Differences

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--- models:openkim [2019/02/23 09:55] – created daniel
+++ models:openkim [2019/02/23 10:14] – daniel
@@ Line 3: / Line 3: @@
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-Analytic potentials use the parameters $\alpha_i$ as arguments to analytic function templates.
+//potfit// supports the [[https://openkim.org/|OpenKIM]] framework for defining atomic interactions. It is possible to use any OpenKIM model which publishes its parameters. Unfortunately it is currently not possible to check if a model does this on the web interface. //potfit// provides a small utility called ''kim_read_model_props'' which probes a model for supported features.
-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|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.