We assess the capabilities of eight popular density functional theory (DFT) functionals, in combination with several basis sets, as applied to calculations of vibrational sum frequency generation (SFG) spectra of the atmospherically relevant isoprene oxidation product trans-β-isoprene epoxydiol (IEPOX) and one of its deuterated isotopologues at the fused silica/vapor interface. We use sum of sq...

Chemical shift prediction plays an important role in the determination or validation of crystal structures with solid-state nuclear magnetic resonance (NMR) spectroscopy. One of the fundamental theoretical challenges lies in discriminating variations in chemical shifts resulting from different crystallographic environments. Fragment-based electronic structure methods provide an alternative to t...

The barriers of torsional isomerization of 13 substituted biphenyls, ranging from 7.4 to 44 kcal mol(-1), were calculated using 9 density functionals (the BP86 and B97D GGAs, the meta-GGA TPSS, hybrids B3LYP, PBE0, ωB97XD, BMK and M06-2X, as well as the double-hybrid B2PLYP), some combined with D and D3 corrections for dispersive interactions, and results were compared with experimental data. A...

The ability of different density functionals to describe the structural and energy differences between the high[5T2g:(t2g)4(eg)2] and low[1A1g:(t2g)6(eg)0] spin states of small octahedral ferrous compounds is studied. This work is an extension of our previous study of the hexaquoferrous cation, [Fe(H2O)6]2+, [J. Chem. Phys. 120, 9473 (2004)] to include a second compound—namely, the hexaminoferr...

In the continuous quest for improving TD-DFT methodologies as a tool to predict the photophysical features of solvated chromophores, we investigate two model regioisomers based on the 1,2,3-triazole moiety. Starting from their experimental absorption and emission spectra, key energy differences highlighting the main trends between the two isomers are extracted and used to gauge the accuracy of ...

This work is aimed at theoretical understanding of electronic absorption and emission energies of a series of substituted diphenyl butadiynes through an assessment of several TDDFT functionals and a detailed study of solvent effects on their ground and excited state structures and properties. Out of a series of functionals examined, the coulomb attenuated DFT functional CAM-B3LYP is found to be...

We systematically investigated iodine–metal and iodine–iodine bonding in van Koten’s pincer complex 19 modifications changing substituents and/or the transition metal with a PBE0–D3(BJ)/aug–cc–pVTZ/PP(M,I) model chemistry. As novel tool for quantitative assessment of bond strength these complexes we used local mode analysis, originally introduced by Konkoli Cremer, complemented NBO Bader’s QTAI...

We present a benchmark study of gas phase geometry optimizations in the excited states carbon monoxide, acetone, acrolein, and methylenecyclopropene using many-body Green’s functions theory within GW approximation Bethe–Salpeter equation (BSE) employing numerical gradients. scrutinize influence several typical approximations GW-BSE framework; we used one-shot G0W0 or eigenvalue self-consistent ...

Some of the most promising catalysts for water oxidation rely on crystalline and amorphous cobalt oxide nanoparticles. Density functional theory (DFT) calculations are routinely used to study the electronic and atomic structures of these materials as well as the thermodynamics and mechanisms of the electrochemical oxygen evolution reaction. The accuracy of these theoretical predictions has neve...

We report a study of intramolecular vibrational distribution (IVR) occurring in the electronic ground state of uracil (S0) in the gas phase, following photoexcitation in the lowest energy bright excited state (Sπ) and decay through the ethylene-like Sπ/S0 Conical Intersection (CI-0π). To this aim we have performed 20 independent ab initio molecular dynamics simulations starting from CI-0π (ten ...