Noise and coupling can optimize the response of arrays of nonlinear elements to periodic signals. We analyze such array-enhanced stochastic resonance (AESR) using finite-state transition rate models. We simply derive the transition rate matrices from the underlying potential energy function of the corresponding Langevin problem. Our implementation exploits Floquet theory and provides useful the...

Structures of the isomeric adamantanediyl dications C(10)H(14)(2+) and protio-1- and protio-2-adamantyl dications C(10)H(16)(2+) were investigated by using the density functional theory (DFT) method at the B3LYP/6-31G** level. Four structures, 1 b-e, were found to be minima on the potential energy surface of C(10)H(14)(2+). The 1,3-adamantanediyl dication 1b with two bridgehead tertiary carboca...

We calculate accurate potential energy curves for HeO(-), NeO(-), and ArO(-), including the full counterpoise correction and allowing for spin-orbit effects. Comparison with previous curves is presented, where these are available. The three curves, (2)Sigma(12) (+), (2)Pi(12), and (2)Pi(32), are used to derive spectroscopic constants and to calculate the transport coefficients for O(-) moving i...

Resonance Raman spectra were acquired for thiophene in cyclohexane solution with 239.5 and 266 nm excitation wavelengths that were in resonance with ∼240 nm first intense absorption band. The spectra indicate that the Franck-Condon region photodissociation dynamics have multidimensional character with motion mostly along the reaction coordinates of six totally symmetry modes and three nontotall...

We demonstrate near linear scaling of a new algorithm for computing smooth local coupled-cluster singles-doubles (LCCSD) correlation energies of quantum mechanical systems. The theory behind our approach has been described previously, [J. Subotnik and M. Head-Gordon, J. Chem. Phys. 123, 064108 (2005)], and requires appropriately multiplying standard iterative amplitude equations by a bump funct...

The minima hopping algorithm (MHOP) to find global minima on potential energy surfaces is used for protein structure prediction. The energy surface of the protein is represented with an all-atom OPLS force field and an implicit free energy solvation term. The system we studied here is the small 10-residue beta-hairpin mini-protein, chignolin. Starting from a completely extended structure, we fo...

Rovibrational states of four dimers formed by the light and the heavy isotopologues of the methane and water molecules are computed using a potential energy surface taken from the literature. The general rovibrational energy-level pattern characteristic to all systems studied is analyzed employing two models of a dimer: the rigidly rotating complex and the coupled system of two rigidly rotating...

A combined theoretical and experimental study was performed on diarylethenes and diarylethene-capped sexithiophenes aiming at an improved understanding of the electrochemical and photochemical ring-opening and ring-closing mechanisms. Theoretical calculations, based on DFT and TDDFT, suggested that the spatial distribution and the occupancy of the frontier orbitals determine and control the dia...

The effect of target location, speed, and handedness on the average total mechanical energy and movement efficiency is studied in 15 healthy subjects (7 males and 8 females with age 22.9 +/- 1.79 years old) performing full body reaching movements. The average total mechanical energy is measured as the time average of integration of joint power, potential energy, and kinetic energy respectively....