Incorporating static intersite correlation effects in vanadium dioxide through DFT$+V$
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arXiv
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| Auteurs principaux: | , , , |
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| Format: | Preprint |
| Publié: |
2024
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| _version_ | 1866917983052365824 |
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| author | Haas, Lea Mlkvik, Peter Spaldin, Nicola A. Ederer, Claude |
| author_facet | Haas, Lea Mlkvik, Peter Spaldin, Nicola A. Ederer, Claude |
| contents | We analyze the effects on the structural and electronic properties of vanadium dioxide (VO$_2$) of adding an empirical inter-atomic potential within the density-functional theory$+V$ (DFT$+V$) framework. We use the DFT$+V$ machinery founded on the extended Hubbard model to apply an empirical self-energy correction between nearest-neighbor vanadium atoms in both rutile and monoclinic phases, and for a set of structures interpolating between these two cases. We observe that imposing an explicit intersite interaction $V$ along the vanadium-vanadium chains enhances the characteristic bonding-antibonding splitting of the relevant bands in the monoclinic phase, thus favoring electronic dimerization and the formation of a band gap. We then explore the effect of $V$ on the structural properties and the relative energies of the two phases, finding an insulating global energy minimum for the monoclinic phase, consistent with experimental observations. With increasing $V$, this minimum becomes deeper relative to the rutile structure, and the transition from the metallic to the insulating state becomes sharper. We also analyze the effect of applying the $+V$ correction either to all or only to selected vanadium-vanadium pairs, and both in the monoclinic as well as in the metallic rutile phase. Our results suggest that DFT$+V$ can indeed serve as a computationally inexpensive unbiased way of modeling VO$_2$ which is well suited for studies that, e.g., require large system sizes. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2406_08947 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Incorporating static intersite correlation effects in vanadium dioxide through DFT$+V$ Haas, Lea Mlkvik, Peter Spaldin, Nicola A. Ederer, Claude Materials Science Strongly Correlated Electrons We analyze the effects on the structural and electronic properties of vanadium dioxide (VO$_2$) of adding an empirical inter-atomic potential within the density-functional theory$+V$ (DFT$+V$) framework. We use the DFT$+V$ machinery founded on the extended Hubbard model to apply an empirical self-energy correction between nearest-neighbor vanadium atoms in both rutile and monoclinic phases, and for a set of structures interpolating between these two cases. We observe that imposing an explicit intersite interaction $V$ along the vanadium-vanadium chains enhances the characteristic bonding-antibonding splitting of the relevant bands in the monoclinic phase, thus favoring electronic dimerization and the formation of a band gap. We then explore the effect of $V$ on the structural properties and the relative energies of the two phases, finding an insulating global energy minimum for the monoclinic phase, consistent with experimental observations. With increasing $V$, this minimum becomes deeper relative to the rutile structure, and the transition from the metallic to the insulating state becomes sharper. We also analyze the effect of applying the $+V$ correction either to all or only to selected vanadium-vanadium pairs, and both in the monoclinic as well as in the metallic rutile phase. Our results suggest that DFT$+V$ can indeed serve as a computationally inexpensive unbiased way of modeling VO$_2$ which is well suited for studies that, e.g., require large system sizes. |
| title | Incorporating static intersite correlation effects in vanadium dioxide through DFT$+V$ |
| topic | Materials Science Strongly Correlated Electrons |
| url | https://arxiv.org/abs/2406.08947 |