A new simple analytical diatomic potential energy function that can be considered an extension of the prototypical Lennard-Jones model is proposed and tested. Five- and six-parameter models are considered and these can be easily constructed from widely available low-order vibrational-rotational constants and the dissociation energy. Accuracy tests are carried out on the ground electronic states of sixteen diatomic molecules. The proposed six-parameter function is found to be more accurate than other available few-parameter analytical models for the diatomic potential energy, and has accuracy comparable to that of modern high-level ab initio functions.
- Analytical diatomic potential
- Empirical diatomic potential function
- Extended Lennard-Jones potential