Question about r_cut behavior in Expanded Yukawa potential with non-zero delta parameter -azplugins

[judevishnu]

Hi,

I’m posting here because I wasn’t sure where to ask questions about azplugins.

I want to use the Expanded Yukawa pair potential with a non-zero delta parameter. The documentation does not mention exactly how the cutoff r_cut is applied in this case.

Should I assume that the Expanded Yukawa potential goes to zero for:

1. Distances greater than r_cut, or

2) Distances greater than delta + r_cut?

When I checked the backend code, it looks like the delta parameter is not considered in the cutoff criterion.

I just want to confirm whether the intended behavior is that the interaction is always truncated strictly at r_cut, regardless of the value of delta.

Thanks in advance!
best,
Jude

[mphoward]

I want to use the Expanded Yukawa pair potential with a non-zero delta parameter. The documentation does not mention exactly how the cutoff r_cut is applied in this case.

It isn't documented explicitly because the behavior is the same as everywhere else in hoomd (including the built-in Expanded potentials): the potential is truncated at the specified r_cut.

[judevishnu]

Thank you for your reply.