Problems with Defining Common Structure for R-group Analysis
The R-group Analysis Table Tool may not be able to define a common structure if
your R-group analysis includes:
Substance types that cannot be processed
Disparate or dissimilar structures
Multi-components in which the selected component is not a match
Answers that may cause the tool to fail include some polycyclic compounds, large
substances, and substances that do not include a structure in CAS REGISTRY
To minimize problems with defining common structure:
It may be helpful to check the box Use structure skeleton, ignore bonds to
define a common structure when the answer set contains structures with
bond variations. This checkbox may be used with either radio button: Use the
largest common structure or Use a saved structure query file.
Exclude alloys, coordination compounds, incompletely defined substances,
manually registered substances, polymers, and tabular inorganic substances.
The Save for R-group Analysis Wizard provides the option to exclude these
types of substances. If you have not excluded them, you can go back online,
redo your search, and Save for R-group Analysis. Alternatively, you can
make use of the structure preview on the File tab of the R-group Analysis
Table Tool to deselect the undesirable answers. Additionally, if you have
chosen to display these answers online in the IDE format, you can review
your transcript to identify these substances.
You may try to define your own structure by choosing Use a saved structure
query file on the Structure tab within the R-group Analysis Table Tool. To
create a saved structure, use the structure drawing tool available via
Query/Prepare Structure Query. Isolated rings are handled better by the R-
group tool than non-isolated rings.
Note: The R-group tool may alter the structure you provide in order to define
If your answer set includes multi-component substances, the first component
is selected by default. Within the File tab ensure that Preview R-group file is
selected. Scroll through the list of structures and choose the radio button for
the appropriate component in each answer.
If your answer set contains two or more subsets of different substructure
types (for example if the search was created via a text search), you will need
to process your answer set prior to creating an R-group table. To accomplish
this, ensure Preview R-group file is selected, check only those answers that
have the same substructure and use the Save Selected button to create a
new .rgp file. (If you have changed your component selection in multi-
component answers, that selection will not be maintained in the .rgp file you
create). Repeat this process as necessary to create additional .rgp files from
this answer set.
Note: If you are only creating two .rgp files, it may be useful to use the ”Invert
Selection” button to generate these two files. Run the R-group Analysis
Table Tool on the newly created .rgp file to create a table from that subset of