[lammps-users] system is not charge neutral

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1

Hi

I am simulating a charged polymer system and because of round offs, even though earlier I have charge equilibrated the system to produce total charge of 0.0000, the charges are printed in a reduced decimal way to allot a net charge for the system. If I take case of decimals somehow, net charge is reduced still it’s there in the order of 10^(-4) or ^-5, and I know that is not valid for kspace styles.

Is there other way, other than manually assigning it to get a net charge of 0.000000?..can we make lammps read only upto first few decimals somehow, so that it reads 0, rather than 0.000005?..or any other way?..i read on the forum that we may have to paint uniform charge density and I am not sure how to do it?

Thanks in advance
Chetan

2

I doubt that if the net charge is 1.0e-5 it will cause
the kspace solver any problems. If you don't want LAMMPS
to read the full precision of charge, then don't put it in
the data file. I.e. pre-process your file to remove the digits
you don't want in there.

Steve