Each quantity can also be limited to certain bounds. For instance an impurity is known to be positive because of physical restrictions and therefore a minimum limit of zero can be set. This sometimes results in a higher convergence rate due to the fact, that erroneuos calculations during Newton iterations are cut off. Sometimes this strict limitation reduces the convergence or even prevents the system from converging. Therefore, this opportunity should be used with care.

MinLimit(<QuantityName>) = <minimum limit value> MaxLimit(<QuantityName>) = <maximum limit value>

Finally a separate epsilon value can be assigned to each quantity as a limitation for the Newton iterations. Thus for quantities of less importance or accuracy the Newton iteration can be stopped earlier:

Epsilon(<QuantityName>) = <value>

1998-12-11