The numbers of solvent molecules in the soln and refs systems need be identical to each other. They are of course integers, but in the slvfe program, the numbers of solvent molecules are calculated as real values from the engsln and engref inputs. The tiny parameter is the allowance for the coincidence of the two real values representing the numbers of solvent molecules. The default setting is tiny = 1.0e-10. When the difference between the numbers of solvent molecules obtained from engsln and engref exceeds tiny, the slvfe program terminates with an error message of Incorrect normalization at (number specifying the solvent species). A workaround is provided in Error in slvfe: Incorrect normalization at (integer value).
However, the default setting of tiny = 1.0e-10 could be too stringent since it is a measure of cancellation of significant digits. Further, the value of 1.0e-10 does not have much meaning in itself. A value with more sound justification could be sought.
