Solver

The Solver section controls how the simulation does its arithmetic, over what time, and to what accuracy. These are the settings most likely to affect how long your run takes and how accurate it is.

For most models the defaults work well. Adjust them only if your simulation is too slow, unstable, or needs finer time resolution.

Setting	What it controls
Initial time	The start time of the simulation (usually 0).
Final time	The end time. The simulation runs until this point.
Fixed step time (dt)	The size of each time step. Smaller steps are more accurate but slower.
Verbose	Print extra information to the log.
Solver type	The numerical method used to solve the equations.
Safety factor	A factor that keeps the time step safe; usually leave at the default.
Numerical damping	How much energy is intentionally dissipated each second.
Adaptive time stepping	Let the solver choose the step size automatically (recommended).
Stable step difference	How many steps are needed before the calculation is trusted to be stable.
Maximum bond difference	Bonds allowed to break in a single step.
Stable bond difference	The steady number of bonds breaking per step.
Stop after damage initiation	Stop the run as soon as the first damage appears.
Stop before damage initiation	Stop the run just before damage would appear.

Tip: if your run blows up with huge, erratic numbers, that’s often a sign of instability — the time step may be too large. Try enabling adaptive time stepping, which adjusts the step automatically.