Sub-system self-consistency in coupled cluster theory

• URL: http://arxiv.org/abs/2209.04713v2
• Date: Thu, 24 Nov 2022 22:19:19 GMT
• Title: Sub-system self-consistency in coupled cluster theory
• Authors: Karol Kowalski
• Abstract summary: We show that the standard single-reference coupled-cluster (CC) energies can be calculated alternatively to its copybook definition. In the extreme case, we provide numerical evidence that the CC energy can be reproduced through the diagonalization of the effective Hamiltonian describing sub-system composed of a single electron.
• Score: 0.0
• License: http://creativecommons.org/licenses/by/4.0/
• Abstract: In this Communication, we provide numerical evidence indicating that the standard single-reference coupled-cluster (CC) energies can be calculated alternatively to its copybook definition. We demonstrate that the CC energies can be reconstructed by diagonalizing the effective Hamiltonians describing correlated sub-systems of the many-body system. In the extreme case, we provide numerical evidence that the CC energy can be reproduced through the diagonalization of the effective Hamiltonian describing sub-system composed of a single electron. These properties of CC formalism can be exploited to design protocols to define effective interactions in sub-systems used as a probe to calculate the energy of the entire system and introduce a new type of self-consistency for approximate CC approaches.

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