# PDESolverCaller Plugin¶

Warning

In most cases you can specify extra calls to PDE solvers in the solver itself. Thus this plugin is being deprecated. We mention it here for backward compatibility reasons as some of the older CC3D simulations may still be using this plugin.

PDE solvers in CompuCell3D are implemented as steppables . This means that by default they are called every MCS. In many cases this is insufficient. For example if diffusion constant is large, then explicit finite difference method will become unstable and the numerical solution will have no sense. To fix this problem one could call PDE solver many times during single MCS. This is precisely the task taken care of by PDESolverCaller plugin. The syntax is straightforward:

<Plugin Name="PDESolverCaller">
<CallPDE PDESolverName="FlexibleDiffusionSolverFE"ExtraTimesPerMC="8"/>
</Plugin>


All you need to do is to give the name of the steppable that implements a given PDE solver and pass let CompCell3D know how many extra times per MCS this solver is to be called (here FlexibleDiffusionSolverFE was 8 extra times per MCS).