# Is it possible to dump the information of atoms in the same order at each time step, in term of atom ID?

Dear LAMMPS users,

When I calculate the velocity auto-correlation function, I output the velocities of atoms using the command “dump”, e.g. “dump 1 all argon.vel id vx vy vz”. I noticed that the information of the atoms is dumped in different orders at different time step.

For example.

at the first time step , the dump information is something like the following lines,

ITEM: ATOMS id vx vy vz
118 -0.5 -2.19 1.21
564 0.37 -1.46 1.78
404 -2.02 -.55 0.11

The first line is the information of atom whose id is 118. The second line is atom 564, and the third line is atom 404.

at the second time step, the order of sorting the ids is differnet,

ITEM: ATOMS id vx vy vz
118 -0.53 -2.19 1.20
657 0.61 -1.71 -0.54
591 0.74 0.41 -0.13

The first line is still atom 118. But the second line is atom 657, and the third line is atom 591. The order in which the

My question is that whether it is possible to dump the information of atoms in the same order in terms of ID at each time step. Thanks.

Bests,

Han Hu

Complex Fluids and Multiphase Transport Lab
Mechanical Engineering and Mechanics Department
Drexel University
Hess Engineering Research Laboratories
hh398@…1685…, edenkira@…92…

Dear LAMMPS users,

When I calculate the velocity auto-correlation function, I output the
velocities of atoms using the command "dump", e.g. "dump 1 all argon.vel id
vx vy vz". I noticed that the information of the atoms is dumped in
different orders at different time step.

For example.

at the first time step , the dump information is something like the
following lines,

ITEM: ATOMS id vx vy vz
118 -0.5 -2.19 1.21
564 0.37 -1.46 1.78
404 -2.02 -.55 0.11
......

The first line is the information of atom whose id is 118. The second line
is atom 564, and the third line is atom 404.

at the second time step, the order of sorting the ids is differnet,

ITEM: ATOMS id vx vy vz
118 -0.53 -2.19 1.20
657 0.61 -1.71 -0.54
591 0.74 0.41 -0.13
......

The first line is still atom 118. But the second line is atom 657, and the
third line is atom 591. The order in which the

My question is that whether it is possible to dump the information of atoms
in the same order in terms of ID at each time step. Thanks.

yes!

this is explained right in the first paragraph

please spend at least a little effort on looking
"how can i do" type of questions.

thanks,
axel.

Dear Axel,

Thanks very much.

Bests,

Han Hu

Here's another option, from the pizza.py toolkit.

http://pizza.sandia.gov/doc/dump.html

v/r,

dc