[lammps-users] Coefficient of pair_style morse

Dear all,
In lammps,if I want to use the pair potential Morse,I should assign five coefficients:global cutoff for Morse interactions,D0,alpah,r0,cutoff.
So I have some questions.
What’s the difference between the first cutoff and the last cutoff?Are they usually the same?
In general,how can I assign the cutoff?
Thanks.

2010/11/23 David <[email protected]>:

Dear all,
In lammps,if I want to use the pair potential Morse,I should assign five
coefficients:global cutoff for Morse interactions,D0,alpah,r0,cutoff.
So I have some questions.
What's the difference between the first cutoff and the last cutoff?

if you dont provide a cutoff with the pair coefficients, then the global
cutoff parameter is used. i.e. the one provided with the pair style is
the default, the one given with the pair coefficient an override.

Are they usually the same?

yes, that is why the pair coefficient parameter is optional.

In general,how can I assign the cutoff?

you _have_ to give a cutoff with the pair style command,
the other is optional.

the manual is very clear about this, in my opinion.
so can you please explain to us, where you are
getting confused and how this could be written better.

thanks,
     axel.

axel.