Phototoxicity is of increasing concern since modern lifestyle is often associated with exposure to sunlight. Therefore characterizing the phototoxic potential of a compound early in its development is of utmost interest, especially for compounds likely to undergo sunlight exposure in skin. Traditioanly the phototoxic effect is modeled by using the E HOMO -E LUMO gap (energy difference between t...

We examined the published data for the binding affinity of typical ligands to the α-subtype of the human estrogen receptor with use of an approximate molecular orbital method applicable to interacting molecular clusters. An ab initio procedure for “molecular fragments” proposed recently to deal with such macromolecules as proteins was applied to the molecular orbital calculations. The receptor ...

On the basis of electronic structure calculations and molecular orbital analysis, we offer a physical explanation of the observed large decrease (0.9 eV) in ionization energies (IE) in going from hydroxymethyl to hydroxyethyl radical. The effect is attributed to hyperconjugative interactions between the sigma CH orbitals of the methyl group in hydroxyethyl, the singly occupied p orbital of carb...

INTRODUCTION The idea of Möbius aromaticity was first proposed by Heilbronner in 1964. He postulated that a molecule could gain Möbius aromatic stabilization if the nuclear framework were twisted so the porbitals composing the π-system would contain an odd number of nodes. To introduce a node in the orbitals, Heilbronner theorized that a series of p-orbitals could itself be twisted by contortin...

We present our perspective and goals on highperformance computing for nanoscience in accordance with the global trend toward “peta-scale computing.” After reviewing our results obtained through the grid-enabled version of the fragment molecular orbital method (FMO) on the grid testbed by the Japanese Grid Project, National Research Grid Initiative (NAREGI), we show that FMO is one of the best c...

Inhibition efficiencies of three amine derivatives (Diethylenetriamine (I), Triethylenetetramine (II), and Pentaethylenehexamine (III)) have been studied on corrosion of carbon steel using density functional theory (DFT) method in gas phase. Quantum chemical parameters such as EHOMO (highest occupied molecular orbital energy), ELUMO (lowest unoccupied molecular orbital energy), hardness (η), po...

We investigated electron attachment to three dihalobenzene molecules, bromochlorobenzene (BCB), bromoiodobenzene (BIB) and chloroiodobenzene (CIB), by molecular beam photoelectron spectroscopy. The most prominent product of electron attachment in the anion mass spectra was the atomic fragment of the less electronegative halogen of the two, i.e., Br(-) for BCB and I(-) for BIB and CIB. Photoelec...