We report a systematic study of the weak chemical bond between two benzene molecules. We first show that it is possible to obtain a very good description of the C(2) dimer and the benzene molecule by using pseudopotentials for the chemically inert 1s electrons and a resonating valence bond wave function as a variational ansatz, expanded on a relatively small Gaussian basis set. We employ an imp...

Strong or low-barrier hydrogen bonds have often been proposed in proteins to explain enzyme catalysis and proton-transfer reactions. So far (1)H chemical shifts and scalar couplings have been used as the main NMR spectroscopic signatures for strong H-bonds. In this work, we report simultaneous measurements of (15)N and (1)H chemical shifts and N-H bond lengths by solid-state NMR in (15)N-labele...

The correlation between chemical structure and dynamics has been explored in a series of molecules with increasing structural complexity in order to investigate its influence on bond cleavage reaction times in a photodissociation event. Femtosecond time-resolved velocity map imaging spectroscopy reveals specificity of the ultrafast carbon-iodine (C-I) bond breakage for a series of linear (unbra...

Second-order nonlinear optical properties of Mg-doped lithium niobate single crystals are quantitatively studied from the chemical bond viewpoint. The results show that the secondorder nonlinear optical response of Mg-doped LiNbO3 single crystals at 1079 nm decreases linearly with increasing Mg concentration in the crystal. This linear correlation is quantitatively evaluated in the current work.

A previous theory of separation of motions of core and valence fractions of electrons in a molecule [J. R. Mohallem et al., Chem. Phys. Lett. 501, 575 (2011)] is invoked as basis for the useful concept of Atoms-in-Molecules (AIM) in the stockholder scheme. The output is a new tool for the analysis of the chemical bond that identifies core and valence electron density fractions (core-valence sto...

One of the oldest and most useful concepts in chemistry is that of the chemical bond. While the current understanding of a chemical bond has become relatively sophisticated, the original representation of a single bond between two atoms by a line and a double bond by two lines, dates from Odling (1860) and Kekule (1861). Although the theory of the chemical bond has enjoyed considerable developm...

In this discussion, we show that a static definition of a 'bond' is not viable by looking at a few examples for both inter- and intra-molecular hydrogen bonding. This follows from our earlier work (Goswami and Arunan, Phys. Chem. Chem. Phys. 2009, 11, 8974) which showed a practical way to differentiate 'hydrogen bonding' from 'van der Waals interaction'. We report results from ab initio and ato...

A formamide molecule is allowed to form a CH O H-bond with a glycine dipeptide in both its C5 and C7 internal conformations. As this intermolecular H-bond is elongated, the contraction of the CAH covalent bond is monitored, as is its vibrational stretching frequency and intensity, along with NMR chemical shifts of the atoms involved in the H-bond. The degree of shortening of the CAH bond become...

The mathematical representation of chemical bonds in molecules is discussed. The molecule is viewed as a system of weakly interacting chemical bonds. The intrabond problems and the averaged electrostatic interbond interactions are handled at the . zeroth order, while the small interbond delocalization and dispersion effects are taken into account on the basis of the perturbation theory. A speci...