Equilibrium Structures of Pyrazine, s-Triazine, and s-Tetrazine

In recent years, accurate equilibrium (re) structures have been determined for pyridine, pyridazine, and pyrimidine. Here, we report accurate re structures for the structurally related molecules pyrazine, s-triazine, and s-tetrazine, which were obtained using a composite approach based on explicitly correlated coupled-cluster theory (CCSD(T)-F12b) in conjunction with a large correlation-consistent basis set (cc-pCVQZ-F12) to take core–valence electron correlation into account. Additional terms were included to correct for the effects of iterative triple excitations (CCSDT), noniterative quadruple excitations (CCSDT(Q)), and scalar relativistic contributions (DKH2-CCSD(T)). The performance of this computational procedure was established through test calculations on selected small molecules. For s-triazine, accurate experimental ground-state rotational constants (B0) of the parent molecule and six D3h isotopologues from the literature were used to determine a semiexperimental re structure, which was found to be essentially identical with the best estimate from the current composite approach. The presently recommended equilibrium structural parameters of s-triazine are re(CH) = 108.17 pm, re(CN) = 133.19 pm, and θe(NCN) = 125.95°, with estimated uncertainties of ±0.10 pm and ±0.10°, respectively. The predicted equilibrium geometries for pyrazine and s-tetrazine are expected to be of the same accuracy. We recommend for pyrazine: re(CH) = 108.16 pm, re(CN) = 133.34 pm, re(CC) = 139.07 pm, θe(CNC) = 115.60°, and θe(HCC) = 120.75°; and for s-tetrazine: re(CH) = 107.95 pm, re(CN) = 133.39 pm, re(NN) = 132.01 pm, and θe(NCN) = 126.59°

Metallicity of the SrTiO3 surface induced by room temperature evaporation of alumina

It is shown that a metallic state can be induced on the surface of SrTiO3 crystals by the electron beam evaporation of oxygen deficient alumina or insulating granular aluminium. No special preparation nor heating of the SrTiO3 surface is needed. Final metallic or insulating states can be obtained depending on the oxygen pressure during the evaporation process. Photoconductivity and electrical field effect are also demonstrated.Comment: 8 pages, 3 figure

Catalytic reaction between adsorbed oxygen and hydrogen on Rh(111)

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Heralded Entanglement of Arbitrary Degree in Remote Qubits

Incoherent scattering of photons off two remote atoms with a Lambda-level structure is used as a basic Young-type interferometer to herald long-lived entanglement of an arbitrary degree. The degree of entanglement, as measured by the concurrence, is found to be tunable by two easily accessible experimental parameters. Fixing one of them to certain values unveils an analog to the Malus' law. An estimate of the variation in the degree of entanglement due to uncertainties in an experimental realization is given.Comment: published version, 4 pages and 2 figure

Network Mutual Information and Synchronization under Time Transformations

We investigate the effect of general time transformations on the phase synchronization (PS) phenomenon and the mutual information rate (MIR) between pairs of nodes in dynamical networks. We demonstrate two important results concerning the invariance of both PS and the MIR. Under time transformations PS can neither be introduced nor destroyed and the MIR cannot be raised from zero. On the other hand, for proper time transformations the timing between the cycles of the coupled oscillators can be largely improved. Finally, we discuss the relevance of our findings for communication in dynamical networks.Comment: 15 p

Electronic Mail: What Leaders Need to Know

Electronic mail (email) was introduced to the business environment in the early 1970\u27s. It was estimated that 130 million workers sent approximately 2.8 billion messages every day in 2000. Today, leaders all across the nation are installing email systems in their organizations. Many leaders understand the benefits but they do not understand the risks of implementing an email system. Some of the issues and risks to an organization may be: lack of rules for proper use, personal use on company time, perceptions of privacy, lack of confidentiality, and legal liability to the organization. Leaders may reduce the risk to their organization when installing en\u27iail by: training staff on the proper use of email, educating staff on the difference between written, oral and email communication, and implementing an organizational policy for the use of email. Leaders should understand all aspects of this bringing it into their organization