Self-consistent van der Waals density functional study of benzene adsorption on Si(100)

Abstract

The adsorption of benzene on the Si(100) surface is studied theoretically using the self-consistent van der Waals density functional (vdW-DF) method. The adsorption energies of two competing adsorption structures, butterfly (BF) and tight-bridge (TB) structures, are calculated with several vdW-DFs at saturation coverage. Our results show that recently proposed vdW-DFs with high accuracy all prefer TB to BF, in accord with more accurate calculations based on exact exchange and correlation within the random phase approximation. Detailed analyses reveal the important roles played by the molecule-surface interaction and molecular deformation upon adsorption, and we suggest that their precise description is prerequisite for accurate prediction of the most stable adsorption structure of organic molecules on semiconductor surfaces.

Hybrid image potential states in molecular overlayers on graphene

“…Correspondingly, 6 × 6 × 1, 4 × 4 × 1, and 3 × 3 × 1 k points are sampled in the Brillouin zone, respectively. The dispersion forces are included through the self-consistent [26][27][28][29] vdW-DF method [21,22] with the rev-vdW-DF2 functional [30][31][32][33][34][35]. The lattice constant of graphene obtained with the functional is 2.46Å, in good agreement with experiments [36].…”

Photoelectron Holographic Atomic Arrangement Imaging of Cleaved Bimetal-intercalated Graphite Superconductor Surface

“…Table 1 summarizes the bulk lattice constants331 and the present data for the cleaved surface compared with the values derived from the DFT calculation. As seen in Table 1, by employing recently proposed van der Waals density functional by Hamada, rev-vdW-DF232 along with Wu and Gygi’s separable form of the vdW kernel3334, the in-plane as well as inter-layer lattice constants of graphite and bulk KC 8 can be very well reproduced. Note that the in-plane and interlayer lattice parameters are larger than those of graphite and bulk KC 8 .…”

“…A recently proposed van der Waals density functional by Hamada, rev-vdW-DF232 was implemented with Wu and Gygi’s separable form of the vdW kernel3334. The inner electrons were replaced by ultrasoft-pseudopotentials and a plane wave basis set with cutoff energies of 36 Ry for wave functions and 400 Ry for charge density is employed.…”

Desorption dynamics of CO2 from formate decomposition on Cu(111)

“…12 Since the vdW interaction is important to describe the adsorption and chemical reaction of inert molecules, 13 we compare the Perdew-Burke-Ernzerhof (PBE) results with those obtained using vdW density functionals (vdW-DFs), i.e., the original vdW-DF (vdW-DF1), 14 optB86b-vdW, 15 and rev-vdW-DF2 16 functionals as implemented in the STATE code. 17 We also included the dispersion correction proposed by Grimme with PBE (PBE-D2). 18 We performed ab initio molecular dynamics (AIMD) simulations starting from the transition state (TS) structure of the formate decomposition process to gas phase CO 2 and adsorbed H to evaluate the translational and internal (rotational and vibrational) energies of desorbed CO 2 .…”