Alternative analytical forms to model diatomic systems based on the deformed exponential function

Area of Science:

• Theoretical Chemistry
• Computational Chemistry
• Spectroscopy

Background:

• Accurate representation of potential energy curves is crucial for understanding molecular behavior.
• Existing analytical functions may have limitations in describing diverse diatomic systems.
• Molecular-orbital theory provides a framework for electronic structure calculations.

Purpose of the Study:

• To propose two novel analytical functions for diatomic potential energy curves.
• To evaluate the accuracy of these functions for ground-state diatomic systems.
• To assess their performance across homonuclear, heteronuclear, and cationic species.

Main Methods:

• Development of two new analytical functions based on deformed exponential functions.
• Application of molecular-orbital theory for ab initio electronic energy calculations.
• Fitting ab initio energies of various diatomic systems (LiH, H2, H2+, etc.) to the proposed functions.

Main Results:

• The proposed analytical functions effectively represent potential energy curves for ground-state diatomic molecules.
• Excellent agreement was observed when fitting ab initio electronic energies for LiH, H2, and other systems.
• The functions demonstrated good accuracy for homonuclear, heteronuclear, and cationic diatomic systems.

Conclusions:

• The new analytical functions provide a robust and accurate method for modeling diatomic potential energy surfaces.
• Vibrational spectroscopic constants derived from these functions align well with experimental values.
• These functions offer a valuable tool for theoretical studies of diatomic systems.