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We suggest that in the recent papers [J. Chem. Phys. 113, 2873 (2000)] and [J. Chem. Phys. 115, 11299 (2001)] an incorrect expression was used to obtain the diffusion coefficient of water in fully hydrated vermiculite clay from the Q dependence of the quasielastic neutron scattering data. This has led to underestimating the mean square jump length and the translational diffusion coefficient by a factor of 3. We discuss the correct way to extract the diffusion parameters and their properly estimated values. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Complete and reliable knowledge of the ammonia spectrum is needed to enable the analysis and interpretation of astrophysical and planetary observations. Ammonia has been observed in the interstellar medium up to J=18 and more highly excited transitions are expected to appear in hot exoplanets and brown dwarfs. As a result, there is considerable interest in observing and assigning the high J (rovibrational) spectrum. In this work, numerous spectroscopic techniques were employed to study its high J transitions in the ground and ν2=1 states. Measurements were carried out using a frequency multiplied submillimeter spectrometer at Jet Propulsion Laboratory (JPL), a tunable far-infrared spectrometer at University of Toyama, and a high-resolution Bruker IFS 125 Fourier transform spectrometer (FTS) at Synchrotron SOLEIL. Highly excited ammonia was created with a radiofrequency discharge and a dc discharge, which allowed assignments of transitions with J up to 35. One hundred and seventy seven ground state and ν2=1 inversion transitions were observed with microwave accuracy in the 0.3-4.7 THz region. Of these, 125 were observed for the first time, including 26 ΔK=3 transitions. Over 2000 far-infrared transitions were assigned to the ground state and ν2=1 inversion bands as well as the ν2 fundamental band. Of these, 1912 were assigned using the FTS data for the first time, including 222 ΔK=3 transitions. The accuracy of these measurements has been estimated to be 0.0003-0.0006 cm-1. A reduced root mean square error of 0.9 was obtained for a global fit of the ground and ν2=1 states, which includes the lines assigned in this work and all previously available microwave, terahertz, far-infrared, and mid-infrared data. The new measurements and predictions reported here will support the analyses of astronomical observations by high-resolution spectroscopy telescopes such as Herschel, SOFIA, and ALMA. The comprehensive experimental rovibrational energy levels reported here will permit further refinement of the potential energy surface to improve ammonia ab initio calculations and facilitate assignment of new high-resolution spectra of hot ammonia. [ABSTRACT FROM AUTHOR]

We investigate the size extensivity of the direct optimized effective potential procedure of Yang and Wu [Phys. Rev. Lett. 89, 143002 (2002)]. The choice of reference potential within the finite basis construction of the local Kohn–Sham potential can lead to a method that is not size extensive. Such a situation is encountered when one employs the Fermi–Amaldi potential, which is often used to enforce the correct asymptotic behavior of the exact exchange-correlation potential. The size extensivity error with the Fermi–Amaldi reference potential is shown to behave linearly with the number of electrons in the limit of an infinite number of well separated monomers. In practice, the error tends to be rather small and rapidly approaches the limiting linear behavior. Moreover, with a flexible enough potential basis set, the error can be decreased significantly. We also consider one possible reference potential, constructed from the van Leeuwen–Baerends potential, which provides a size extensive implementation while also enforcing the correct asymptotic behavior. [ABSTRACT FROM AUTHOR]

In a recent article [M. Merolle et al., Proc. Natl. Acad. Sci. U.S.A. 102, 10837 (2005)], it was argued that dynamic heterogeneity in d-dimensional glass formers is a manifestation of an order-disorder phenomenon in the d+1 dimensions of space time. By considering a dynamical analog of the free energy, evidence was found for phase coexistence between active and inactive regions of space time, and it was suggested that this phenomenon underlies the glass transition. Here we develop these ideas further by investigating in detail the one-dimensional Fredrickson-Andersen (FA) model, in which the active and inactive phases originate in the reducibility of the dynamics. We illustrate the phase coexistence by considering the distributions of mesoscopic space-time observables. We show how the analogy with phase coexistence can be strengthened by breaking microscopic reversibility in the FA model, leading to a nonequilibrium theory in the directed percolation universality class. [ABSTRACT FROM AUTHOR]

Equilibrium molecular dynamics calculations have been performed for the liquid crystal molecule n-4-(trans-4-n-pentylcyclohexyl)benzonitrile (PCH5) using a fully atomistic model. Simulation data have been obtained for a series of temperatures in the nematic phase. The simulation data have been used to calculate the flexoelectric coefficients es and eb using the linear response formalism of Osipov and Nemtsov [M. A. Osipov and V. B. Nemtsov, Sov. Phys. Crstallogr. 31, 125 (1986)]. The temperature and order parameter dependence of es and eb are examined, as are separate contributions from different intermolecular interactions. Values of es and eb calculated from simulation are consistent with those found from experiment.© 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

On Cu(110)-p(2×1)-O at 300 K SO[sub 2](g) reacts stoichiometrically with O(a) to form a surface covered with both c(4×2)-SO[sub 3] and p(2×2)-SO[sub 3] structures. With heating SO[sub 2](g) evolves from the surface in distinct reaction-limited states at 384 K, 425 K, and 470 K, and the surface reverts to its initially oxidized state. On Cu(110), SO[sub 2](g) adsorbs molecularly below 300 K; upon annealing to 300 K, the sulfur dioxide disproportionates according to 3SO[sub 2](a)→S(a)+2SO[sub 3](a) with concomitant desorption of excess SO[sub 2](a). The surface formed in this manner exhibits large c(2×2)-S domains which encompass scattered c(4×2)-SO[sub 3] and p(2×2)-SO[sub 3] structures in a 1:2 coverage ratio. After being annealed to 400 K, the surface exhibits large p(2×2)-SO[sub 3] domains surrounding smaller c(4×2)-SO[sub 3] and c(2×2)-S islands. Continued heating past 400 K results in decomposition of sulfite according to SO[sub 3](a)→SO[sub 2](g)+O(a), evolving sulfur dioxide at 470 K and leaving the surface covered with atomic sulfur and oxygen. Real-time STM images show the mobility of oxygen at island boundaries and the mobility of sulfite amid the p(2×1)-O structures. STM measurements suggest that the sulfite occupy four-fold hollow sites. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The article focuses on the launch of the new online system of the journal designed to facilitate all aspects of manuscript submission, peer review and manuscript tracking via Peer X-Press service of the American Institute of Physics (AIP). The service was in collaboration of the journal with AIP to provide effective tools that can assist authors, reviewers and editors in efficiently conducting the peer review process.

The author reflects his experiences as editor of "The Journal of Chemical Physics" in the U.S. He highlights his retirement on the position which will take effect on July 1, 2007 as well as his unforgettable experiences in serving the journal for almost twenty-five years. Furthermore, the author describes his job as wonderful because of the people with whom he associate on a daily basis and has extended his thanks for the support and trust given to him by the management.

© 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We report a new, high-quality x-ray scattering experiment on pure ambient water using a synchrotron beam line at the Advanced Light Source at Lawrence Berkeley National Laboratory. Several factors contribute to the improved quality of our intensity curves including use of a highly monochromatic source, a well-characterized polarization correction, a Compton scattering correction that includes electron correlation, and more accurate intensities using a modern charge coupled device (CCD) detector. We provide a comprehensive description of the data processing that we have used for correcting systematic errors, and we provide an estimate of our remaining random errors. The resulting error estimates of our data are smaller then the discrepancies between data sets collected in past x-ray experiments. We find that the older x-ray curves support a family of g[sub OO](r)'s that exhibit a smaller first peak (∼2.2), while the current data is better fit with a family of g[sub OO](r)'s with a first peak height of 2.8, and systematic shifts in all peak positions to smaller r. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]