ACD/Sigma Batch       Click image to magnify

General Overview

ACD/Sigma Batch allows you to directly access the Hammett electronic substituent constant, σ, calculated for selected fragments of your molecule or the substituents of your library for large sets of compounds presented in a number of electronic formats.

This permits you to make an in-depth analysis of the steric effects, the hydrophobic constant (the π constant of Hansch), and related phenomena of the various substituents in the molecule of interest.

To make a calculation, either one SDfile, containing a list of substituents, or two SDfiles, describing the core molecule (scaffold) and the library, can be used to generate sigma values.

This package is available for Microsoft Windows, SUN, and Linux platforms, and can be run from a Windows command line.

For more information on the used algorithm, as well as some interesting comparisons with our competitors - see the ACD/Sigma description.

Features

ACD/Sigma Batch

• Calculates sigma constants for numerous structures.
• Offers an option to calculate only Inductive and Resonance sigma constants.
• Is robust to interruption, and will try to save job to another file.
• Will output comments and warnings to a file.

How ACD/PhysChem Batch: Sigma Module works:

I. Input file

• ACD/ChemFolder database (.CFD)
• SMILES text file (.TXT)
• MDL SDfile (.SDF)*
• ISIS database (.DB)**

*Note: For more detail about this common text data exchange format, please refer to "MDL File Formats" at the MDL Inc. Web site.
**Note: ISIS/Base 2.2 must be installed on the same PC. 

II. Set options:

• Specify the location of an SDfile where the sample substituents for sigma calculation are placed.
• Specify whether the program should calculate only sigma inductive and sigma resonance.

III. Choose to report results to .SDF, .RDF, .CFD, or .TXT files.