What is Phi in fix Wall/colloid equation?

Dear Steve,

I was wondering what “phi” is in the equation on the webpage documentation of fix wall/colloid. It does not seem to be an input parameter and there is no discussion of that in the text also. In addition, it is possible to get a reference of the prefactors. “Where does the factor of 144 comes from” in the equation.

Thanks for your help.

Best Regards,

I think the phi is a typo, the prefactor should just be
epsilon dependent. I also think the 144 comes from the
integration over the infinite wall. Let me check with the folks
who derived this ...


Thanks Steve,
Thanks for clarifying the confusion. I will wait for your answer regarding the prefactor of 144.

Best Regards,