We report linear-response kinetic-energy density functionals, which show significant improvement over the Wang-Teter, Perrot, Smargiassi-Madden, Wang-Govind-Carter yet still maintain $\mathcal{O}(N\mathrm{ln}N)$ scaling. Numerical tests that these contain a double-density-dependent kernel, can reproduce Kohn-Sham results almost exactly for several aluminum bulk phases. further with sensible choice of uniform background density, energies formation low-index surfaces, where variations are very...

A first-principles embedding theory that combines the salient features of density functional (DFT) and traditional quantum chemical methods is presented. The method involves constructing a DFT-based potential then using it as one-electron operator within very accurate ab initio calculation. We demonstrate how DFT calculations can be systematically improved via this procedure. scheme tested two closed shell systems, toy model Li2Mg2, experimentally well characterized CO/Cu(111) system. Our...

We extend our recently reported embedding theory [J. Chem. Phys. 110, 7677 (1999)] to calculate not only improved descriptions of ground states, but now also localized excited states in a periodically infinite condensed phase. A local region the solid is represented by small cluster for which high quality quantum chemical calculations are performed. The interaction with extended phase taken into account an effective potential. This potential calculated periodic density functional (DFT) and...

We present an improvement over the Wang-Teter, Perrot, and Smargiassi-Madden kinetic-energy functionals without going beyond linear-response theory introducing a density-dependent kernel. The improved were tested on bulk aluminum, excellent results obtained. Accurate density-functional calculations using new systems larger than one can study by traditional Kohn-Sham methods are demonstrated.

The adsorption of small gaseous molecules to the metal center in Pt-doped (5,5) single-walled carbon nanotubes has been explored within density functional theory. A model system consisting a single Pt atom residing middle nanotube with capping H atoms is used for our investigation. For all gases studied, overall process was found be exothermic, where affinity strongly depended on orientation molecule. By examining states and molecular orbitals these nanotube−adsorbate complexes comparison...

The Staudinger reactions of substituted phosphanes and azides have been investigated by using density functional theory. Four different initial reaction mechanisms found. All systems studied go through a cis-transition state rather than trans-transition or one-step transition state. pathway the phosphorus atom attacking nitrogen is always unfavorable energetically. Depending on substituents azide phosphane, mechanism with lowest barrier can be classified into three categories: (1) like...

[Chemical reaction: See text] Conjugated, shape-persistent macrocycles based on [3 + 3] Schiff-base condensation are of interest for supramolecular materials. In an effort to develop new discotic liquid crystals these compounds, a series with peripheral alkoxy groups varying length have been prepared. The synthesis and mechanism formation probed by isolation oligomeric intermediates. A single-crystal X-ray diffraction study one macrocycle revealed nonplanar, strongly hydrogen-bonded...

The histone lysine monomethyltransferase SETD8 is an epigenetic regulator of cell cycle progression. Nahuoic acid A (1), a polyketide produced in culture by Streptomyces sp. obtained from tropical marine sediment, the first known selective SAM-competitive inhibitor SETD8. structure nahuoic (1) has been elucidated chemical transformation and detailed analysis spectroscopic data.

Four new sesterterpenoids, ansellone B (4), phorbadione (5), secoepoxyansellone A (6), and alotaketal C (7), have been isolated from specimens of the sponge Phorbas sp. collected in British Columbia. Ansellone (4) has an unprecedented heterocyclic skeleton featuring oxocane ring, (6) is first example degraded "secoansellane" sesterterpenoid carbon skeleton. Alotaketal (7) activator cAMP signaling HEK cells.

The lack of accurate transferable local pseudopotentials represents one the remaining barriers to general application orbital-free density functional theory (OF-DFT, a linear scaling technique). Here we report method generate high quality ab initio (LPS's) for use in condensed matter DFT calculations. We exploit first Hohenberg-Kohn theorem, which states that external potential is one-to-one mapped ground-state electron density. By employing scheme inverting Kohn-Sham (KS) equations due Wang...

After carefully analyzing the Kamlet-Jacobs (K-J) equations and structural traits of well-known explosives, hexahydro-1,3,5-trinitro-1,3,5-triazin (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), hexanitrohexaazaisowurtizitane (CL-20), diverse nitramine explosives including linear (Models IAn, IBn, ICn), cyclic (Model IIn), caged IIIAn IIIBn) molecules were designed by incorporating various number (n) -CH2NNO2- unit studied using B3LYP/6-31G* B3PW91/6-31G** methods density...

Two new styryl lactone derivatives, goniothapic acids A (1) and B (2), 18 known compounds, were isolated from the twig leaf extracts of Goniothalamus tapis Miq. The structures compounds characterised by spectroscopic methods HRESITOFMS. Their absolute configuration was established comparing experimental calculated ECD spectra. Eleven evaluated for their α-glucosidase inhibitory activity. Of these, (−)-goniothalamin (5) oldhamactam (16) showed best activity with IC50 values 54.8 57.9 µM, respectively.

Easily prepared and highly modular organic amide proligands have been used to synthesize a series of new bis(amidate)-bis(amido) Ti Zr complexes via protonolysis. These structurally characterized by NMR spectroscopy X-ray crystallography. The solid-state molecular structures these indicate that the amidate ligands bind metal centers in an exclusively bidentate fashion, resulting discrete monomeric species. Geometric isomerism species is dependent upon steric characteristics utilized...

Based on the corrected Hohenberg-Kohn-Sham total energy density functional [Y. A. Zhang and Y. Wang, J. Chem. Phys. 130, 144116 (2009)], we have developed two linear-expansion shooting techniques (LIST)- direct LIST (LISTd) indirect (LISTi), to accelerate convergence of self-consistent field (SCF) calculations. Case studies show that overall LISTi is most robust efficient algorithm for accelerating SCF convergence, whereas LISTd advantageous in early stage an process. More importantly,...

We have studied single-walled carbon nanotubes (SWCNTs) doped with transition metal (TM) atoms both exo and endo doping configurations. The electronic geometric properties of these TM-doped SWCNTs were calculated within density functional theory. It was found that the endo-doped are less stable than exo-doped counterparts due to large strain deformation in nanotubes. On basis partial charge analysis, localized net distributions, whereas spin densities Sc-, Co-, Cu-doped delocalized over...

The ozonization at the vacancy defect site of single-walled carbon nanotube has been studied by static quantum mechanics and atom-centered density matrix propagation based ab initio molecular dynamics within a two-layered ONIOM approach. Among five different reaction pathways defect, involving unsaturated active atom is most probable pathway, where ozone undergoes fast dissociation 300 K. Complementary to experiments, our work provides microscopic understanding nanotube.

Interactions between atomic Pt and pristine or Stone−Wales-defective (5,5) single-walled boron nitride nanotubes (BNNTs) were studied using density functional theory (DFT) with truncated nanotube models. The binding energy of on a BNNT is about 20 kcal/mol little dependency the site. On other hand, when Stone−Wales (SW) defect presented, preferentially inserted B−B bond in SW region large 58 kcal/mol. an SW-defective BNNT, Pt, even placed away from site, may eventually (thermodynamically)...

Extracts of laboratory cultures the fungus Penicilium purpurogenum obtained from rotting fruit tree Averrhoa bilimbi growing in Sri Lanka have yielded 10 new meroterpenoids, dhilirolides E-N (5-14). The structures been elucidated by analysis spectroscopic data and a single-crystal X-ray diffraction dhilirolide L (12). Dhilirolides A-N (1-14) represent four unprecedented rearranged dhilirane, isodhilirane, 14,15-dinordhilirane, 23,24-dinorisodhilirane meroterpenoid carbon skeletons. Stable...

The structures of the (5,5) single-walled carbon nanotube (SWCNT) segments with hemispheric cages capped at ends (SWCNT rod) and Pt-doped SWCNT rods have been studied within density functional theory. Our theoretical studies find that introduce localized states on caps. cap-Pt-doped can be utilized as sensors because sensitivity doped Pt atom. also used catalysts, where atom serves enhanced active center SWCNT. adsorptions C2H4 H2 in reveal different adsorption characteristics. all three...