EQPT, a data file preprocessor for the EQ3/6 software package: User's guide and related documentation (Version 7.0)

EQPT is a data file preprocessor for the EQ3/6 software package. EQ3/6 currently contains five primary data files, called datao files. These files comprise alternative data sets. These data files contain both standard state and activity coefficient-related data. Three (com, sup, and nea) support the use of the Davies or B equations for the activity coefficients; the other two (hmw and pit) support the use of Pitzer's (1973, 1975) equations. The temperature range of the thermodynamic data on these data files varies from 25 degrees C only to 0-300 degrees C. The principal modeling codes in EQ3/6, EQ3NR and EQ6, do not read a data0 file, however. Instead, these codes read an unformatted equivalent called a data1 file. EQPT writes a datal file, using the corresponding data0 file as input. In processing a data0 file, EQPT checks the data for common errors, such as unbalanced reactions. It also conducts two kinds of data transformation. Interpolating polynomials are fit to data which are input on temperature adds. The coefficients of these polynomials are then written on the datal file in place of the original temperature grids. A second transformation pertains only to data files tied to Pitzer's equations. The commonly reported observable Pitzer coefficient parameters are mapped into a set of primitive parameters by means of a set of conventional relations. These primitive form parameters are then written onto the datal file in place of their observable counterparts. Usage of the primitive form parameters makes it easier to evaluate Pitzer's equations in EQ3NR and EQ6. EQPT and the other codes in the EQ3/6 package are written in FORTRAN 77 and have been developed to run under the UNIX operating system on computers ranging from workstations to supercomputers