Actinide chemistry using singlet-paired coupled cluster and its combinations with density functionals.

Area of Science:

• Quantum Chemistry
• Computational Chemistry
• Spectroscopy

Background:

• Coupled cluster doubles (CCD) is a high-accuracy quantum chemical method.
• Static correlation is crucial for describing actinide molecules.
• Singlet-paired coupled cluster doubles (CCD0) offers a balance between accuracy and computational cost.

Purpose of the Study:

• To assess the accuracy of CCD0 and CCD0+DFT methods for ground-state properties of actinide molecules.
• To compare CCD0-based methods with established quantum chemical techniques.
• To investigate the performance of these methods for challenging f(0) actinyl and other actinide systems.

Main Methods:

• Utilizing singlet-paired coupled cluster doubles (CCD0) quantum chemical method.
• Employing combinations of CCD0 with density functional theory (DFT) functionals.
• Investigating variants using Brueckner orbitals.
• Calculating ground-state properties for selected actinide molecules.

Main Results:

• CCD0 and CCD0+DFT methods demonstrate good accuracy for ground-state properties of actinide molecules.
• These methods effectively capture the electronic structure of challenging systems like actinyls.
• Performance is comparable to established, more computationally expensive methods.

Conclusions:

• CCD0 and its DFT-augmented variants are reliable tools for studying actinide chemistry.
• These methods provide a computationally feasible approach to describing static and dynamic correlation in these systems.
• The findings support the use of CCD0-based methods for future investigations of actinide properties.