huge difference in energy with different pair_style

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1

Dear All
I would like to check correct force field (Dreiding and reax) to my system(hexanthiol).
I found the huge difference in total energy among these two pair_style.
In reax its coming around -1900 kcal/mol.
Whereas in Dreiding its coming around -2.00 eV.
I am attaching my data files, input scripts as well as log files.
What could be the reason for this huge difference? or Am i doing anything wrong?

Thanks
Mathi

data.hexan_dreiding_ms_charge (55.9 KB)

data.hexan_dreiding_ms_charge_reax (12.5 KB)

in.hexan_eam (1.86 KB)

in.SC6H13_reax (1.5 KB)

log.lammps_lj (7.34 KB)

log.lammps_reax (6.85 KB)

2

Dear All
I would like to check correct force field (Dreiding and reax) to my
system(hexanthiol).
I found the huge difference in total energy among these two pair_style.
In reax its coming around -1900 kcal/mol.
Whereas in Dreiding its coming around -2.00 eV.
I am attaching my data files, input scripts as well as log files.
What could be the reason for this huge difference? or Am i doing anything
wrong?

total energy has no meaning for anything using empirical potentials.
only energy differences matter (and gradients).

axel.

3

Thank you Axel