Unknown Identifier Error using restricted triclinic simulation box

I encountered unknown identifier error while running LAMMPS. I am using restricted triclinic simulation box for my simulation. This error mostly likely comes from my data file, but I cannot figure out what went wrong. The lammps version that I used is 2Aug2023, and I am running everything on the perlmutter.

Error Message:

LAMMPS (2 Aug 2023 - Update 3)
KOKKOS mode with Kokkos version 3.7.2 is enabled (src/KOKKOS/kokkos.cpp:108)
  will use up to 1 GPU(s) per node
WARNING: When using a single thread, the Kokkos Serial backend (i.e. Makefile.kokkos_mpi_only) gives better per>
  using 1 OpenMP thread(s) per MPI task
Reading data file ...
  triclinic box = (0 0 0) to (67.882202 58.787711 27.712799) with tilt (-33 0 0)
WARNING: Triclinic box skew is large. LAMMPS will run inefficiently. (src/domain.cpp:220)
  1 by 1 by 1 MPI processor grid
  reading atoms ...
  0 atoms
ERROR: Unknown identifier in data file: 1 1 1 1.3473 0.0000000000 0.0000000000 0.0000000000
For more information see https://docs.lammps.org/err0001 (src/read_data.cpp:929)
Last command: read_data updated_final_ultimate.data
srun: error: nid001816: task 0: Exited with exit code 1
srun: Terminating StepId=30899182.0

Input File:

units     metal
atom_style full

boundary p p p
kspace_style pppm 1.0e-4
pair_style hybrid/overlay  lj/cut/coul/long 8.0 8.0 bv 2.0 8.0 bvv 2.0 8.0
read_data updated_final_ultimate.data

#read_restart BTO.restart
pair_coeff 1 1 lj/cut/coul/long 2.0  2.44805
pair_coeff 1 2 lj/cut/coul/long 2.0  2.32592
pair_coeff 1 3 lj/cut/coul/long 2.0  1.98792
pair_coeff 2 2 lj/cut/coul/long 2.0  2.73825
pair_coeff 2 3 lj/cut/coul/long 2.0  1.37741
pair_coeff 3 3 lj/cut/coul/long 2.0  1.99269


#                   r0   Nij    S     v0 rcut
pair_coeff 1 1 bv 0.0000000 5.0000000 0.5973900 2.0000000 8.0000000
pair_coeff 1 2 bv 0.0000000 5.0000000 0.0000000 0.0000000 8.0000000
pair_coeff 1 3 bv 2.2900000 8.9400000 0.0000000 0.0000000 8.0000000
pair_coeff 2 2 bv 0.0000000 5.0000000 0.1653300 4.0000000 8.0000000
pair_coeff 2 3 bv 1.7980000 5.2000000 0.0000000 0.0000000 8.0000000
pair_coeff 3 3 bv 0.0000000 5.0000000 0.9306300 2.0000000 8.0000000


#                    r0  Nij     S     Bvv0  rcut
pair_coeff 1 1 bvv 0.0000000 5.0000000 0.0842900 0.1156100 8.0000000
pair_coeff 1 2 bvv 0.0000000 5.0000000 0.0000000 0.0000000 8.0000000
pair_coeff 1 3 bvv 2.1430000 8.9400000 0.0000000 0.0000000 8.0000000
pair_coeff 2 2 bvv 0.0000000 5.0000000 0.8248400 0.3943700 8.0000000
pair_coeff 2 3 bvv 1.7980000 5.2000000 0.0000000 0.0000000 8.0000000
pair_coeff 3 3 bvv 0.0000000 5.0000000 0.2800600 0.3165100 8.0000000

neighbor    2.0 bin
neigh_modify    delay 0 every 1000000 check no

# time unit ps
timestep     400

# Define computes for pair energy contributions
compute pairEnergy1 all pair lj/cut/coul/long
compute pairEnergy2 all pair bv
compute pairEnergy3 all pair bvv

thermo     100
thermo_style custom step temp c_pairEnergy1 c_pairEnergy2 c_pairEnergy3 eangle etotal press vol lx ly lz

thermo_modify line one format float %12.5f

#to equilibrate the system at a constant temperature using the NVT ensemble
fix 1 all nvt temp 1.0 1.0 1.0
run 25
unfix 1

fix 2 all nvt temp 1.0 1.0 1.0
dump 2 all custom 200 dump.xyz xyz
dump_modify 2 sort id
run 125
unfix 2

First few lines of Data files:

8640 atoms
3 atom types

0.0 67.882202000000007 xlo xhi
0.0 58.787711396826843 ylo yhi
0.0 27.712799 zlo zhi
   -33.941100999999989 0 0 xy xz yz

Masses

1 137.327  #Ba
3 47.867   #Ti
2 15.999   #O

Atoms

1 1 1 1.3473 0.0000000000 0.0000000000 0.0000000000
2 1 1 1.3473 0.0000000000 0.0000000000 6.9281997500
3 1 1 1.3473 0.0000000000 0.0000000000 13.8563995000
4 1 1 1.3473 0.0000000000 0.0000000000 20.7845992500
5 1 1 1.3473 -2.8284250833 4.8989759497 0.0000000000
6 1 1 1.3473 -2.8284250833 4.8989759497 6.9281997500

Thank you very much!

From the content you provide it looks like your data file is missing the “title” line. If my guess is correct, then LAMMPS will ignore the 8640 atoms atoms line and thus assume your system has 0 (no!) atoms. That is consistent with throwing an error of the first line in the Atom section.

1 Like

Thank you. I will try that out.