Well-ordered and oriented monolayers of conjugated organic molecules can offer new perspectives on surface bonding. We will demonstrate the importance of the momentum distribution, or symmetry, of the adsorbate molecules' π orbitals in relation to the states available for hybridization at the metal surface. Here, the electronic band structure of the first monolayer of sexiphenyl on Cu(110) has ...

Ab initio and density functional theory-based computations are performed to investigate the structure and stability of H3SiNgNSi and HSiNgNSi compounds (Ng = Xe, Rn). They are thermochemically unstable with respect to the dissociation channel producing Ng and H3SiNSi or HSiNSi. However, they are kinetically stable with respect to this dissociation channel having activation free energy barriers ...

We consider the structural similarity of small gallium clusters to the bulk structure of α-gallium, which has been previously described as a molecular metal, via density functional theory-based computations. Previous calculations have shown that the tetramer, the hexamer, and the octamer of gallium are all structurally similar to the α-phase. We perform an analysis of the bonding in these clust...

A new methodology to obtain reactivity indices has been defined. This is based on reactivity functions such as the Fukui function or the dual descriptor and makes it possible to project the information of reactivity functions over molecular orbitals instead of the atoms of the molecule (atomic reactivity indices). The methodology focuses on the molecule's natural bond orbitals (bond reactivity ...

Nitrosylcobalamin (NOCbl) is readily formed when Co(II)balamin reacts with nitric oxide (NO) gas. NOCbl has been implicated in the inhibition of various B12-dependent enzymes, as well as in the modulation of blood pressure and of the immunological response. Previous studies revealed that among the known biologically relevant cobalamin species, NOCbl possesses the longest bond between the Co ion...

Density functional theory is used to study the mechanism of the title reaction, one of the first catalytic asymmetric 6π-electrocyclizations observed experimentally. The benzylideneacetone-derived phenyl hydrazone is chosen as model substrate for the cyclization reaction, both in the protonated (A) and unprotonated (B) form, while the isoelectronic carbon analogue, 1,5-diphenylpentadienyl anion...

Semiclassical simulations are reported for the dynamics of the photocyclization of cis-stilbene, leading to the formation of 4a,4bdihydrophenanthrene. Photo-excited cis-stilbene rotates about its vinyl and vinyl–phenyl bonds simultaneously. The structural changes result in a series of strong couplings between the highest occupied molecular orbital and the lowest unoccupied molecular orbital. Th...

Given a finite set T of maps on a finite ring R, we look at the finite simple graph G = (V,E) with vertex set V = R and edge set E = {(a, b) | ∃t ∈ T, b = t(a), and b 6= a}. An example is when R = Zn and T consists of a finite set of quadratic maps Ti(x) = x 2 + ai. Graphs defined like that have a surprisingly rich structure. This holds especially in an algebraic setup when T is generated by po...

In this response to the preceding paper by Bader, we show that the core arguments and statements presented in the latter are flawed. We argue that it is insufficient for a model of the chemical bond to be rooted in quantum mechanics. A good model must in addition provide insight and possess predictive power. Our molecular orbital (MO) model of the chemical bond, in particular, the associated en...