JCP: Communications

Communication: Angle-resolved thermal dissociative sticking of CH on Pt(111): Further indication that rotation is a spectator to the gas-surface reaction dynamics

J. K. Navin, S. B. Donald, D. G. Tinney, G. W. Cushing, and I. Harrison
Effusive molecular beam measurements of angle-resolved thermal dissociative sticking coefficients for CH impinging on a Pt(111) surface, at a temperature of 700 K, are reported and compared to theoretical predictions. The reactivity falls off steeply as the molecular angle of incidence increases awa ... [J. Chem. Phys. 136, 061101 (2012)] published Thu Feb 9, 2012.

Communication: Correlation of the instantaneous and the intermediate-time elasticity with the structural relaxation in glassforming systems

F. Puosi and D. Leporini
The elastic models of the glass transition relate the increasing solidity of the glassforming systems with the huge slowing down of the structural relaxation and the viscous flow. The solidity is quantified in terms of the instantaneous shear modulus G, i.e., the immediate response to a step change ... [J. Chem. Phys. 136, 041104 (2012)] published Thu Jan 26, 2012.

Communication: A chemically accurate global potential energy surface for the HO + CO --> H + CO reaction

Jun Li, Yimin Wang, Bin Jiang, Jianyi Ma, Richard Dawes et al.
We report a chemically accurate global potential energy surface for the HOCO system based on high-level ab initio calculations at ~35 000 points. The potential energy surface is shown to reproduce important stationary points and minimum energy paths. Quasi-classical trajectory calculations indicated ... [J. Chem. Phys. 136, 041103 (2012)] published Tue Jan 24, 2012.

Communication: Crystallite nucleation in supercooled glycerol near the glass transition

Hai-Feng Yuan, Ted Xia, Marie Plazanet, Bruno Deme, and Michel Orrit
Heterogeneity and solid-like structures found near the glass transition provide a key to a better understanding of supercooled liquids and of the glass transition. However, the formation of solid-like structures and its effect on spatial heterogeneity in supercooled liquids is neither well documente ... [J. Chem. Phys. 136, 041102 (2012)] published Tue Jan 24, 2012.

Communication: Improving the density functional theory+U description of CeO by including the contribution of the O 2p electrons

Jose J. Plata, Antonio M. Marquez, and Javier Fdez. Sanz
Density functional theory (DFT) based approaches within the local-density approximation or generalized gradient approximation frameworks fail to predict the correct electron localization in strongly correlated systems due to the lack of cancellation of the Coulomb self-interaction. This problem migh ... [J. Chem. Phys. 136, 041101 (2012)] published Mon Jan 23, 2012.

Communication: Quantum mechanics without wavefunctions

Jeremy Schiff and Bill Poirier
We present a self-contained formulation of spin-free non-relativistic quantum mechanics that makes no use of wavefunctions or complex amplitudes of any kind. Quantum states are represented as ensembles of real-valued quantum trajectories, obtained by extremizing an action and satisfying energy conse ... [J. Chem. Phys. 136, 031102 (2012)] published Thu Jan 19, 2012.

Communication: The rotational excitation of D by H: On the importance of the reactive channels

Francois Lique and Alexandre Faure
We report fully-quantum time-independent calculations of cross sections and rate coefficients for the collisional excitation and dissociation of D by H, two astrophysically relevant processes. Our calculations are based on the recent H global potential energy surface of Mielke et al. [J. Chem. Phys. ... [J. Chem. Phys. 136, 031101 (2012)] published Wed Jan 18, 2012.

Communication: High speed optical investigations of a character of boiling-up onset

A. L. Gurashkin, A. A. Starostin, G. V. Ermakov, and P. V. Skripov
In this communication, we discuss the phenomenon of attainable superheat of liquid and the peculiarities of its release by spontaneous boiling-up. We have combined the apparatus for superheating, namely, bubble chamber, with a high speed micro-optical method for detailed monitoring of the initial st ... [J. Chem. Phys. 136, 021102 (2012)] published Fri Jan 13, 2012.

Communication: Beyond Boltzmann's H-theorem: Demonstration of the relaxation theorem for a non-monotonic approach to equilibrium

James C. Reid, Denis J. Evans, and Debra J. Searles
Relaxation of a system to equilibrium is as ubiquitous, essential, and as poorly quantified as any phenomena in physics. For over a century, the most precise description of relaxation has been Boltzmann's H-theorem, predicting that a uniform ideal gas will relax monotonically. Recently, the relaxati ... [J. Chem. Phys. 136, 021101 (2012)] published Wed Jan 11, 2012.

Communication: The reason why +c ZnO surface is less stable than c ZnO surface: First-principles calculation

Seitaro Ito, Tomomi Shimazaki, Momoji Kubo, Hideomi Koinuma, and Masatomo Sumiya
It has been experimentally shown that an O(c)-polar ZnO surface is more stable than a Zn(+c)-polar surface in H ambient. We applied first-principles calculations to investigating the polarity dependence on the stability at the electronic level. The calculations revealed that the c surface terminated ... [J. Chem. Phys. 135, 241103 (2011)] published Thu Dec 29, 2011.

Communication: Spectroscopic phase and lineshapes in high-resolution broadband sum frequency vibrational spectroscopy: Resolving interfacial inhomogeneities of identical molecular groups

Luis Velarde, Xian-yi Zhang, Zhou Lu, Alan G. Joly, Zheming Wang et al.
The ability to achieve sub-wavenumber resolution (0.6 cm) and a large signal-to-noise ratio in high-resolution broadband sum-frequency generation vibrational spectroscopy (HR-BB-SFG-VS) allows for the detailed SFG spectral lineshapes to be used in the unambiguous determination of fine spectral featu ... [J. Chem. Phys. 135, 241102 (2011)] published Thu Dec 29, 2011.

Communication: Manipulating the singlet-triplet equilibrium in organic biradical materials

O. Gunaydın-Şen, J. Fosso-Tande, P. Chen, J. L. White, T. L. Allen et al.
We investigated the tunability of the singlet-triplet equilibrium population in the organic biradical 1,4-phenylenedinitrene via magneto-optical spectroscopy. A rich magnetochromic response occurs because applied field increases the concentration of the triplet state species, which has a unique opti ... [J. Chem. Phys. 135, 241101 (2011)] published Tue Dec 27, 2011.

Communication: Quantum polarized fluctuating charge model: A practical method to include ligand polarizability in biomolecular simulations

S. Roy Kimura, Ramkumar Rajamani, and David R. Langley
We present a simple and practical method to include ligand electronic polarization in molecular dynamics (MD) simulation of biomolecular systems. The method involves periodically spawning quantum mechanical (QM) electrostatic potential (ESP) calculations on an extra set of computer processors using ... [J. Chem. Phys. 135, 231101 (2011)] published Wed Dec 21, 2011.

Communication: Branching ratio measurements in the predissociation of CO by time-slice velocity-map ion imaging in the vacuum ultraviolet region

Hong Gao, Yu Song, Lei Yang, Xiaoyu Shi, Qingzhu Yin et al.
The first direct branching ratio measurement of the three lowest energy dissociation channels of CO that produce C(P) + O(P), C(D) + O(P), and C(P) + O(D) is reported. Rotational resolved carbon ion yield spectra for two Pi bands (W(3ssigma)Pi (v = 3) at 108 012.6 cm and Pi(v = 2) at 109 017 cm) and ... [J. Chem. Phys. 135, 221101 (2011)] published Wed Dec 14, 2011.

Communication: Time-domain measurement of high-pressure N and O self-broadened linewidths using hybrid femtosecond/picosecond coherent anti-Stokes Raman scattering

Joseph D. Miller, Sukesh Roy, James R. Gord, and Terrence R. Meyer
The direct measurement of self-broadened linewidths using the time decay of pure-rotational hybrid femtosecond/picosecond coherent anti-Stokes Raman scattering (fs/ps RCARS) signals is demonstrated in gas-phase N and O from 120 atm. Using fs pump and Stokes pulses and a spectrally narrowed ps probe ... [J. Chem. Phys. 135, 201104 (2011)] published Mon Nov 28, 2011.

Communication: Superatom molecular orbitals: New types of long-lived electronic states

Y. Pavlyukh and J. Berakdar
We present ab initio calculations of the quasiparticle decay times in a Buckminsterfullerene based on the many-body perturbation theory. A particularly lucid representation arises when the broadening of the quasiparticle states is plotted in the angular momentum ([script-l]) and energy ([eh]) coordi ... [J. Chem. Phys. 135, 201103 (2011)] published Mon Nov 28, 2011.

Communication: Partial linearized density matrix dynamics for dissipative, non-adiabatic quantum evolution

Pengfei Huo and David F. Coker
An approach for treating dissipative, non-adiabatic quantum dynamics in general model systems at finite temperature based on linearizing the density matrix evolution in the forward-backward path difference for the environment degrees of freedom is presented. We demonstrate that the approach can capt ... [J. Chem. Phys. 135, 201101 (2011)] published Wed Nov 23, 2011.

Communication: Length scale dependent oil-water energy fluctuations

Robin Underwood and Dor Ben-Amotz
Interfacial fluctuations in the cohesive (van der Waals) interaction energy of spherical oil-drops with water provide evidence of a length scale dependent transition from linear to non-linear response behavior. For sub-nanometer oil-drop sizes, energy fluctuations are found to be independent of the ... [J. Chem. Phys. 135, 201102 (2011)] published Wed Nov 23, 2011.

Communication: A global hybrid generalized gradient approximation to the exchange-correlation functional that satisfies the second-order density-gradient constraint and has broad applicability in chemistry

Roberto Peverati and Donald G. Truhlar
We extend our recent SOGGA11 approximation to the exchange-correlation functional to include a percentage of Hartree-Fock exchange. The new functional, called SOGGA11-X, has better overall performance for a broad chemical database than any previously available global hybrid generalized gradient appr ... [J. Chem. Phys. 135, 191102 (2011)] published Mon Nov 21, 2011.

Communication: Standard surface hopping predicts incorrect scaling for Marcus' golden-rule rate: The decoherence problem cannot be ignored

Brian R. Landry and Joseph E. Subotnik
We evaluate the accuracy of Tully's surface hopping algorithm for the spin-boson model for the case of a small diabatic coupling parameter (V). We calculate the transition rates between diabatic surfaces, and we compare our results to the expected Marcus rates. We show that standard surface hopping ... [J. Chem. Phys. 135, 191101 (2011)] published Mon Nov 21, 2011.

Communication: Limitations of the stochastic quasi-steady-state approximation in open biochemical reaction networks

Philipp Thomas, Arthur V. Straube, and Ramon Grima
It is commonly believed that, whenever timescale separation holds, the predictions of reduced chemical master equations obtained using the stochastic quasi-steady-state approximation are in very good agreement with the predictions of the full master equations. We use the linear noise approximation t ... [J. Chem. Phys. 135, 181103 (2011)] published Mon Nov 14, 2011.