# Re: CCL:Electrostatic solvation model

*From*: Andreas Bender <anbeajbj;at;cs.tu-berlin.de>
*Subject*: Re: CCL:Electrostatic solvation model
*Date*: Wed, 13 Mar 2002 21:33:04 +0100 (MET)

Hi Andrew,
I want to give you a simple illustration to your equation:
a) For a point charge, you have E = Q / (r * r) (in non SI-units).
b) Integrate that with respect to r, and you have U(r)= Q / r.
c) You have interactions each particle with each other particle. So
you have to sum up with respect to i and j.
d) But - now you counted each interaction twice! Divide by 2, and you have
the equation you mentioned.
I hope that was your point,
Good luck,
Andreas
On Wed, 13 Mar 2002, Andrew Horsfield wrote:
> Can anyone point me to a proof of the following equation for the
> electrostatic contribution to the solvation energy:
>
> U = 1/2 \sum_{ij} Q_i q_j / r_{ij}
Mit freundlichen Grüssen,
Andreas Bender
Andreas Kieron Patrick Bender
http://www.andreasbender.de