التفاصيل البيبلوغرافية
| العنوان: |
Potential energy surfaces from many-body functionals: Analytical benchmarks and conserving many-body approximations |
| المؤلفون: |
Giovanna Lani, Nicola Marzari |
| المصدر: |
Physical Review Research, Vol 6, Iss 4, p 043304 (2024) |
| بيانات النشر: |
American Physical Society, 2024. |
| سنة النشر: |
2024 |
| المجموعة: |
LCC:Physics |
| مصطلحات موضوعية: |
Physics, QC1-999 |
| الوصف: |
We investigate analytically the performance of many-body energy functionals, derived by Klein, Luttinger, and Ward, at different levels of diagrammatic approximations, ranging from second Born, to GW, to the so-called T matrix, for the calculation of total energies and potential energy surfaces. We benchmark our theoretical results on the extended two-site Hubbard model, which is analytically solvable and for which several exact properties can be calculated. Despite its simplicity, this model displays the physics of strongly correlated electrons: it is prototypical of the H_{2} dissociation, a notoriously difficult problem to solve accurately for the majority of mean-field-based approaches. We show that both functionals exhibit good to excellent variational properties, particularly in the case of the Luttinger-Ward one, which is in close agreement with fully self-consistent calculations, and we elucidate the relation between the accuracy of the results and the different input one-body Green's functions. Provided that these are wisely chosen, we show how the Luttinger-Ward functional can be used as a computationally inexpensive alternative to fully self-consistent many-body calculations, without sacrificing the precision of the results obtained. Furthermore, in virtue of this accuracy, we argue that this functional can also be used to rank different many-body approximations at different regimes of electronic correlation, once again bypassing the need for self-consistency. |
| نوع الوثيقة: |
article |
| وصف الملف: |
electronic resource |
| اللغة: |
English |
| تدمد: |
2643-1564 |
| Relation: |
https://doaj.org/toc/2643-1564 |
| DOI: |
10.1103/PhysRevResearch.6.043304 |
| URL الوصول: |
https://doaj.org/article/18aeb3a0812c4894ac20f5616b16074c |
| رقم الانضمام: |
edsdoj.18aeb3a0812c4894ac20f5616b16074c |
| قاعدة البيانات: |
Directory of Open Access Journals |