# Out of range

Hi, dear Users,
I am a new lammps user and recently I want to simulate strain experiment about PETG. After 300000 time equilibrium I began to stretch the chains. Funny is, I use same tension.in fiel for pure PETG, PETG+water, PETG+ethanol and PETG+methanol. It is work for pure PETG and PETG+water, but by the other here shows an error: ERROR on proc 264: Out of range atoms - cannot compute PPPM (src/KSPACE/pppm.cpp:1945)

I have tried with faster and slower rate but it didnt work.
Here is my tension.in

# LAMMPS atomistic input script

echo screen

units real

atom_style full

pair_style lj/class2/coul/long 9.5 9.5

bond_style class2

angle_style class2

dihedral_style class2

improper_style class2

pair_modify mix sixthpower tail yes

special_bonds lj/coul 0 0 1

# Integration conditions (check)

timestep 0.5

kspace_style pppm 1e-5

fix mom all momentum 100 linear 1 1 1 angular

#--------------- Variables Definition---------

thermo 1000

thermo_style custom step dt temp vol density etotal ke lx ly lz press pxx pyy pzz pe evdwl ecoul ebond eangle edihed eimp

variable temp index 300

variable tmp equal “lx”

variable L0 equal \${temp}

variable srate equal “1.0e-5” # change it from 5-7

variable srate1 equal “v_srate”

variable strain equal “(lx-v_L0)/v_L0”

variable p1 equal “v_strain”

variable p2 equal “-pxx/10000*1.01325”

variable p3 equal “-pyy/10000*1.0132”

variable p4 equal “-pzz/10000*1.0132”

variable p5 equal “lx”

variable p6 equal “ly”

variable p7 equal “lz”

variable p8 equal “press”

variable p9 equal “pxy”

variable p10 equal “pxz”

variable p11 equal “pyz”

variable step equal step

variable dt equal dt

variable vol equal vol

variable dens equal density

variable etotal equal etotal

variable ke equal ke

variable pe equal pe

variable tmp equal “lx”

variable L0 equal \${temp}

variable srate equal “1.0e-5” # change it from 5-7

variable srate1 equal “v_srate”

variable strain equal “(lx-v_L0)/v_L0”

variable p1 equal “v_strain”

variable p2 equal “-pxx/10000*1.01325”

variable p3 equal “-pyy/10000*1.0132”

variable p4 equal “-pzz/10000*1.0132”

variable p5 equal “lx”

variable p6 equal “ly”

variable p7 equal “lz”

variable p8 equal “press”

variable p9 equal “pxy”

variable p10 equal “pxz”

variable p11 equal “pyz”

variable step equal step

variable dt equal dt

variable vol equal vol

variable dens equal density

variable etotal equal etotal

variable ke equal ke

variable pe equal pe

variable evdwl equal evdwl

variable ecoul equal ecoul

variable ebond equal ebond

variable eangle equal eangle

variable edihed equal edihed

variable eimp equal eimp

#--------------- Deformation ------------------

reset_timestep 0

timestep 0.5

fix 1 all npt temp 300 300 50 y 0 0 500 z 0 0 500 nreset 1000

fix 2 all deform 1 x trate \${srate1} units box remap x

fix def1 all print 1000 “{step} {dt} {temp} {vol} {dens} {etotal} {ke} {pe} {evdwl} {ecoul} {ebond} {eangle} {edihed} \${eimp}” file energies_npt.dat screen no title “step dt temp vol density etotal ke pe evdwl ecoul ebond eangle edihed eimp”

fix def2 all print 1000 “{step} {dt} {temp} {vol} {etotal} {p1} {p2} {p3} {p4} {p5} {p6} {p7} {p8} {p9} {p10} {p11}” file tension_npt.dat screen no title “step dt temp vol p1 p2 p3 p4 p5 p6 p7 p8 p9 p10 p11”

dump 1 all cfg 10000 dump.tensile_* mass type xs ys zs fx fy fz id q mol

dump_modify 1 element o_2 ho2 oh c hc c1 c_1 o_1 cp ho

run 200000

write_data tension.data

print “ALL DONE!”

Thanks for your help!
Best regards

Hi, dear Users,
I am a new lammps user and recently I want to simulate strain experiment about PETG. After 300000 time equilibrium I began to stretch the chains. Funny is, I use same tension.in fiel for pure PETG, PETG+water, PETG+ethanol and PETG+methanol. It is work for pure PETG and PETG+water, but by the other here shows an error: ERROR on proc 264: Out of range atoms - cannot compute PPPM (src/KSPACE/pppm.cpp:1945)
I have tried with faster and slower rate but it didnt work.

it is difficult to say anything without seeing output, knowing more
details about the starting geometry, size of system, how well the
system is equilibrated, command line, LAMMPS version, and more.

two more possibilities to consider:
- reduce the time step. 0.5 is very aggressive for systems with
unconstrained bonds to hydrogen atoms
- you seem to be using a lot of MPI ranks, try (much) less. unless you
have a massively large system, you actually may be running faster with
less processors, anyway. when you "overparallelize" pppm it will
become very slow. check your output from equilibration. how is the
distribution of time spent between the different sections in the
summary report at the end of the log file?

if these (wild?) guesses don't help, you will need to provide more
details as listed above and best try if you can reproduce the issue
with a tiny system (say 30000 atoms or less) and post a corresponding
working and not working system input and data file here.

axel.