pair/local dy
dump 0 all local 1 pair0.dump index c_1[1] c_1[2] c_2[1]
run 1000
undump 0
unfix 1
Hope this would be clear.
I would be grateful if you guide me.
This version does not support the “dx” option of compute pair/local. It was added after its release (Add ddx, dy and dz computes to compute bond/local and property/local · lammps/lammps@36e4e3e · GitHub).
If you check the local documentation included with your LAMMPS installation, you will see that there is no “dx”, “dy”, or “dz” option documented. Please note that the online documentation always corresponds to the current (stable or development) version.
If you upgrade to the 23 June 2022 stable version, your input will not produce this error (but a different one because your dump command is not correct).
Thank you so much for your help.