THIS INFORMATION IS OBSOLETE AND IS PROVIDED ONLY FOR ITS HISTORICAL VALUE

A general procedure has been developed for the systematic generation of molecules that incorporate specified structural groups, for identifying all heavy-atom torsions of the conformer (usually) of minimum energy, and for assigning a gauche enthalpy to each torsion. The estimates of gauche enthalpies are derived by an interpolation procedure which provides a consistent set of values. The intended use of the procedure is to provide a general way of deriving standards for the definition of Formal Steric Enthalpies for new classes of compounds. The sum of the gauche enthalpies for all torsions for the conformer of minimum energy may be assigned as the formal steric enthalpy for the standard.

The programs, FSEUNITA.BAS, FSEUNITB.BAS and FSEUNITC.BAS, together with a data set (TORSION.DAT) implement the procedures. FSEUNITA.BAS includes descriptors of substituent groups, such as H, C, COOH, NH2, and writes a file UNITS.DAT.FSEUNITB.BAS accepts torsion descriptors and calculates interpolated gauche enthalpy values based on a modified Buckinhgam potential; it produces the file TORSION.DAT. UNITS.DAT and TORSION.DAT are used by FSEUNITC.BAS to generate the molecules as described.

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