Bond Dissociation Energy Skill

Goal

Calculate the homolytic and/or heterolytic bond dissociation energy (BDE) for each single bond in a molecule using Machine Learning Interatomic Potentials (MLIPs).

Homolytic BDE (radical fragments): $$\text{BDE}_\text{homo}(A{-}B) = E(A\bullet) + E(B\bullet) - E(A{-}B)$$

Heterolytic BDE (ionic fragments, minimum over both polarity variants): $$\text{BDE}_\text{hetero}(A{-}B) = \min!\bigl(E(A^+)+E(B^-),; E(A^-)+E(B^+)\bigr) - E(A{-}B)$$

[!IMPORTANT] This skill computes BDEs by relaxing both the intact molecule and fragments with an MLIP. For purpose-trained GNN models that predict BDE directly from SMILES (MAE ~0.6 kcal/mol), consider ALFABET or BonDNet instead.

Background