The user also has the possibility to load datasets with experimental data to be used instead of the estimated descriptors. This is illustrated with an example below of loading a database with experimental log Kow results.
1. Prepare the external file with parameter (calculator) values
The external file should be a text format with experimental data with the following structure:
SMILES<Tab>Value<Tab>Units
Please note that in case the descriptor is dimensionless, each line should nevertheless
contain a after the Value. Example of a text file is presented in Box 1.
Example of external file with experimental parameter (calculator) values:
Copy these columns into the Notepad and save it as a file with “.txt” extension.
2. Go to the Options by clicking on the Options icon (in the shape of a wrench) in the
upper right-hand corner (1).
Click on Define new calculator (1).
Then a dialogue box Define new calculator pops up.
3. The steps of introducing the external file with parameter (calculator) values in the Toolbox are (see also screenshot below):
(1) Add a title. In this example “Experimental log Kow”
(2) Add a dimension or unit. In this example the descriptor is dimensionless and the field is left blank.
(3) Select a type: 2D or 3D. The distinction is made depending on whether the descriptor could be calculated based on a 2D or 3D configuration of the structure. Kow being usually derived from a 2D structure, the 2D button can be selected.
(4) Indicate the path of the file containing external experimental data.
(5) The user can choose an existing calculator to estimate the descriptor for chemicals not listed in the file with experimental data. In this example, “log Kow” (calculated by the EPISUITE model) could be chosen to fill data gaps in the experimental file.
(6) Please note that if an alternative calculator is chosen, the radio button From file and calculated has to be checked.
(7) By clicking the OK button, the file is imported as a new descriptor. And the user can
return to a normal work session.
