in this study, the effect of the secondary structure of the protein on the acid strength of three structures of random (r), alpha helix (α) and beta sheet (b) were investigated theoretically. these structures are related to the cationic amino acids of histidine and lysine in the polypeptide chain of eight-glycine residue. computational methods at the hf, b3lyp, x3lyp and m05-2x levels in the ga...

Hard-ligand, high-potential copper sites have been characterized in double mutants of Pseudomonas aeruginosa azurin (C112D/M121X (X = L, F, I)). These sites feature a small A(zz)(Cu) splitting in the EPR spectrum together with enhanced electron transfer activity. Due to these unique properties, these constructs have been called "type zero" copper sites. In contrast, the single mutant, C112D, ...

The electronic structure of the benzenium cation, [C6H7]+, the simplest intermediate of electrophilic aromatic substitution reactions, was analyzed in terms of the properties of electron densities obtained from multiconfigurational quantum theoretical methods. The indirect C-H coupling constants and the physical contributions to their values were calculated and rationalized in terms of the elec...

Electron-beam-induced deposition EBID is a versatile microand nanofabrication technique based on electron-induced dissociation of metal-carrying gas molecules adsorbed on a target. EBID has the advantage of direct deposition of three-dimensional structures on almost any target geometry. This technique has occasionally been used in focused electron-beam instruments, such as scanning electron mic...

Electron-electron interactions in general lead to both ground state and excited state confinement. We show, however, that in phenyl-substituted polyacetylenes electron-electron interactions cause enhanced delocalization of quasiparticles in the optically excited state from the backbone polyene chain into the phenyl groups, which in turn leads to enhanced confinement in the chain direction. This...

Based on ab initio molecular dynamics simulations, we show that small nanoclusters of about 1 nm size spontaneously generated in a low-temperature silane plasma do not possess tetrahedral structures, but are ultrastable. Apparently small differences in the cluster structure result in substantial modifications in their electric, magnetic, and optical properties, without the need for any dopants....

We have developed a new method, i.e., XLOGP3, for logP computation. XLOGP3 predicts the logP value of a query compound by using the known logP value of a reference compound as a starting point. The difference in the logP values of the query compound and the reference compound is then estimated by an additive model. The additive model implemented in XLOGP3 uses a total of 87 atom/group types and...

In the title compound, C(12)H(13)ClN(4)O(2), the triazole ring carries methyl and ethoxy-carbonyl groups, and is bound via a methyl-ene bridge to a chloro-pyridine unit. There is evidence for significant electron delocalization in the triazolyl system. Intra-molecular C-H⋯O and inter-molecular C-H⋯N hydrogen bonds stabilize the structure.

Performance modeling is important for implementing efficient parallel applications and runtime systems. The LogP model captures the relevant aspects of message passing in distributed-memory architectures. In this paper we describe an efficient method that measures LogP parameters for a given message passing platform. Measurements are performed for messages of different sizes, as covered by the ...