Evaluating Chemical Terms functions can be done via the Chemical Terms KNIME node. This type of node accepts a molecule as an input, and performs the specified calculation on it. The calculation is defined as a Chemical Terms function in the Options window. (Available function names appear as you type the starting letters of it. A brief description of the function also appears.) The result of the calculation is usually passed to an output node.
In the example below you can see the specified input and KNIME nodes that performs the calculation: