Unused restart file global fix info

Hello Everyone
I am facing a strange error while reading the restart info from the output of. an NPT run to run an NVT simulation. the calculation paused with the error
“Reading potential file /usr/local/Cellar/lammps/20220623/share/lammps/potentials/SiC.edip with DATE: 2017-05-16
Unused restart file global fix info:
fix style: npt, fix ID: 1”

i couldn’t find the info about it in the lammps documentation, can anyone suggest what could be the reason of this error
here is my input

‘’

velocity all create 2000.0 87287 rot yes dist gaussian loop geom
#giving atominc interactions
newton on on
pair_style edip/multi
pair_coeff * * /usr/local/Cellar/lammps/20220623/share/lammps/potentials/SiC.edip Si C

#NPT runs
fix 1 all npt temp 2000.0 2000.0 $(1000.0*dt) iso 1.0 1.0 100
timestep 0.001
thermo 500
#log log.nptvc.2000.puresic
#dump npt all atom 5000 dump.cvacnpt.2000
run 1000
write_restart restart.nptvc.2000

clear
#NVT run
read_restart restart.nptvc.2000
change_box all x final 0 26.5806
change_box all y final 0 26.58066
change_box all z final 0 26.58066
newton on on
pair_style edip/multi
pair_coeff * * /usr/local/Cellar/lammps/20220623/share/lammps/potentials/SiC.edip Si C
fix 2 all nvt temp 2000.0 2000.0 $(120.0*dt)
compute 1 all orientorder/atom nnn 4 cutoff 2.8
compute coord all coord/atom orientorder 1 0.5
timestep 0.001
#thermo_style custom step temp c_coord
thermo 500
log log.nvtvc.2000
dump nvt all custom 5000 dump.cvacnvt.2000 id type x y z c_coord
run 1000000 ’
I will highly appreicate your response
KR Irslan Ullah Ashraf

This is not an error.
Information about this is here: read_restart command — LAMMPS documentation

In your first run (from which you create a binary restart file), you have fix npt with fix-ID 1.
Fix npt supports writing the state of the nose-hoover chains to restart files, so that data is included.

In your second run (where you read the restart file) is no fix npt and no fix with fix-ID 1, hence the data from fix npt is read from the restart file, but not used. Hence the message.

1 Like

Dear Dr. Akohlmey
thanks for encouraging comment, I see this message is not an error but my calculation stops with the message and don’t just finishes, even i have made the ID same for both fixes, and also change the IDs of computes there is still the same problem
however the calculation continues without any message if i turn of the computes, I just can’t understand what is happening , here is my input

newton on on
pair_style              edip/multi
pair_coeff              * * /usr/local/Cellar/lammps/20220623/share/lammps/potentials/SiC.edip Si C

#NPT runs
fix             1 all npt temp 2000.0 2000.0 $(1000.0*dt) iso 1.0 1.0 100 
timestep        0.001
thermo          500
#log            log.nptvc.2000.puresic
#dump           npt all atom 5000 dump.cvacnpt.2000
run             1000
write_restart   restart.nptvc.2000
clear
#NVT run
read_restart    restart.nptvc.2000
change_box all x final 0 26.5806
change_box all y final 0 26.58066
change_box all z final 0 26.58066
velocity        all create 2000.0 87287 rot yes dist gaussian loop geom
newton on on
pair_style      edip/multi
pair_coeff      * * /usr/local/Cellar/lammps/20220623/share/lammps/potentials/SiC.edip Si C
#fix             1 all npt temp 2000.0 2000.0 $(1000.0*dt) iso 1.0 1.0 100
#unfix          1
fix             1 all nvt temp 2000.0 2000.0  $(120.0*dt)
compute         order all orientorder/atom nnn 4 cutoff 2.8
compute         coord all coord/atom orientorder order 0.5
thermo          500
log             log.nvtvc.2000
dump            nvt all custom 5000 dump.cvacnvt.2000 id type x y z c_coord
run             10000

please accept my best regards
Irslan Ullah Ashraf

I don’t have a crystal ball, so it is impossible to understand what goes wrong from remote.
If you want somebody to take a closer look you have to:

  1. produce a small and complete input deck that can easily and quickly reproduce the issue
  2. check that the issue is still present with the latest LAMMPS feature release (8 Feb 2023). If you are on a Linux machine and don’t want to compile the new version, you can get a binary from here: LAMMPS Static Linux Binary Download Repository: .
1 Like

Thank you so much your suggestion(2) worked perfectly to fix my problem.
Please accept my best Regards