Tuning ab initio data to scattering length: the a (3)Sigma(+) state of KRb

Area of Science:

• Quantum Chemistry
• Molecular Physics
• Spectroscopy

Background:

• Potassium-rubidium (KRb) is a key molecule for ultracold atom research.
• Accurate potential energy curves are crucial for understanding KRb's properties.

Purpose of the Study:

• To calculate interaction energies for the lowest triplet state a (3)Sigma(+) of KRb.
• To develop a potential energy curve that matches experimental data for KRb.

Main Methods:

• High-level ab initio calculations were performed.
• Interaction energies were morphed to match experimental scattering length and vibrational spacings.

Main Results:

• The study yielded a potential energy curve with 32 bound states for KRb.
• Calculated vibrational spacings closely agreed with experimental Fourier transform and photoassociation data.

Conclusions:

• The ab initio calculations provide a reliable potential energy curve for the KRb a (3)Sigma(+) state.
• A revised vibrational assignment scheme is proposed for experimental data.