Differences

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--- models:analytic [2018/09/23 18:22] – removed daniel
+++ models:analytic [2019/02/23 09:48] – daniel
@@ Line 1: / Line 1: @@
+~~NOTOC~~
+====== Analytic potentials ======
+----
+Analytic potentials use the parameters $\alpha_i$ as arguments to analytic function templates.
+A well-known example for this would be the Lennard-Jones potential, which uses two parameters $\epsilon$ and $\sigma$ to define a potential:
+$$V(r)=4\varepsilon\left[\left(\frac{\sigma}{r}\right)^{12}-\left(\frac{\sigma}{r}\right)^{6}\right]$$
+{{ :analytic.png?300 }}
+Using an analytic form for $V(r)$ allows to define the atomic interaction for all possible distances between atoms with very few parameters compared to tabulated potentials. The problem of local parameters (see [[#Tabulated potentials]]) is also not present, parameters are usually global parameters. In certain cases it is even possible to attribute some physical meaning to individual parameters.
+The analytic potential implementation in //potfit// has additional features which are only useful with this kind of interactions. They are described on the [[potfiles::format0|analytic format]] page.