A note on perturbation-adapted perturbation theory

The partitioning introduced recently by Knowles [J. Chem. Phys. 156, 011101 (2022)] is analyzed and its connections with the Adams partitioning and the Davidson-Kapuy partitioning are discussed. Davidson's partitioning is reformulated using the second quantized formalism. A relation is pointed out between the Knowles condition for the many-body perturbation theory zero order Hamiltonian and the CEPA0 equations.& nbsp;Published under an exclusive license by AIP Publishing.

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This paper analyzes the partitioning introduced recently by Knowles, discussing its connections with the Adams partitioning and the Davidson-Kapuy partitioning. Davidson's partitioning is reformulated using the second quantized formalism. A relation is pointed out between the Knowles condition for the many-body perturbation theory zero order Hamiltonian and the CEPA0 equations.