Can I relax a system with the dreiding force field?

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1

Hi all,

I compiled lammps with the simple command “make serial”.

I use the example at lammps/examples/dreiding/.

dump 1 all custom 1 dump_1 id x y z fx fy fz

dump_modify 1 sort id

min_style cg

minimize 1.0e-9 0.01 100 10000

If I add above commands to “in.dreiding”, and run lmp_serial, it stopped with a Stopping criterion = “linesearch alpha is zero”, and forces are much higher than the force tolerance.

Same result from 30Nov2016 and latest version 31Mar2017.

How can I relax the system to the force/energy tolerance?

Liping,

Thanks

2

Hi all,

I compiled lammps with the simple command “make serial”.

I use the example at lammps/examples/dreiding/.

*dump 1 all custom 1 dump_1 id x y z fx fy fz*

*dump_modify 1 sort id*

*min_style cg*

*minimize 1.0e-9 0.01 100 10000*

If I add above commands to “in.dreiding”, and run lmp_serial, it stopped
with a Stopping criterion = “linesearch alpha is zero”, and forces are much
higher than the force tolerance.

Same result from 30Nov2016 and latest version 31Mar2017.

How can I relax the system to the force/energy tolerance?

​minimizations can get "stuck" for many reasons, e.g. when the minimizer
cannot find out in which direction ​to go, which is what your stopping
criterion message means. forces do not have to be zero especially for
molecular systems. check out the cubane or cyclopropane molecules as
extreme examples.

axel.