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This keyword data block is used to define the correspondence between the name of an exchange site and an exchange species that is used as the master species in calculations. Normally, this data block is included in the database file and only additions and modifications are included in the input file.

Example data block

Line 1a:     X     X-
Line 1b:     Xa    Xa-



Keyword for the data block. No other data are input on the keyword line.

Line 1: exchange name, exchange master species

exchange name --Name of an exchange site, X and Xa in this example data block. It must begin with a capital letter, followed by zero or more lower case letters or underscores ("_").

exchange master species --Formula for the master exchange species, X - and Xa - in this example data block.


All half-reactions for the exchanger (X and Xa, in this example data block) must be written in terms of the master exchange species (X - and Xa - in this example data block). Each exchange master species must be defined by an identity reaction with log K of 0.0 in EXCHANGE_SPECIES input. Any additional exchange species and associated reactions must be defined with EXCHANGE_SPECIES input.

Example problems

The keyword EXCHANGE_MASTER_SPECIES is not used in the example problems. See listing of default database file in Attachment B for an example.

Related keywords

EXCHANGE, EXCHANGE_SPECIES, SAVE exchange, and USE exchange.

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