SED & PREDOM / EC

EC: Equilibrium Calculations

Format of the Input Data-File

Input data files for EC consist of: 1) definition of the chemical system; 2) number of calculation points; and 3) concentrations (ranges) for the chemical components.

The number of calculation points for EC is as follows:

NPKT

The value of NPKT may be positive or negative.

If NPKT is less than zero, −NPKT points will be calculated, and the input for each point to be calculated must be given, as indicated in concentrations, by using "T" or"LA" for each chemical component. It is convenient to have −NPKT lines in the input file, one for each calculation point, and in each line provide the concentration for each component.

For example, for the system H⁺, Fe³⁺, Cl⁻ and SO₄²⁻, you could write:

	-2
	LA,-7, T,0.3, T,0.9, T,0
	LA,-8, T,0.3, T,0.9, T,0

to calculate two points with pH values of 7 and 8 with [FeCl₃]_Tot = 0.3 molal.

If NPKT is larger than zero, the input is made using concentration ranges for at least one of the components, as explained in concentrations. For example, with the chemical system above, you could write:

	7
	LAV,-5,-8, T,0.3, T,0.9, T,0

with NPKT = 7, seven calculations are made with pH values of 5.0, 5.5, ... 7.5, 8.0

See also: Input Data-Files for SED and PREDOM