(no subject)

Hi All,

I set the pair-style Buck for non-bonded interactions in my system . There is no mixing rule for Buckingham so I need to provide the coefficients for all atom pairs. I have three atom types (two of them are bonded together and have non-bonded interactions with type 3) and defined the pairwise interactions as

1 1 (type 1 type 1)

2 2

3 3

1 2

1 3

2 3

I also have a bond (bond_style Morse) between type 2 3.

Do I need to exclude the pair interaction 2 3 by neigh_modify exclude type 2 3 ?

I’m not sure if I can use Special_bonds for Buckingham to exclude the bond or not?

Thank you in advance.

Best,

Leila

Hi All,

I set the pair-style Buck for non-bonded interactions in my system . There
is no mixing rule for Buckingham so I need to provide the coefficients for
all atom pairs. I have three atom types (two of them are bonded together and
have non-bonded interactions with type 3) and defined the pairwise
interactions as

1 1 (type 1 type 1)

2 2

3 3

1 2

1 3

2 3

I also have a bond (bond_style Morse) between type 2 3.

Do I need to exclude the pair interaction 2 3 by neigh_modify exclude type 2
3 ?

no. this would be wrong, since you don't have bonds between *every*
combination of type 2 and 3 even if they are further apart. you only
want to exclude the pairs that have an explicit bond defined between
them.

I'm not sure if I can use Special_bonds for Buckingham to exclude the bond
or not?

exclusion of bonded interactions defined in your data file works
independent of the pair style. because those pairs are removed from
the neighbor list.
the only question would be, if you have a special bonds value
different from 1.0 or 0.0. but also that one is honored in the
buckingham pair style.

axel.

Dear Axel,
Thank you.

Best,
Leila