Hello Henning, I took a look at your convergence problem. I think the problem is in the definition of two copper polysulfide species. It should be -mass_balance Cu(1)(S(-2)4)2 and Cu(1)S(-2)4S(-2)5. As it is currently defined, these species are going into the Cu(2) mole balance, but adjusting the Cu+2 activity makes no difference in their concentration because Cu+ is in the mass action equation. Changing the -mass_balance puts the species in the Cu(1) mass balance. I'm not fond of polysulfide species anyway; they are metastable, so there is a question of whether they should be used in a model, and they tend to cause convergence problems. Hope this helps. Good to hear from you and take care, David David Parkhurst (dlpark@xxxxxxxx) U.S. Geological Survey Box 25046, MS 413 Denver Federal Center Denver, CO 80225
Please note that some U.S. Geological Survey (USGS) information accessed through this page may be preliminary in nature and presented prior to final review and approval by the Director of the USGS. This information is provided with the understanding that it is not guaranteed to be correct or complete and conclusions drawn from such information are the sole responsibility of the user.
Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government.
The URL of this page is:
Last modified: $Date: 2005-09-13 21:04:21 -0600 (Tue, 13 Sep 2005) $
Visitor number 1382 since Jan 22, 1998.