Dear Users,

I have come across an error during simulation of a system of gas hydrates.

ERROR:Out of range atoms - cannot compute PPPM (…/pppm_tip4p.cpp:107).

I tried to simulate gas hydrates for 10 nano seconds using 2femto seconds as time step and a thermostat of 1 picoseconds. i am now being unable to know whats the problem at 292840 time step. Will the neigh_modify command be sufficient to troubleshoot the problem Or do i need some changes in the parameters used such as pair coefficients, bond coefficients, angle coefficients, etc

I attach below the log file, input script as well as the data file used.

Seeking an early reply.

Thanks and regards,

Sushree Sucharita

M.Tech., Climate science and Technology

IIT Bhubaneswar

inputonemolecule1.txt

log.lammps

testa.txt

Dear Users,

I have come across an error during simulation of a system of gas hydrates.

ERROR:Out of range atoms - cannot compute PPPM (…/pppm_tip4p.cpp:107).

I tried to simulate gas hydrates for 10 nano seconds using 2femto seconds as time step and a thermostat of 1 picoseconds. i am now being unable to know whats the problem at 292840 time step. Will the neigh_modify command be sufficient to troubleshoot the problem Or do i need some changes in the parameters used such as pair coefficients, bond coefficients, angle coefficients, etc

please look at your log file and you should see multiple things that are troubling from the very beginning:

fix fShakebond water shake 0.0001 100 0 b 1 a 1

0 = # of size 2 clusters

0 = # of size 3 clusters

0 = # of size 4 clusters

0 = # of frozen angles

=> your shake fix isn’t doing anything. that cannot be right, so your shake parameters must be wrong.

logically, that means, that your time step is *far* too large, which is easily seen by looking at your temperature.

it jumps quickly to over 5000K and by the time you see your crash it has reached a value beyond 300,000K

well, the real question is: how does this *not* worry you? and how can you say, that you cannot see anything wrong with your simulation until it crashes.

axel.