SPECIFICATIONS FOR A NEW JACOBIAN PACKAGE FOR THE RAND CHEMICAL EQUILIBRIUM PROGRAM

Abstract : This study describes and gives instructions for using a new and improved Jacobian package consisting of a group of subroutines for RAND's chemical equilibrium program. This new package, which has a much greater scope than the earlier version, computes Jacobian matrices consisting of partial derivatives of certain quantities in the solution of a model (dependent variables) with respect to certain parameters in the model (independent variables). With the use of these derivatives, it is possible to predict how a change in a model parameter can affect the model solution. In many cases the user can obtain a good approximation for how much effect a certain type of change will have without resolving the problem. The derivatives might be used, for example, to see how much the pH of a model might change with an increase in the pressure of carbon dioxide, or with an increase in the amount of sodium hydroxide. (Author)