Role of van der Waals bonding in the layered oxideV2O5: First-principles density-functional calculations

Abstract

Sparse matter is characterized by regions with low electron density and its understanding calls for methods to accurately calculate both the van der Waals ͑vdW͒ interactions and other bonding. Here we present a first-principles density-functional theory ͑DFT͒ study of a layered oxide ͑V 2 O 5 ͒ bulk structure which shows charge voids in between the layers and we highlight the role of the vdW forces in building up material cohesion. The result of previous first-principles studies involving semilocal approximations to the exchangecorrelation functional in DFT gave results in good agreement with experiments for the two in-plane lattice parameters of the unit cell but overestimated the parameter for the stacking direction. To recover the third parameter we include the nonlocal ͑dispersive͒ vdW interactions through the vdW-DF method ͓M. Dion, H. Rydberg, E. Schröder, D. C. Langreth, and B. I. Lundqvist, Phys. Rev. Lett. 92, 246401 ͑2004͔͒ testing also various choices of exchange forms. We find that the transferable first-principles vdW-DF calculations stabilizes the bulk structure. The vdW-DF method gives results in fairly good agreement with experiments for all three lattice parameters.

Electronic structures of silver oxides

“…124,125) and V 2 O 5 . 72,126 To begin to assess this, we have considered the effect of dispersion corrections through the application of the GGA-D2 methodology of Grimme, [127][128][129] which adds dispersion corrections to the energy using a semiempirical pairwise force field. As the HSE06 approach is considerably more expensive than GGA, we initially trialled this only with the GGA approach.…”

Reconstruction of Low-Index α-V2O5 Surfaces

“…10,11 α-V 2 O 5 has a layered structure in the [010] direction. The layers are kept together by van der Waals interactions, 12 and α-V 2 O 5 can therefore be cleaved 13 or exfoliated 14−16 along the (010) facet. This means that the face formed by cleavage has the smallest surface energy and the largest surface area in a V 2 O 5 particle.…”

Stacking and band structure of van der Waals bonded graphane multilayers

“…For example, vdW binding can cause smaller amounts of net charge transfer within individual vdW-bonded fragments. 6 Also, wave function hybridization will certainly arise when material fragments approach one another, even if this hybridization does not significantly contribute to the binding itself (in purely dispersive interaction). Wave function hybridization and Pauli exclusion cause scattering of the surface-state electrons in physiosorption of acenes and quinones on Cu(111), even if there is no net charge transfer.…”