On the relationship between spectroscopic constants of diatomic molecules: a machine learning approach

Through a machine learning approach, we show that the equilibrium distance, harmonic vibrational frequency and binding energy of diatomic molecules are related, independently of the nature of the bond of a molecule; they depend solely on the group and period of the constituent atoms. As a result, we show that by employing the group and period of the atoms that form a molecule, the spectroscopic constants are predicted with an accuracy of <5%, whereas for the A-excited electronic state it is needed to include other atomic properties leading to an accuracy of <11%.

Automated summary

The research shows that the spectroscopic constants of diatomic molecules are related to the group and period of the constituent atoms, regardless of the nature of the bond. By considering the group and period of the atoms, the spectroscopic constants can be predicted with an accuracy of less than 5%. Additional atomic properties are needed for predicting the constants for the A-excited electronic state, leading to an accuracy of less than 11%.