I have a cylinder for ions in order not to penetrate into the cylinder.
I am using fix indent command.
Force and Energy formula given in the Mannual are
F(r) = - k (r-R)^2
E = k/3*(r-R)^3
I am curious about the sign of k.
Is k positive if the cylinder repels ions ?
F(r) is attractive inside the cylinder.
I would like to know if this is a typo or not.
Any suggestion is greatly appreciated.