JCP: Theoretical Methods and Algorithms http://scitation.aip.org/ JCP: Theoretical Methods and Algorithms First-order phase transitions in repulsive rigid k-mers on two-dimensional lattices http://link.aip.org/link/?JCP/136/064113/1&agg=rss P. M. Pasinetti, F. Roma, and A. J. Ramirez-Pastor<br/> In a previous paper [F. Roma, A. J. Ramirez-Pastor, and J. L. Riccardo, Phys. Rev. B 72, 035444 (2005)], the critical behavior of repulsive rigid rods of length k (k-mers) on a square lattice at half coverage has been studied by using Monte Carlo (MC) simulations. The obtained results indicated that ... [J. Chem. Phys. 136, 064113 (2012)] published Mon Feb 13, 2012. Density functional theory guided Monte Carlo simulations: Application to melting of Na http://link.aip.org/link/?JCP/136/064112/1&agg=rss Satya Bulusu and Rene Fournier<br/> We present a density functional theory (DFT) based Monte Carlo simulation method in which a simple energy function gets fitted on-the-fly to DFT energies and gradients. The fitness of the energy function gets tested periodically using the classical importance function technique [R. Iftimie, D. Salah ... [J. Chem. Phys. 136, 064112 (2012)] published Mon Feb 13, 2012. Vibronic coupling simulations for linear and nonlinear optical processes: Theory http://link.aip.org/link/?JCP/136/064111/1&agg=rss Daniel W. Silverstein and Lasse Jensen<br/> A comprehensive vibronic coupling model based on the time-dependent wavepacket approach is derived to simulate linear optical processes, such as one-photon absorbance and resonance Raman scattering, and nonlinear optical processes, such as two-photon absorbance and resonance hyper-Raman scattering. ... [J. Chem. Phys. 136, 064111 (2012)] published Mon Feb 13, 2012. Vibronic coupling simulations for linear and nonlinear optical processes: Simulation results http://link.aip.org/link/?JCP/136/064110/1&agg=rss Daniel W. Silverstein and Lasse Jensen<br/> A vibronic coupling model based on time-dependent wavepacket approach is applied to simulate linear optical processes, such as one-photon absorbance and resonance Raman scattering, and nonlinear optical processes, such as two-photon absorbance and resonance hyper-Raman scattering, on a series of sma ... [J. Chem. Phys. 136, 064110 (2012)] published Mon Feb 13, 2012. An excited state paired interacting orbital method http://link.aip.org/link/?JCP/136/064109/1&agg=rss Isao Kawata and Hiroya Nitta<br/> A new method for analyzing and visualizing the molecular excited states, named excited state paired interacting orbital (EPIO), is proposed. The method is based both on the paired interacting orbital (PIO) proposed by Fujimoto and Fukui [J. Chem. Phys. 60, 572 (1974)] and the natural transition orbi ... [J. Chem. Phys. 136, 064109 (2012)] published Mon Feb 13, 2012. Markov processes follow from the principle of maximum caliber http://link.aip.org/link/?JCP/136/064108/1&agg=rss Hao Ge, Steve Presse, Kingshuk Ghosh, and Ken A. Dill<br/> Markov models are widely used to describe stochastic dynamics. Here, we show that Markov models follow directly from the dynamical principle of maximum caliber (Max Cal). Max Cal is a method of deriving dynamical models based on maximizing the path entropy subject to dynamical constraints. We give t ... [J. Chem. Phys. 136, 064108 (2012)] published Mon Feb 13, 2012. Calculations of nonlinear response properties using the intermediate state representation and the algebraic-diagrammatic construction polarization propagator approach: Two-photon absorption spectra http://link.aip.org/link/?JCP/136/064107/1&agg=rss S. Knippenberg, D. R. Rehn, M. Wormit, J. H. Starcke, I. L. Rusakova et al.<br/> An earlier proposed approach to molecular response functions based on the intermediate state representation (ISR) of polarization propagator and algebraic-diagrammatic construction (ADC) approximations is for the first time employed for calculations of nonlinear response properties. The two-photon a ... [J. Chem. Phys. 136, 064107 (2012)] published Fri Feb 10, 2012. Critical lines for an unequal size of molecules in a binary gas-liquid mixture around the van Laar point using the combination of the Tompa model and the van der Waals equation http://link.aip.org/link/?JCP/136/064106/1&agg=rss Mustafa Gencaslan and Mustafa Keskin<br/> We combine the modified Tompa model with the van der Waals equation to study critical lines for an unequal size of molecules in a binary gas-liquid mixture around the van Laar point. The van Laar point is coined by Meijer and it is the only point at which the mathematical double point curve is stabl ... [J. Chem. Phys. 136, 064106 (2012)] published Fri Feb 10, 2012. Coherent control and time-dependent density functional theory: Towards creation of wave packets by ultrashort laser pulses http://link.aip.org/link/?JCP/136/064104/1&agg=rss Shampa Raghunathan and Mathias Nest<br/> Explicitly time-dependent density functional theory (TDDFT) is a formally exact theory, which can treat very large systems. However, in practice it is used almost exclusively in the adiabatic approximation and with standard ground state functionals. Therefore, if combined with coherent control theor ... [J. Chem. Phys. 136, 064104 (2012)] published Fri Feb 10, 2012. Transient-time correlation function applied to mixed shear and elongational flows http://link.aip.org/link/?JCP/136/064105/1&agg=rss Remco Hartkamp, Stefano Bernardi, and B. D. Todd<br/> The transient-time correlation function (TTCF) method is used to calculate the nonlinear response of a homogeneous atomic fluid close to equilibrium. The TTCF response of the pressure tensor subjected to a time-independent planar mixed flow of shear and elongation is compared to directly averaged no ... [J. Chem. Phys. 136, 064105 (2012)] published Fri Feb 10, 2012. A neural network potential-energy surface for the water dimer based on environment-dependent atomic energies and charges http://link.aip.org/link/?JCP/136/064103/1&agg=rss Tobias Morawietz, Vikas Sharma, and Jorg Behler<br/> Understanding the unique properties of water still represents a significant challenge for theory and experiment. Computer simulations by molecular dynamics require a reliable description of the atomic interactions, and in recent decades countless water potentials have been reported in the literature ... [J. Chem. Phys. 136, 064103 (2012)] published Thu Feb 9, 2012. Accurate thermochemistry from a parameterized coupled-cluster singles and doubles model and a local pair natural orbital based implementation for applications to larger systems http://link.aip.org/link/?JCP/136/064101/1&agg=rss Lee M. J. Huntington, Andreas Hansen, Frank Neese, and Marcel Nooijen<br/> We have recently introduced a parameterized coupled-cluster singles and doubles model (pCCSD(alpha, beta)) that consists of a bivariate parameterization of the CCSD equations and is inspired by the coupled electron pair approximations. In our previous work, it was demonstrated that the pCCSD(1, 1) m ... [J. Chem. Phys. 136, 064101 (2012)] published Wed Feb 8, 2012. Revised self-consistent continuum solvation in electronic-structure calculations http://link.aip.org/link/?JCP/136/064102/1&agg=rss Oliviero Andreussi, Ismaila Dabo, and Nicola Marzari<br/> The solvation model proposed by Fattebert and Gygi [J. Comput. Chem. 23, 662 (2002)] and Scherlis et al. [J. Chem. Phys. 124, 074103 (2006)] is reformulated, overcoming some of the numerical limitations encountered and extending its range of applicability. We first recast the problem in terms of ind ... [J. Chem. Phys. 136, 064102 (2012)] published Wed Feb 8, 2012. Quadrupole-bound anions: Efficacy of positive versus negative quadrupole moments http://link.aip.org/link/?JCP/136/054116/1&agg=rss W. R. Garrett<br/> A pseudopotential method is utilized to study the critical stability of model anions formed by long-range quadrupolar molecular potentials. Results indicate that critical quadrupole moments of simple point-charge triads do not serve well as predictors of real quadrupole-bound anions of systems with ... [J. Chem. Phys. 136, 054116 (2012)] published Tue Feb 7, 2012. Search for a small hole in a cavity wall by intermittent bulk and surface diffusion http://link.aip.org/link/?JCP/136/054115/1&agg=rss Alexander M. Berezhkovskii and Alexander V. Barzykin<br/> We study the search of a small round hole in the wall of a spherical cavity by a diffusing particle, which can reversibly bind to the cavity wall and diffuse on the surface being in the bound state. There are two channels for the particle first passage to the hole, through the bulk, and through the ... [J. Chem. Phys. 136, 054115 (2012)] published Tue Feb 7, 2012. Exploring the competition between localization and delocalization of the neutral soliton defect in polyenyl chains with the orbital optimized second order opposite spin method http://link.aip.org/link/?JCP/136/054113/1&agg=rss Westin Kurlancheek, Rohini Lochan, Keith Lawler, and Martin Head-Gordon<br/> Theory and implementation of the analytical nuclear gradient is presented for orbital optimized scaled opposite-spin perturbation theory (O2). Evaluation of the O2 analytical gradient scales with the 4th power of molecular size, like the O2 energy. Since the O2 method permits optimization of the orb ... [J. Chem. Phys. 136, 054113 (2012)] published Mon Feb 6, 2012. Stochastic mapping of the Michaelis-Menten mechanism http://link.aip.org/link/?JCP/136/054111/1&agg=rss Eva Doka and Gabor Lente<br/> The Michaelis-Menten mechanism is an extremely important tool for understanding enzyme-catalyzed transformation of substrates into final products. In this work, a computationally viable, full stochastic description of the Michaelis-Menten kinetic scheme is introduced based on a stochastic equivalent ... [J. Chem. Phys. 136, 054111 (2012)] published Mon Feb 6, 2012. Quasi-variational coupled cluster theory http://link.aip.org/link/?JCP/136/054114/1&agg=rss James B. Robinson and Peter J. Knowles<br/> We extend our previous work on the construction of new approximations of the variational coupled cluster method. By combining several linked pair functional transformations in such a way as to give appropriately balanced infinite-order contributions, in order to approximate well at all orders, we f ... [J. Chem. Phys. 136, 054114 (2012)] published Mon Feb 6, 2012. The multi-configuration electron-nuclear dynamics method applied to LiH http://link.aip.org/link/?JCP/136/054112/1&agg=rss Inga S. Ulusoy and Mathias Nest<br/> The multi-configuration electron-nuclear dynamics (MCEND) method is a nonadiabatic quantum dynamics approach to the description of molecular processes. MCEND is a combination of the multi-configuration time-dependent Hartree (MCTDH) method for atoms and its antisymmetrized equivalent MCTDHF for elec ... [J. Chem. Phys. 136, 054112 (2012)] published Mon Feb 6, 2012. The sign problem and population dynamics in the full configuration interaction quantum Monte Carlo method http://link.aip.org/link/?JCP/136/054110/1&agg=rss J. S. Spencer, N. S. Blunt, and W. M.C. Foulkes<br/> The recently proposed full configuration interaction quantum Monte Carlo method allows access to essentially exact ground-state energies of systems of interacting fermions substantially larger than previously tractable without knowledge of the nodal structure of the ground-state wave function. We in ... [J. Chem. Phys. 136, 054110 (2012)] published Mon Feb 6, 2012. Trajectory-guided configuration interaction simulations of multidimensional quantum dynamics http://link.aip.org/link/?JCP/136/054109/1&agg=rss Scott Habershon<br/> We propose an approach to modelling multidimensional quantum systems which uses direct-dynamics trajectories to guide wavefunction propagation. First, trajectory simulations are used to generate a sample of dynamically relevant configurations on the potential energy surface (PES). Second, the sample ... [J. Chem. Phys. 136, 054109 (2012)] published Mon Feb 6, 2012. Nonadiabatic excited-state molecular dynamics: Numerical tests of convergence and parameters http://link.aip.org/link/?JCP/136/054108/1&agg=rss Tammie Nelson, Sebastian Fernandez-Alberti, Vladimir Chernyak, Adrian E. Roitberg, and Sergei Tretiak<br/> Nonadiabatic molecular dynamics simulations, involving multiple Born-Oppenheimer potential energy surfaces, often require a large number of independent trajectories in order to achieve the desired convergence of the results, and simulation relies on different parameters that should be tested and com ... [J. Chem. Phys. 136, 054108 (2012)] published Fri Feb 3, 2012. When does the non-variational nature of second-order Moller-Plesset energies manifest itself? All-electron correlation energies for open-shell atoms from K to Br http://link.aip.org/link/?JCP/136/054107/1&agg=rss Shane P. McCarthy and Ajit J. Thakkar<br/> All-electron correlation energies E are not very well known for open-shell atoms with more than 18 electrons. The complete basis-set (CBS) limits of second-order Moller-Plesset (MP2) perturbation theory energies are obtained for open-shell atoms by computations in large basis sets combined with a kn ... [J. Chem. Phys. 136, 054107 (2012)] published Fri Feb 3, 2012. Effect of dimensionality on the continuum percolation of overlapping hyperspheres and hypercubes http://link.aip.org/link/?JCP/136/054106/1&agg=rss S. Torquato<br/> We show analytically that the [0, 1], [1, 1], and [2, 1] Pade approximants of the mean cluster number S for both overlapping hyperspheres and overlapping oriented hypercubes are upper bounds on this quantity in any Euclidean dimension d. These results lead to lower bounds on the percolation threshol ... [J. Chem. Phys. 136, 054106 (2012)] published Fri Feb 3, 2012. Iterative diagonalization in the state-averaged multi-configurational time-dependent Hartree approach: Excited state tunneling splittings in malonaldehyde http://link.aip.org/link/?JCP/136/054105/1&agg=rss Thorsten Hammer and Uwe Manthe<br/> An iterative block Lanczos-type diagonalization scheme utilizing the state-averaged multi-configurational time-dependent Hartree (MCTDH) approach is introduced. Combining propagation in real and imaginary time and using a set of initial seed wavefunctions corresponding to excitations via the differe ... [J. Chem. Phys. 136, 054105 (2012)] published Fri Feb 3, 2012. Fitting properties from density functional theory based molecular dynamics simulations to parameterize a rigid water force field http://link.aip.org/link/?JCP/136/054103/1&agg=rss Jonas Sala, Elvira Guardia, Jordi Marti, Daniel Spangberg, and Marco Masia<br/> In the quest towards coarse-grained potentials and new water models, we present an extension of the force matching technique to parameterize an all-atom force field for rigid water. The methodology presented here allows to improve the matching procedure by first optimizing the weighting exponents pr ... [J. Chem. Phys. 136, 054103 (2012)] published Thu Feb 2, 2012. Dressed adiabatic and diabatic potentials to study conical intersections for F + H http://link.aip.org/link/?JCP/136/054104/1&agg=rss Anita Das, Tapas Sahoo, Debasis Mukhopadhyay, Satrajit Adhikari, and Michael Baer<br/> We follow a suggestion by Lipoff and Herschbach [Mol. Phys. 108, 1133 (2010)] and compare dressed and bare adiabatic potentials to get insight regarding the low-energy dynamics (e.g., cold reaction) taking place in molecular systems. In this particular case, we are interested to study the effect of ... [J. Chem. Phys. 136, 054104 (2012)] published Thu Feb 2, 2012. Nuclear signatures on the molecular harmonic emission and the attosecond pulse generation http://link.aip.org/link/?JCP/136/054102/1&agg=rss Liqiang Feng and Tianshu Chu<br/> In this paper, we theoretically investigate the nuclear signatures effects, i.e., the initial vibrational state and the isotopic effects on the generations of the molecular high-order harmonics and the attosecond pulses when the model H/D ions are exposed to a 5 fs/800 nm chirp pulse. The numerical ... [J. Chem. Phys. 136, 054102 (2012)] published Thu Feb 2, 2012. Quantum locality and equilibrium properties in low-temperature parahydrogen: A multiscale simulation study http://link.aip.org/link/?JCP/136/054101/1&agg=rss R. Potestio and L. Delle Site<br/> Parahydrogen is the spin-zero singlet state of molecular hydrogen, which at low temperature (between 14 and 25 K) is in a fluid state. A classical treatment of the system leads to unphysical freezing, and the inclusion of quantum delocalization of the molecule is then required to obtain a realistic ... [J. Chem. Phys. 136, 054101 (2012)] published Wed Feb 1, 2012. Parallel density matrix propagation in spin dynamics simulations http://link.aip.org/link/?JCP/136/044108/1&agg=rss Luke J. Edwards and Ilya Kuprov<br/> Several methods for density matrix propagation in parallel computing environments are proposed and evaluated. It is demonstrated that the large communication overhead associated with each propagation step (two-sided multiplication of the density matrix by an exponential propagator and its conjugate) ... [J. Chem. Phys. 136, 044108 (2012)] published Tue Jan 31, 2012. Robust interpolation between weak- and strong-correlation regimes of quantum systems http://link.aip.org/link/?JCP/136/044109/1&agg=rss Jerzy Cioslowski<br/> A robust interpolation between the weak- and strong-correlation regimes of quantum systems is presented. It affords approximants to the function E(omega) describing the dependence of the total energy (or other observable) on the coupling parameter omega that measures the correlation strength. The ap ... [J. Chem. Phys. 136, 044109 (2012)] published Tue Jan 31, 2012.