Re: [ESPResSo] Question about bond-angle interaction

[Lorenzo Isella]

Dear Hanjo,
Thanks for your reply. I am trying to follow the various pieces of
advice I get from the list, in increasing order of complexity. So, I
would start from the case of a binary collision.


> My suggestion would be the following:
> Case 1: two particles collide:
> FENE interaction:
> inter 0 fene 7 2 (<k> <max dist>)
> Identities: p1, p2
> part $p1 bond 0 $p2 (Syntax: part <part identity 1> bond <bond type
> number> <part identity 2>)

So, first I define the FENE interaction. which I call bond interaction
0, giving its strength and a characteristic interaction length and
then I have to apply it to individual particles, NOT to a particle
type, as Olaf pointed out.
In other words, should I embed your suggestion in a loop?
Something like (never mind the syntax at this stage) for a number of
particles N:

inter 0 fene 7 2
for i from 1 to N
for j from 1 to N
 if (i>j)
part $i bond 0 $j

i.e. I need explicitly a define the FENE interaction among all the
particle couples, avoiding to double-count them?
Of course there are many other aspects to clarify, but better not to
be too ambitious at this stage.
Many thanks

Lorenzo