"Chemists familiar with conventional quantum mechanics will applaud and benefit greatly from this particularly instructive, thorough and clearly written exposition of density functional theory: its basis, concepts, terms, implementation, and performance in diverse applications. Users of DFT for structure, energy, and molecular property computations, as well as reaction mechanism studies, are guided to the optimum choices of the most effective methods. Well done!" Paul von RaguE Schleyer "A conspicuous hole in the computational chemist's library is nicely filled by this book, which provides a wide-ranging and pragmatic view of the subject.[...It] should justifiably become the favorite text on the subject for practioneers who aim to use DFT to solve chemical problems." J. F. Stanton, J. Am. Chem. Soc. "The authors' aim is to guide the chemist through basic theoretical and related technical aspects of DFT at an easy-to-understand theoretical level. They succeed admirably." P. C. H. Mitchell, Appl. Organomet. Chem. "The authors have done an excellent service to the chemical community. [...] A Chemist's Guide to Density Functional Theory is exactly what the title suggests. It should be an invaluable source of insight and knowledge for many chemists using DFT approaches to solve chemical problems." M. Kaupp, Angew. Chem.

A Chemist's Guide to Density Functional Theory

A scheme that reduces the calculations of ground-state properties of systems of interacting particles exactly to the solution of single-particle Hartree-type equations has obvious advantages. It is not surprising, then, that the density functional formalism, which provides a way of doing this, has received much attention in the past two decades. The quality of the energy surfaces calculated using a simple local-density approximation for exchange and correlation exceeds by far the original expectations. In this work, the authors survey the formalism and some of its applications (in particular to atoms and small molecules) and discuss the reasons for the successes and failures of the local-density approximation and some of its modifications.

The density functional formalism, its applications and prospects

The halogen bond occurs when there is evidence of a net attractive interaction between an electrophilic region associated with a halogen atom in a molecular entity and a nucleophilic region in another, or the same, molecular entity. In this fairly extensive review, after a brief history of the interaction, we will provide the reader with a snapshot of where the research on the halogen bond is now, and, perhaps, where it is going. The specific advantages brought up by a design based on the use of the halogen bond will be demonstrated in quite different fields spanning from material sciences to biomolecular recognition and drug design.

The Halogen Bond

The detection methods and generation mechanisms of the intrinsic reactive oxygen species (ROS), i.e., superoxide anion radical (•O2–), hydrogen peroxide (H2O2), singlet oxygen (1O2), and hydroxyl radical (•OH) in photocatalysis, were surveyed comprehensively. Consequently, the major photocatalyst used in heterogeneous photocatalytic systems was found to be TiO2. However, besides TiO2 some representative photocatalysts were also involved in the discussion. Among the various issues we focused on the detection methods and generation reactions of ROS in the aqueous suspensions of photocatalysts. On the careful account of the experimental results presented so far, we proposed the following apprehension: adsorbed •OH could be regarded as trapped holes, which are involved in a rapid adsorption–desorption equilibrium at the TiO2–solution interface. Because the equilibrium shifts to the adsorption side, trapped holes must be actually the dominant oxidation species whereas •OH in solution would exert the reactivity...

Generation and Detection of Reactive Oxygen Species in Photocatalysis

: The unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio. Harmonic force fields are obtained using Density Functional Theory (DFT), MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set. DFT calculations use the Local Spin Density Approximation (LSDA), BLYP, and Becke3LYP (B3LYP) density functionals. Mid-IR spectra predicted using LSDA, BLYP, and B3LYP force fields are of significantly different quality, the B3LYP force field yielding spectra in clearly superior, and overall excellent, agreement with experiment. The MP2 force field yields spectra in slightly worse agreement with experiment than the B3LYP force field. The SCF force field yields spectra in poor agreement with experiment.The basis set dependence of B3LYP force fields is also explored: the 6-31G* and TZ2P basis sets give very similar results while the 3-21G basis set yields spectra in substantially worse agreements with experiment. jg

Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields

Absorption spectra and photochemical rearrangement of cycloheptatriene cation to toluene cation in solid argon

Methane and methyl halide activation by Sc atoms: Infrared spectra and DFT calculations for the CH3–ScX and CH2–ScHX complexes

Proton beam radiolysis of matrix samples. New technique for infrared spectroscopic study of charged molecular intermediates

Reactions of laser-ablated Sc, Ti, V, Cr, and Mn with NO in excess neon give the same major products found in excess argon with several interesting differences. The argon-to-neon matrix shifts range from +43 cm-1 for the small Sc[NO]+ cation to −5 cm-1 for Sc[NO]. The lower polarizability of neon leads to a slower condensation rate and allows more reagent diffusion and reaction under the conditions of these experiments, and as a result, higher nitrosyls are observed on condensation in excess neon. Another consequence of the slower condensation rate of neon is the inability to trap as much of the side-bound M[NO] precursor relative to the NMO insertion product:  higher yields of M[NO] species are trapped in solid argon. An advantage of the greater inertness of neon is its ability to trap cations with less perturbation than argon. Model calculations show that argon interacts more strongly with Sc[NO]+ than with neon:  the ArSc[NO]+ species is stable and has a lower N−O stretching frequency than NeSc[NO]+. N...

Infrared Spectra and Density Functional Calculations for Early First-Row Transition Metal Nitrosyls in Solid Neon

Laser-ablated boron atoms react with methyl fluoride in an argon stream to form two major products:  CH2BF and CHBF. In similar reactions of boron with methyl chloride and methyl bromide, both CH2BX and CHBX are also observed, as well as the primary insertion products, CH3BCl and CH3BBr, respectively. Infrared spectra of isotopic combinations of B and CH3X and density functional theory frequency calculations provide evidence for the product identification. Both products form via insertion into the C−X bond followed by loss of one or two H atoms for all reactions. Comparisons are made with the products of the reactions of B with C2H6, CH3NH2, and CH3OH, all of which are isoelectronic with CH3F. The calculations not only predict the vibrational frequencies exceptionally well, but also predict that there is no dative bonding in either CH2BX or CHBX, despite the empty p-orbital on B and the filled p-orbitals on the halogen atom.

Reactions of Laser-Ablated Boron Atoms with Methyl Halides in Excess Argon. Infrared Spectra and Density Functional Theory Calculations on CH3BX, CH2BX, and CHBX (X = F,Cl,Br)

Lester Andrews

Papers

Absorption spectra and photochemical rearrangement of cycloheptatriene cation to toluene cation in solid argon

Methane and methyl halide activation by Sc atoms: Infrared spectra and DFT calculations for the CH3–ScX and CH2–ScHX complexes

Proton beam radiolysis of matrix samples. New technique for infrared spectroscopic study of charged molecular intermediates

Infrared Spectra and Density Functional Calculations for Early First-Row Transition Metal Nitrosyls in Solid Neon

Reactions of Laser-Ablated Boron Atoms with Methyl Halides in Excess Argon. Infrared Spectra and Density Functional Theory Calculations on CH3BX, CH2BX, and CHBX (X = F,Cl,Br)