The Chemicals Chapter's General Calculations Section enables you to estimate or calculate properties that are not present in Cranium or Synapse. For example, you can calculate the heat transfer coefficient of a chemical at the conditions in a particular piece of process equipment. General calculations are also useful for specifying chemical families, e.g., acyclic monoolefins or cyclic alkanes.

A General Calculation is entered just like any other estimation technique. See the Technique Chapter's documentation for more details.

A general calculation is added to the General Calculations Section by clicking the left mouse button on the section's main field. The application will display the General Calculations dialog. This dialog will enable you to add or remove general calculations from the section.

Once you have added one or more general calculations, you can click the right mouse button on the section's main field. The application will activate the commands menu. Selecting the Calculate Values command will calculate values for each entered calculation.

General Calculations are also calculated when you select the Compute Estimates command from the Chemical Chapter's Commands menu.

Clicking the left mouse button on the section's large table control activates the General Calculations Dialog.

1	Values Table: the dialog's large table enables the name of the general calculation (the name of the estimation technique) in the first column and the calculated value in the second column. Clicking the left mouse button on a table row will enable the Edit button. Double clicking the left mouse button on a row will edit that row. Selecting more than one row by clicking and dragging the left mouse button enables the Sort button.
2	Edit: clicking the left mouse button on a table's row will enable the Edit button. Pressing the edit button activates the General Calculation dialog which enables you to enter or edit the calculation's estimation technique. (See below for details.)
3	Commands: pressing the Commands button, or clicking the right mouse button on the section's table control, activates the command menu. These commands enable you to copy, paste, clear, insert, delete, and select table rows. See the Common Menu Commands documentation for details on each command.
4	Sort: when more than one row is selected in the section's table control, the Sort button will be enabled. Pressing the Sort button will enable you to sort, in ascending or descending order, by technique or value.
5	Add Rows: add more rows to the bottom of the section's table control. Note that additional rows are typically automatically added when needed because of editing, pasting, or inserting rows.
6	Save: pressing the Save button will close the dialog and store the entered data into the current design document.

Double clicking the left mouse button on a row in the General Calculations dialog or selecting a row and pressing the dialog's Edit button activates the General Calculation dialog.

1	Technique Name: this text control is used to enter and display the name of the estimation technique used to perform the general calculation. You may type in the name of the technique or use the dialog's Find button to select the technique's name from a list.
2	Find Button: pressing the dialog's Find button activates the General Calculation selection dialog. The dialog lists all the general chemical calculation techniques in the current knowledge base. The technique's reference and general notes are also displayed. To select a technique: 1) click the left mouse button on the name of a technique; 2) press the dialog's OK button.
3	Calculated Value: if a value has been calculated it is displayed in the dialog's Calculated Value text control. You cannot change this value but you may copy it by selecting the text, clicking the right mouse button within the control, and selecting the Copy Text command from the displayed commands menu. To clear the calculated value, use the commands found in the General Calculations dialog discussed previously.
4	Comment Control: displays the comment generated by the application when the selected technique was used to calculate the displayed value.
5	Tech Ref Button: each estimation technique can have an associated reference. (See the Technique Information Section documentation for details.) Pressing the Tech Ref button will display the document associated with this reference.
6	OK Button: if you make any changes to the technique's name, the OK button will be enabled. Pressing the OK button will save your changed to General Calculations dialog.

1. Open the MKS Core Knowledge Base document. Create a working copy of the document (see here) to use with this example.
2. Change to the document's Chemicals chapter and navigate to a chemical of interest.
3. Scroll down to the General Calculations section (near the bottom of the page) and click the left mouse button in the field’s table. The application activates the General Calculations dialog.
4. Select an empty row and press the dialog’s Edit button. The application activates the General Calculation dialog.
5. Press the Find button and select the 'GenCalc: Specific Gravity at 20°C [MKS]' technique.
6. Press the dialog's OK button to save your changes to the General Calculations dialog. Then press that dialog's Save button to save your changes into the current knowledge base.
7. Click the right mouse button on the General Calculations Section's table control. Select the Calculate Values command from the displayed commands menu.
8. The application will use the entered techniques to calculate values for the current chemical.

Topic	Description
Estimating Chemical Properties	a short video demonstrating how to estimate physical properties using either Synapse or Cranium.
Getting Started using Cranium	provides a quick tour of Cranium's capabilities including physical property estimation and a discussion of structure editing.
Chemicals Chapter	the chemicals chapter contains numerous sections for entering and displaying data and estimates including the chemical structure section.