Incorporating static intersite correlation effects in vanadium dioxide through <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mtext>DFT</mml:mtext><mml:mo>+</mml:mo><mml:mrow><mml:mi>V</mml:mi></mml:mrow></mml:math>

We analyze the effects on the structural and electronic properties of vanadium dioxide (<a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:msub><a:mi>VO</a:mi><a:mn>2</a:mn></a:msub></a:math>) due to adding an empirical interatomic potential within the density-functional <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mrow><b:mi>theory</b:mi><b:mo>+</b:mo><b:mi>V</b:mi></b:mrow></b:math> (<c:math xmlns:c="http://www.w3.org/1998/Math/MathML"><c:mrow><c:mi>DFT</c:mi><c:mo>+</c:mo><c:mi>V</c:mi></c:mrow></c:math>) framework. We use the <d:math xmlns:d="http://www.w3.org/1998/Math/MathML"><d:mrow><d:mi>DFT</d:mi><d:mo>+</d:mo><d:mi>V</d:mi></d:mrow></d:math> 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 <e:math xmlns:e="http://www.w3.org/1998/Math/MathML"><e:mi>V</e:mi></e:math> 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 bandgap. We then explore the effect of <f:math xmlns:f="http://www.w3.org/1998/Math/MathML"><f:mi>V</f:mi></f:math> 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 <g:math xmlns:g="http://www.w3.org/1998/Math/MathML"><g:mi>V</g:mi></g:math>, 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 <h:math xmlns:h="http://www.w3.org/1998/Math/MathML"><h:mrow><h:mo>+</h:mo><h:mi>V</h:mi></h:mrow></h:math> correction either to all or only to selected vanadium–vanadium pairs and both in the monoclinic as well as the metallic rutile phase. Our results suggest that <i:math xmlns:i="http://www.w3.org/1998/Math/MathML"><i:mrow><i:mi>DFT</i:mi><i:mo>+</i:mo><i:mi>V</i:mi></i:mrow></i:math> can indeed serve as a computationally inexpensive unbiased way of modeling <j:math xmlns:j="http://www.w3.org/1998/Math/MathML"><j:msub><j:mi>VO</j:mi><j:mn>2</j:mn></j:msub></j:math> which is well suited for studies that, e.g., require large system sizes. Published by the American Physical Society 2024