In this work the ISOL24 database of isomerization energies of large organic molecules presented by Huenerbein et al. [Phys. Chem. Chem. Phys., 2010, 12, 6940] is updated, resulting in the new benchmark database called ISOL24/11, and this database is used to test 50 electronic model chemistries. To accomplish the update, the very expensive and highly accurate CCSD(T)-F12a/aug-cc-pVDZ method is f...

Zero-point vibrationally averaged (rg 0 ) structures were computed at the PBE0/SDD/631G* level for the [Pt 35 Cln 37 Cl5-n(H2 18 O)]  (n=0-5), cis-Pt 35 Cln 37 Cl(4-n)(H2 18 O)(H2 16 O) (n=0-4), fac-[Pt 35 Cln 37 Cl(3-n)(H2 18 O)(H2 16 O)2]  (n=0-3), [Pt 35 Cln 37 Cl5-n( 16/18 OH)] 2 (n=0-5), cis-[Pt 35 Cln 37 Cl(4-n)( 16/18 OH)2] 2(n=0-4), fac-[Pt 35 Cln 37 Cl(3-n)( 16/18 OH)3]  (n=0-3), ...

State-of-the-art generalized gradient approximation (GGA) (PBE, OPBE, RPBE, OLYP, and HCTH), meta-GGA (VSXC and TPSS), and hybrid (B3LYP, B3LYP*, O3LYP, and PBE0) functionals are compared for the determination of the structure and the energetics of the D3 [Co(bpy)3](2+) complex in the (4)A2 and (4)E trigonal components of the high-spin (4)T1g([Formula: see text]  [Formula: see text] ) state and...

We analyze the basic structural units of simple reconstructions of the (1 1 1) surface of SrTiO3 using density functional calculations. The prime focus is to answer three questions: what is the most appropriate functional to use; how accurate are the energies; what are the dominant low-energy structures and where do they lie on the surface phase diagram. Using test calculations of representativ...

Density functionals are often used in ab initio thermochemistry to provide optimized geometries for single-point evaluations at a high level and supply estimates of anharmonic zero-point energies (ZPEs). Their use is motivated by relatively accuracy modest computational expense, but thorough assessment geometry-related error seems be lacking. We have benchmarked 53 density functionals, focusing...

We present the CHAL336 benchmark set-the most comprehensive database for assessment of chalcogen-bonding (CB) interactions. After careful selection suitable systems and identification three high-level reference methods, set comprises 336 dimers each consisting up to 49 atoms covers both σ- π-hole interactions across four categories: chalcogen-chalcogen, chalcogen-π, chalcogen-halogen, chalcogen...

The nonrelativistic ``Ramsey-Flygare relationship'' is the most used procedure to obtain semiexperimental nuclear magnetic resonance (NMR) absolute shieldings by a correspondence between NMR ($\mathbit{\ensuremath{\sigma}}$) and spin-rotation constants ($\mathbit{M}$). One of its generalizations relativistic framework known as M-V model, which was proposed few year ago some authors present work...

Density functional theory (DFT) is the only quantum-chemical avenue for calculating thermochemical/kinetic properties of large polycyclic aromatic hydrocarbons (PAHs) such as graphene nanoflakes. Using CCSD(T)/CBS PAH isomerization energies, we find that all generalized gradient approximation (GGA) and meta GGA DFT functionals have severe difficulties in describing isomerization energies in PAH...

The transport and bioavailability of sulphate in soils are significantly affected by adsorption reactions at the mineral–H2O interface. Therefore, an understanding of the mechanisms and kinetics of sulphate adsorption is of fundamental importance in soil chemistry. In this investigation, the binding geometries of bidentate bridging and monodentate sulphate complexes at the Fe (hydr)oxide–H2O in...

Multiple mechanisms of backbiting and b-scission reactions in free-radical polymerization of methyl acrylate are modeled using different levels of theory, and the rigid-rotor harmonicoscillator (RRHO) and hindered-rotor (HR) approximations. We identify the most cost-effective computational method(s) for studying the reactions and assess the effects of different factors (e.g., functional type an...