Variational second-order Møller-Plesset theory based on the Luttinger-Ward functional

Area of Science:

• Computational chemistry
• Quantum chemistry
• Many-body physics

Background:

• Traditional variational methods for electronic systems rely on wave functions.
• A new variational technique has emerged, utilizing many-body perturbation theory.
• This technique employs the one-electron Green function as its core variable.

Purpose of the Study:

• To introduce and promote a novel variational technique in theoretical chemistry.
• To demonstrate the utility of the Green function method for calculating atomic correlation energies.
• To achieve accuracy comparable to second-order Møller-Plesset perturbation theory.

Main Methods:

• Application of a many-body perturbation theory-based variational technique.
• Utilizing the one-electron Green function as the primary variable.
• Calculating correlation energies for atomic systems.

Main Results:

• Successful application of the Green function-based variational method.
• Achieved correlation energy calculations at a level consistent with second-order Møller-Plesset perturbation theory.
• Demonstrated the method's potential for broader application in theoretical chemistry.

Conclusions:

• The Green function-based variational technique is effective for calculating atomic correlation energies.
• This method offers a viable alternative to traditional wave function-based approaches.
• The technique is generalizable to higher orders of perturbation theory.