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Compare heats of formation at 298K for semiempirical levels and group additivity methods

Group additivity method as implemented in the NIST Chemistry webbook (

Enter Formula

or choose by chemical groups.

Rules for chemical formula

Species in the CCCBDB

Going to the group selection page allows the selection of molecules with certain chemical groups, such as C=O bonds or NH2 groups. A list of species that match the group criteria is returned and one or more may be selected.