BCF Crystal Growth Theory

[dirk]

I am interested in writing a simple script that incorporates the BCF crystal growth theory equation but when I run React I get fluctuating precipitation/dissolution for the precipitating mineral. The result is fluctuating positive then negative mineral mass for siderite (with initial mass = 0). This occurs when the mineral mass is very low 1e-186 but this low number is the nature of the nonlinear BCF. When left to run, the mass keeps going from positive to negative.

Is there some way to write in the script something to prevent the negative numbers? It appears to be a complete transition from positive to negative to positive, ie. the next logical number in the series during the reaction can end up being the opposite sign.

 

Any help is much appreciated.

 

Attached is the script for siderite.

 

Dirk