npt thermostat in conjugation with compute

Dear LAMMPS users,

I am trying to simulate LaMnO3 using core shell potential. I am trying to write the “FIX NPT” command in conjugation with the “compute ID all temp/cs cores shells” command. I am getting the following error. The input Script and the error text is given below. The initial structure file is attached.

Please help me to find out where I am committing mistake.

With Regards

Omkar

#------------------------INITIALIZATION----------------------------

units metal
dimension 3
boundary p p p
atom_style full

#-----------------------ATOM DEFINITION----------------------------

#fix csinfo all property/atom i_CSID
read_data inp.xyz # fix csinfo NULL CS-Info

group cores type 1 2 3
group shells type 4 5 6

neighbor 2.0 bin
comm_modify vel yes

------------------------FORCE FIELDS------------------------------

kspace_style ewald 1.0e-6
pair_style buck/coul/long/cs 11.0 # A, rho, sigma=0, C, D

pair_coeff * * 0.0 1.0 0.0

pair_coeff 4 6 1545.21 0.3590 0.0 #La-O

pair_coeff 5 6 1267.50 0.3214 0.0 #Sr-O

pair_coeff 6 6 22764.3 0.1490 43.0 #O-O

bond_style harmonic
bond_coeff 1 145.0 0.0
bond_coeff 2 95.0 0.0
bond_coeff 3 42.0 0.0

------------------------ Equilibration Run -------------------------------

reset_timestep 0

thermo 100
thermo_style custom step temp pe etotal press vol cella cellb cellc cellalpha cellbeta cellgamma

compute CSequ all temp/cs cores shells
compute CSpress all pressure CSequ

thermo_modify temp CSequ

velocity bias option

velocity all create 1427 134 dist gaussian mom yes rot no bias yes temp CSequ
velocity all scale 1427 temp CSequ

fix 1 all npt 1427.0 1427.0 0.1 iso 0.0 0.0 1.0

fix_modify 1 temp CSequ press CSpress

1 fmsec timestep

timestep 0.001
run 10000

------------------------ Dynamic Run -------------------------------

dump 1 all custom 100 Trajectory id xu yu zu vx vy vz

run 10000

--------------Output--------------

LAMMPS (16 Feb 2016)
Reading data file …
orthogonal box = (0 0 0) to (31.232 31.232 31.232)
2 by 2 by 4 MPI processor grid
reading atoms …
5120 atoms
scanning bonds …
1 = max bonds/atom
reading bonds …
2560 bonds
Finding 1-2 1-3 1-4 neighbors …
Special bond factors lj: 0 0 0
Special bond factors coul: 0 0 0
1 = max # of 1-2 neighbors
0 = max # of 1-3 neighbors
0 = max # of 1-4 neighbors
1 = max # of special neighbors
2560 atoms in group cores
2560 atoms in group shells
Ewald initialization …
G vector (1/distance) = 0.336075
estimated absolute RMS force accuracy = 1.83544e-05
estimated relative force accuracy = 1.27465e-06
KSpace vectors: actual max1d max3d = 4585 13 9841
kxmax kymax kzmax = 13 13 13
Neighbor list info …
1 neighbor list requests
update every 1 steps, delay 10 steps, check yes
max neighbors/atom: 2000, page size: 100000
master list distance cutoff = 13
ghost atom cutoff = 13
binsize = 6.5, bins = 5 5 5
ERROR: Illegal fix nvt/npt/nph command (…/fix_nh.cpp:336)

inp.xyz (433 KB)

Dear LAMMPS users,

I am trying to simulate LaMnO3 using core shell potential. I am trying to
write the "FIX NPT" command in conjugation with the "compute ID all temp/cs
cores shells" command. I am getting the following error. The input Script
and the error text is given below. The initial structure file is attached.

Please help me to find out where I am committing mistake.

just look at the error message:

ERROR: Illegal fix nvt/npt/nph command (../fix_nh.cpp:336)

that says it all.

please also consult: http://lammps.sandia.gov/doc/Section_errors.html

in order to learn how to better deal with (simple/obvious) errors
(like this one) and figure out a solution by yourself.

axel.