Some “redox” cases (for example an excess free electrons without any
material left to be reduced) cannot be handled. Limit in that case the concentration
range to reasonable values.
The programs also fail if the activity for a solid component is given, but some other
conditions are also given which make the solid component not stable. For example:
In very acid media an oxide or carbonate can not have
activity = 1.
A copper(II) compound is not stable under very reducing conditions
(where Cu metal is stable), do not give its activity = 1.
Iron metal is not stable under an oxygen atmosphere: do not set
both the O2(g) and Fe(cr) activities to
fixed values.
Input errors should not occur if the input file has been created
with DATABASE. Common errors
if you modify the input file your-self:
Check that all components that are specified as solid
(SOLIDC in the first input line, see data-file format)
indeed do correspond to solid phases. The programs assume that the last SOLIDC
components are the solid ones.
Look for erroneous equilibrium constants and/or stoichiometric coefficients.
Check stoichiometric coefficients: calculate a diagram with SED by setting the
ionic strength to a non-zero value
(for example: 0.1 M). The program will check for electroneutrality
in all equilibrium reactions and give warning messages for non-balanced reactions.
This only works if correct electrical charges are given in the
names of all chemical species.
