"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

Reactions of laser-ablated Y and La atoms with di-, tri-, and tetrahalomethanes in excess argon were investigated and the products were identified from their infrared matrix spectra, isotopic shifts, and comparison with frequencies computed by density functional theory. These DFT calculations also show that the primary products are planar and bridged methylidenes depending on the number of halogen atoms with no trace of insertion and products, parallel to the previous Sc results. While the C–M bond in the planar configuration has a considerable amount of -character, the observed bridged Y and La methylidene structures are indicative of strong electron donation to the empty d-orbtals on the metal center. These identified products reconfirm that the electronic structures of group 3 metals (d1s2) do not allow formation of the higher oxidation-state product in reaction with halomethanes. The preference of a group 3 metal product with more M–F bonds over those with more M–Cl bonds is also investigated.

Infrared Spectra and DFT Calcula­tions of Planar and Bridged Methyl­idene Intermediates in Reactions of Laser‐Ablated Yttrium and Lanthanum Atoms with Di‐, Tri‐, and Tetrahalomethanes

Matrix infrared study of low-energy electron and alkali cation impact on CCl4

Laser-ablated Be atoms, cations, and electrons were reacted with F2, ClF, Cl2, NF3, CCl4, CF2Cl2, HCl, DCl, and SiCl4 diluted in noble gases. The major products were the dihalides BeF2, BeClF, BeCl2, and the hydride chloride HBeCl, whose identities were confirmed by comparison with previous evaporative work, deuterium substitution, and vibrational frequency calculations. The matrix-isolated fundamental frequency of the BeF molecule is higher, and the frequency of BeCl is lower, than that determined for the gas-phase molecules. The BeF+ and BeCl+ cations formed strong dipole-induced dipole complexes in solid Ne, Ar, Kr, and Xe with stepwise increase in computed noble gas dissociation energies. Going down the family NgBeF+ and NgBeCl+ series (Ng = Ne, Ar, Kr, Xe) the Mulliken charges q(Be) decrease, while q(Ng) increases, and the dipole moments decrease, which suggests covalent bonding in the xenon species. We find that the largest intramatrix shift is Ne to Ar which follows the largest factor increase for ...

Infrared Spectroscopic and Electronic Structure Investigations of Beryllium Halide Molecules, Cations, and Anions in Noble Gas Matrices

UF{sub 6}, WF{sub 6}, MoF{sub 6}, and SF{sub 6} have been codeposited with hydrogen fluoride in excess argon at 12 K. The FTIR spectra of UF{sub 6} and HF revealed a strong UF{sub 6}-HF complex absorption at 3,848 cm{sup {minus}1} along with a weak, broad band at 3,903 cm{sup {minus}1} due to the UF{sub 6}-FH complex. Only one 1:2 complex with a UF{sub 6}-H{sub a}F-H{sub b}F arrangement was detected at higher HF concentrations and sample annealings. Similarly, the HF interaction with tungsten hexafluoride formed two 1:1 complexes. However, the 3,884-cm{sup {minus}1} band due to the anti-hydrogen-bonded complex WF{sub 6}-FH was considerably stronger than the WF{sub 6}-FH{sub b}-FH{sub a} structure. The band positions and relative intensities for the MoF{sub 6} complexes with HF and DF were very comparable to their WF{sub 6} counterparts.

Infrared spectra of uranium hexafluoride, tungsten hexafluoride, molybdenum hexafluoride, and sulfur hexafluoride complexes with hydrogen fluoride in solid argon

Lester Andrews

Papers

Infrared Spectra and DFT Calculations of Planar and Bridged Methylidene Intermediates in Reactions of Laser‐Ablated Yttrium and Lanthanum Atoms with Di‐, Tri‐, and Tetrahalomethanes

Matrix infrared study of low-energy electron and alkali cation impact on CCl4

Infrared Spectroscopic and Electronic Structure Investigations of Beryllium Halide Molecules, Cations, and Anions in Noble Gas Matrices

Infrared spectra of uranium hexafluoride, tungsten hexafluoride, molybdenum hexafluoride, and sulfur hexafluoride complexes with hydrogen fluoride in solid argon

Absorption spectra and rearrangements of halotoluene parent cations in solid argon

Lester Andrews

Papers

Infrared Spectra and DFT Calcula­tions of Planar and Bridged Methyl­idene Intermediates in Reactions of Laser‐Ablated Yttrium and Lanthanum Atoms with Di‐, Tri‐, and Tetrahalomethanes

Matrix infrared study of low-energy electron and alkali cation impact on CCl4

Infrared Spectroscopic and Electronic Structure Investigations of Beryllium Halide Molecules, Cations, and Anions in Noble Gas Matrices

Infrared spectra of uranium hexafluoride, tungsten hexafluoride, molybdenum hexafluoride, and sulfur hexafluoride complexes with hydrogen fluoride in solid argon

Absorption spectra and rearrangements of halotoluene parent cations in solid argon

Infrared Spectra and DFT Calculations of Planar and Bridged Methylidene Intermediates in Reactions of Laser‐Ablated Yttrium and Lanthanum Atoms with Di‐, Tri‐, and Tetrahalomethanes