Atom Pair Contribution Method: Fast and General Procedure To Predict Molecular Formation Enthalpies

An atom pair contribution
(APC) model aimed at predicting the gas-phase
formation enthalpy (ΔfH°) of
molecules is reported. In contrast to bond contribution (BC) or group
contribution (GC) methods, it relies on increments associated with
pairs of bonded and geminal atoms along with 15 structural corrections.
Another distinctive feature of the present APC method is the large
amount of experimental and high-level theoretical data specially compiled
in this work to fit and validate the model (2671 entries). Unlike
GC methods, the present APC model has wide applicability with the
number of adjustable parameters limited to 68. Although it requires
only a structural formula as input and involves only back-of-the-envelope
calculations, it is more reliable than state-of-the-art quantitative
structure–property relationship methods, popular semiempirical
Hamiltonians, and even low-level density functional theory approaches
based on gradient-corrected functionals. It is therefore a valuable
tool for fast screening applications or whenever chemical accuracy
is not necessary.