A chemical selection evaluates a set of physical property and molecular structure constraints for a list of chemical candidates. These chemical candidates, their associated physical properties, and the estimation techniques used in the evaluation process are all obtained from the source knowledge base specified in the selection.

Synapse enables you to store the results of a selection back into the source knowledge base. In particular, each candidate's overall distance or selection ranking can be stored as an undesignated property. (See documentation on the Undesignated Data Section for additional information.)

1	Property Name Control: enables you to enter the name of the undesignated property. This property name will be used to create a datum to be stored with each chemical candidate.
2	Rank Value Controls: enables you to specify whether the value to be stored is the candiate's overall distance or its index in the list of candidates. (Typically you sort candidates by one or more criteria before you save an indexed ranking.)
3	Invalid Limit Control: enables you to select the number of constraints that a candidate may violate. These limits are enabled only if you are saving an indexed ranking.
4	Reference Control: the Reference control enables you to enter the identifier of a reference. You can type in a value or use the dropdown list to select a recently entered value. Entering a reference is optional but highly recommended.
5	List Button: pressing the List button displays the Reference Selection dialog. This dialog enables you to select the identifier of any reference in the current document. (See the All Entities dialog documentation for more details on selecting references.)
6	Comments Control: the Comments control enables you to enter general information to better describe the selected chemical candidate. Entering the date, time, and selection name is often useful.
7	Date, Phrase, Set Buttons: these buttons provide standard operations to help you enter comments. Pressing the Date button inserts the current date and time into the comment control. Pressing the Phrase button inserts the stored 'common phrase' into the comment control. Pressing the Set button enables you to change the 'common phrase'. (See documentation on the Set Phrase dialog for details.

1. Open the MKS Chemical Selection Examples document. (Open a "working" document or create a copy of a document (see here) if you are just experimenting with this functionality.)
2. Change to the Selections Chapter and navigate to the 'Example CS-001: Functional MeCl2 Alternative [MKS]' selection. (See the Navigation Overview documentation for details on navigating chapters and pages.)
3. Run the 'Select Chemicals' command from the chapter's Commands menu. The application actives the Chemical Selection Dialog. Press the dialog's Start button.
4. The dialog will apply the selection's constraints to each chemical in the source knowledge base. When the selection is complete, press the dialog's Save button.
5. The dialog will store all selection candidate's into the current document. Scroll down to the Candidates Section and click the left mouse button on the section's table control. The application activates the Chemical Selection Candiates Dialog.
6. Press the dialog's Select All button. Then press the dialog's Sort button. The application activates the Sort Attributes Dialog. Set the Order to be Ascending and the Attribute to be Distance. The press the dialog's OK button.
7. The selected chemical candidates will be sorted by overall distance. Press the dialog's Save button. The sorted candidates will be stored into the current document.
8. Select the Save Chemicals Ranking from the chapter's Commands menu. The application activates the Save Ranking Dialog.
9. The dialog enables you to enter values for the undesignated property, rank value, invalid limit, reference, and comments. Once you enter these values you would typically press the dialog's OK button. However, for this example, just press the dialog's Cancel button. (Pressing the OK button would store the results into the source knowledge base. This is not something we wish to do in this example.)
10. If you had press the OK button, the application would have created and added an undesignated datum to each saved candidate. For example, the following entry would have been added to Dichloromethane, the first candidate in our sorted list.

Topic	Description
Getting Started using Synapse	provides a quick tour of Synapse's capabilities including examples of chemical product design.
Getting Started using Cranium	provides a quick tour of Cranium's capabilities including a discussion of structure editing.
Estimating Chemical Properties	a short video demonstrating how to estimate the physical properties of chemicals using either Synapse or Cranium.
Estimating Mixture Properties	a short video demonstrating how to estimate the physical properties of mixtures using either Synapse or Cranium.