@article {2649,
	title = {Free Energy Barrier Estimation for the Dissociation of Charged Protein Complexes in the Gas Phase},
	journal = {Journal of Physical Chemistry A},
	volume = {113},
	number = {16},
	year = {2009},
	note = {ISI Document Delivery No.: 435ZUTimes Cited: 4Cited Reference Count: 29Wanasundara, Surajith N. Thachuk, Mark},
	month = {Apr},
	pages = {3814-3821},
	type = {Article},
	abstract = {Free energies are calculated for the protonated cytochrome c{\textquoteright} dimer ion in the gas phase as a function of the center of mass distance between the monomers. A number of different charge partitionings are examined as well as the behavior of the neutral complex. It is found that monomer unfolding competes with complex dissociation and that the relative importance of these two factors depends upon the charge partitioning in the complex. Symmetric charge partitionings preferentially suppress the dissociation barrier relative to unfolding, and complexes tend to dissociate promptly with little structural changes occurring in the monomers. Alternatively, asymmetric charge partitionings preferentially lower the barrier for monomer unfolding relative to the dissociation barrier. In this case, the monomer with the higher charge unfolds before the complex dissociates. For the homodimer considered here, this pathway has a large free energy barrier. The results can be rationalized using schematic two-dimensional free energy surfaces. Additionally, for large multimeric complexes, it is argued that the unfolding and subsequent charging of a single monomer is a favorable process, cooperatively lowering both the unfolding and dissociation barriers at the same time.},
	keywords = {ASSEMBLIES, ELECTROSPRAY-IONIZATION, MASS-SPECTROMETRY, MODEL, MOLECULAR-DYNAMICS, ORIGIN, PATHWAYS, SIMULATIONS, SYSTEMS, THERMAL-DISSOCIATION},
	isbn = {1089-5639},
	url = {<Go to ISI>://000265383200014},
	author = {Wanasundara, S. N. and Thachuk, M.}
}
@article {2620,
	title = {Structural and dynamical properties of ionic liquids: The influence of charge location},
	journal = {Journal of Chemical Physics},
	volume = {130},
	number = {10},
	year = {2009},
	note = {ISI Document Delivery No.: 420IFTimes Cited: 8Cited Reference Count: 31Spohr, H. V. Patey, G. N.},
	month = {Mar},
	pages = {11},
	type = {Article},
	abstract = {The properties of ionic liquids depend on the chemical structure of the constituent ions. An important difference between molten inorganic salts and room temperature ionic liquids (RTILs) is that in RTILs the charge is frequently not located at the center of mass. This paper describes a molecular dynamics investigation of the influence of charge location on the structure and transport properties of ionic liquids. The model considered consists of univalent spherical ions with the cation charge moved away from its center of mass. It is shown that the charge location has an important influence on the liquid properties. As the charge is moved off center, the electrical conductivity initially increases, and the shear viscosity decreases. However, when the charge exceeds a certain displacement, this behavior is reversed. With further charge displacement, the conductivity decreases sharply and the viscosity increases rapidly. This behavior reversal can be traced to the formation of directional ion pairs that are present in sufficient numbers, and have lifetimes sufficiently long to strongly influence the liquid properties. We suggest that the influence of directional ion pairing can explain what appear to be anomalously low conductivities and high viscosities observed for some RTILs. The rotational and reorientational motions of the cations are examined, and shown to be strongly influenced by ion-pair formation when the charge is far off center. The temperature dependence of the transport properties is considered for selected systems, and deviations from Arrhenius behavior are found to be most important for the conductivity. Based on our results, this possibly indicates that directional ion pairs create an additional "barrier" to charge transport in some ionic liquids.},
	keywords = {ANION, DIFFUSION, electrical conductivity, HYDROGEN-BONDS, liquid metals, liquid structure, liquid theory, molecular dynamics method, MOLECULAR-DYNAMICS, PHYSICOCHEMICAL PROPERTIES, pressure, TEMPERATURE, TRANSPORT-PROPERTIES, VISCOSITIES, VISCOSITY},
	isbn = {0021-9606},
	url = {<Go to ISI>://000264281800024},
	author = {Spohr, H. V. and Patey, G. N.}
}
@article {2218,
	title = {Hydrophobic interactions in urea - Trimethylamine-N-oxide solutions},
	journal = {Journal of Physical Chemistry B},
	volume = {112},
	number = {35},
	year = {2008},
	note = {ISI Document Delivery No.: 342RDTimes Cited: 2Cited Reference Count: 25Paul, Sandip Patey, G. N.},
	month = {Sep},
	pages = {11106-11111},
	type = {Article},
	abstract = {The influence of osmolytes urea and trimethylemine-N-oxide (TMAO) on hydrophobic interactions is investigated employing molecular dynamics simulations. These osmolytes are of interest because of their opposing influence on proteins in solution; the denaturing effect of urea can be countered with TMAO. A neopentane pair is used to model typical nonpolar entities. Binary water-urea and water-TMAO as well as ternary water-urea-TMAO systems are considered. Neopentane-neopentane potentials of mean force, neopentane-water, and neopentane-osmolyte distribution functions are reported. Urea is found to have only modest influence on the neopentane-neopentane potential of mean force, but the hydrophobic attraction is completely destroyed by the presence of TMAO. It is shown that TMAO tends to act as a simple "surfactant" displacing water and urea (if it is present) from the first solvation shell of neopentane. It is likely the surfactant-like influence of TMAO that accounts for the elimination of the hydrophobic attraction. The implications of Our results for explanations of the action of TMAO in protein solutions are discussed.},
	keywords = {AQUEOUS UREA, FORCE, MOLECULAR-DYNAMICS, OSMOLYTES, POTENTIALS, PROTEIN DENATURATION, SIMULATIONS, WATER},
	isbn = {1520-6106},
	url = {<Go to ISI>://000258800300046},
	author = {Paul, S. and Patey, G. N.}
}
@article {2258,
	title = {Structural and dynamical properties of ionic liquids: The influence of ion size disparity},
	journal = {Journal of Chemical Physics},
	volume = {129},
	number = {6},
	year = {2008},
	note = {ISI Document Delivery No.: 338FDTimes Cited: 10Cited Reference Count: 28Spohr, H. V. Patey, G. N.},
	month = {Aug},
	pages = {8},
	type = {Article},
	abstract = {The influence of ion size disparity on structural and dynamical properties of ionic liquids is systematically investigated employing molecular dynamics simulations. Ion size ratios are varied over a realistic range (from 1:1 to 5:1) while holding other important molecular and system parameters fixed. In this way we isolate and identify effects that stem from size disparity alone. In strongly size disparate systems the larger species (cations in our model) tend to dominate the structure; the anion-anion distribution is largely determined by anion-cation correlations. The diffusion coefficients of both species increase, and the shear viscosity decreases with increasing size disparity. The influence of size disparity is strongest up to a size ratio of 3:1, then decreases, and by 5:1 both the diffusion coefficients and viscosity appear to be approaching limiting values. The conventional Stokes-Einstein expression for diffusion coefficients holds reasonably well for the cations but fails for the smaller anions as size disparity increases likely due to the neglect of strong anion-cation correlations. The electrical conductivity is not a simple monotonic function of size disparity; it first increases up to size ratios of 2:1, remains nearly constant until 3:1, then decreases such that the conductivities of the 1:1 and 5:1 systems are similar. This behavior is traced to the competing influences of ion diffusion (enhancing) and ion densities (reducing) on conductivities at constant packing fraction. The temperature dependence of the transport properties is examined for the 1:1 and 3:1 systems. In accord with experiment, the temperature dependence of all transport properties is well represented by the Vogel-Fulcher-Tammann equation. The dependence of the diffusion coefficients on the temperature/viscosity ratio is well described by the fractional Stokes-Einstein relation D proportional to(T/eta)(beta) with beta approximate to 0.8, consistent with the exponent observed for many molten inorganic salts.},
	keywords = {MOLECULAR-DYNAMICS, PHYSICOCHEMICAL PROPERTIES, pressure, SIMULATION, TRANSPORT-PROPERTIES},
	isbn = {0021-9606},
	url = {<Go to ISI>://000258490600052},
	author = {Spohr, H. V. and Patey, G. N.}
}
@article {1356,
	title = {Collision-induced alignment of H2O+ drifting in helium},
	journal = {Journal of Chemical Physics},
	volume = {124},
	number = {17},
	year = {2006},
	note = {ISI Document Delivery No.: 039QQTimes Cited: 0Cited Reference Count: 27},
	month = {May},
	pages = {8},
	type = {Article},
	abstract = {The collision-induced alignment of H2O+ drifting in helium is studied with a molecular dynamics method that has been extended to treat nonlinear rigid ions. Rotational distribution functions and averaged quantities are presented in terms of the rho formalism [M. Thachuk, Phys. Rev. A 72, 032722 (2005)], and it is shown that this description gives a very good agreement with simulation results. In addition to velocity and angular velocity autocorrelation functions, a velocity-angular velocity cross correlation function is introduced. This cross correlation function provides insight into the dynamical nature of the alignment mechanism. 2006 American Institute of Physics.},
	keywords = {CROSS-SECTIONS, CYTOCHROME-C, ELECTROSTATIC FIELDS, IN-VACUO, INTRINSIC SIZE PARAMETERS, ION-MOTION, MOLECULAR-DYNAMICS, MONTE-CARLO-SIMULATION, POTENTIAL-ENERGY SURFACES, ROTATIONAL ALIGNMENT},
	isbn = {0021-9606},
	url = {<Go to ISI>://000237321700019},
	author = {Chen, X. and Thachuk, M.}
}
@article {1521,
	title = {Why tert-butyl alcohol associates in aqueous solution but trimethylamine-N-oxide does not},
	journal = {Journal of Physical Chemistry B},
	volume = {110},
	number = {21},
	year = {2006},
	note = {ISI Document Delivery No.: 046XRTimes Cited: 14Cited Reference Count: 41},
	month = {Jun},
	pages = {10514-10518},
	type = {Article},
	abstract = {In dilute aqueous solution, tert-butyl alcohol (TBA) tends to aggregate but trimethylamine-N-oxide ( TMAO) does not. Given that both molecules have very similar geometry with hydrophobic and hydrophilic groups, it is interesting to ask why they behave so differently in aqueous solution. To explore this question, we use molecular dynamics simulations to study two models representing TBA and TMAO that differ essentially only in their electrostatic properties. It is shown that this difference is sufficient to give the different solution behavior. Furthermore, the principal difference identified is that the hydrophilic group of TMAO ( the oxygen) interacts on average much more strongly with water than the corresponding group ( the hydroxyl) of TBA. A hydrogen-bond analysis shows that water-TBA and water-TMAO hydrogen bonds are similar in number, but that the hydrogen-bond energy is much more negative for water-TMAO. In all likelihood, this accounts for the different behavior in dilute aqueous solution.},
	keywords = {BINARY-MIXTURES, CLATHRATE HYDRATE FORMATION, ELECTROLYTE SOLUTIONS, HYDROGEN-BOND DYNAMICS, HYDROPHOBIC INTERACTIONS, LIGHT-SCATTERING, LIQUID, MOLECULAR-DYNAMICS, SIMULATION, WATER MIXTURES},
	isbn = {1520-6106},
	url = {<Go to ISI>://000237844900046},
	author = {Paul, S. and Patey, G. N.}
}
@article {1231,
	title = {On the evaluation of the Kirkwood-Buff integrals of aqueous acetone mixtures},
	journal = {Journal of Chemical Physics},
	volume = {123},
	number = {2},
	year = {2005},
	note = {ISI Document Delivery No.: 947NUTimes Cited: 14Cited Reference Count: 46},
	month = {Jul},
	pages = {11},
	type = {Article},
	abstract = {The Kirkwood-Buff integrals of acetone-water mixtures are determined using two experimental techniques: small-angle neutron scattering and vapor pressure measurements, in order to test the precision and reliability that can be achieved. The data are then compared with those previously reported by different authors, which tend to show considerable variation between them. The various possible sources of inaccuracies are pointed out, both from experimental origins and from the numerical treatment of the data. Comparison with recent simulation results allows to critically compare different models and provide some information about the microstructure of the aqueous mixture. (c) 2005 American Institute of Physics.},
	keywords = {CONCENTRATION, FLUCTUATION, HENRYS LAW REGION, MOLECULAR-DYNAMICS, NEUTRON-SCATTERING, ORGANIC SOLUTES, TERT-BUTYL ALCOHOL, TETRAMETHYL UREA, TOTAL PRESSURE, WATER MIXTURES, X-RAY-SCATTERING},
	isbn = {0021-9606},
	url = {<Go to ISI>://000230653700023},
	author = {Perera, A. and Sokolic, F. and Almasy, L. and Westh, P. and Koga,Yoshikata}
}
@article {1076,
	title = {Ground and first-excited global potential energy surfaces of the H2O+-He complex: Predictions of ion mobilities},
	journal = {International Journal of Quantum Chemistry},
	volume = {101},
	number = {1},
	year = {2005},
	note = {ISI Document Delivery No.: 872KKTimes Cited: 2Cited Reference Count: 29},
	month = {Jan},
	pages = {1-7},
	type = {Article},
	abstract = {Ion mobilities of H2O+ drifting in helium are calculated and compared with experiment. These calculations employ global potential energy surfaces of the H2O+-He complex, which in the present case were calculated ab initio at the unrestricted MP2 level of theory using a basis set of aug-cc-pVTZ quality, and treating the ion as a rigid body. Details are presented of the general characteristics of both the ground and first-excited electronic states of the complex. Although only the ground-state surface was used for the mobility calculations, the ab initio determination of the ground state necessitated the inclusion of the first-excited state owing to the presence of a crossing between the two. This crossing is also described. Mobilities calculated from the global surfaces are in good agreement with experiment. (C) 2004 Wiley Periodicals, Inc.},
	keywords = {AB-INITIO, COLLISIONAL ALIGNMENT, first-excited state, global energy, H2O+-He complex, HELIUM, INDUCED ROTATIONAL ALIGNMENT, ion mobility, MICROSOLVATION, MOLECULAR-DYNAMICS, MP2, SPECTRA, SUPERSONIC EXPANSIONS, SURFACE, VELOCITY, WATER CATION},
	isbn = {0020-7608},
	url = {<Go to ISI>://000225205900001},
	author = {Chen, X. and Thachuk, M.}
}
@article {1283,
	title = {Nonequilibrium distribution functions for general rigid bodies in axially symmetric environments},
	journal = {Physical Review A},
	volume = {72},
	number = {3},
	year = {2005},
	note = {ISI Document Delivery No.: 969IRTimes Cited: 0Cited Reference Count: 20},
	month = {Sep},
	pages = {10},
	type = {Article},
	abstract = {A vector rho is introduced in such a manner that the equilibrium rotational distribution function for a general rigid body has a simple quadratic form both from a body-fixed and space-fixed frame of reference. It is shown that when considering nonequilibrium distribution functions, representations employing the components of rho generalize more easily than those employing the components of the angular momentum or angular velocity, and lead to forms with greater accuracy. The behavior of rho and its relation to the angular momentum of the system is explored in some detail. Comparisons are made with distribution functions generated from molecular dynamics simulations of H2O+ drifting in a helium bath gas under the influence of a uniform electric field.},
	keywords = {ALIGNMENT, COLLISION CROSS-SECTIONS, HELIUM, IONS, MOBILITIES, MOLECULAR-DYNAMICS, POTENTIAL-ENERGY SURFACES, ROTATIONAL, SCATTERING, SUPERSONIC EXPANSIONS, VELOCITY},
	isbn = {1050-2947},
	url = {<Go to ISI>://000232228300102},
	author = {Thachuk, M.}
}
@article {346,
	title = {Collision-induced alignment of NO+ drifting in argon: Calculated distribution functions and microscopic quadrupole alignment parameters},
	journal = {Journal of Chemical Physics},
	volume = {116},
	number = {15},
	year = {2002},
	note = {ISI Document Delivery No.: 537PGTimes Cited: 5Cited Reference Count: 32},
	month = {Apr},
	pages = {6605-6613},
	type = {Article},
	abstract = {Molecular dynamics simulations of NO+ drifting in argon are presented. In this system, the ion-bath gas mass ratio is close to but less than unity, thus increasing the importance of inelastic collisions. Strong velocity-angular momentum coupling is found, and in particular the quadrupolar alignment parameter as a function of the velocity parallel with the field takes on, with decreasing velocities, values that start as negative, become positive, and subsequently decay toward negative. To the best of our knowledge, this is the first report of the decay of this alignment towards negative values at the low end of the velocity distribution. The accuracy of an approximate distribution function [R. Baranowski and M. Thachuk, Phys. Rev. A 63, 032503 (2001)] is also examined in detail. It is found to give results that are generally qualitatively correct, and for many properties, semiquantitatively correct as well. The agreement, however, is not as good as that found for systems with ion-bath gas ratios greatly exceeding unity. (C) 2002 American Institute of Physics.},
	keywords = {AR-NO+, ATOMIC GASES, EXPANSIONS, ION MOBILITY SPECTROMETRY, MOLECULAR-DYNAMICS, ROTATIONAL ALIGNMENT, SCATTERING, SUPERSONIC, SURFACES, TRANSPORT, VELOCITY DISTRIBUTIONS},
	isbn = {0021-9606},
	url = {<Go to ISI>://000174767200023},
	author = {Chen, X. and Araghi, R. and Baranowski, R. and Thachuk, M.}
}
@article {375,
	title = {Hyperfine and host-guest interactions of the Mu-cyclohexadienyl radical in NaY zeolite},
	journal = {Journal of Physical Chemistry B},
	volume = {106},
	number = {25},
	year = {2002},
	note = {ISI Document Delivery No.: 565EUTimes Cited: 8Cited Reference Count: 88},
	month = {Jun},
	pages = {6395-6407},
	type = {Article},
	abstract = {The adsorption and dynamical behavior of the muonated cyclohexadienyl radical (C(6)H(6)Mu) in NaY zeolite, formed by muonium (Mu) addition on adsorbed benzene. was investigated by the muon spin resonance (muSR) technique, primarily at loadings of 2-3 C6H6 molecules per supercage of NaY. The dynamics of this radical are expected to be the same as its isotopic analogue, C6H7, for which there are no similar data available. Both TF-muSR and ALC-muSR spectra were recorded, with the most detailed information provided by the positions and line widths of the avoided level crossing resonances. In concert with H-2 NMR, neutron diffraction and molecular dynamics studies of the parent benzene molecule, as well as current theoretical calculations, the dominant adsorption site for the C(6)H(6)Mu radical is believed to be the S-II Na cation, within a supercage, which gives rise to three observed ALC lines, corresponding to two different orientations for the muon (proton) of the CHMu methylene group: pointing toward (endo) and away (exo) from the Na cation. The cation interaction gives rise to unprecedentedly large (approximate to20\%) shifts in hyperfine coupling constants, indicative of a strong bond formed with the T electrons of the C(6)H(6)Mu radical. An additional but weaker resonance line is also seen, which is interpreted as being due to adsorption at the window sites between supercages. The ALC lines associated with the CH,,Mu radical bound to both the Na cation and window sites are all broad, approximate to1 kG, change little with temperature and exhibit mainly static line shapes over the whole temperature range studied, from 3 to 322 K. This indicates a much stronger host-guest interaction for C(6)H(6)Mu, particularly with the Na cation. than is known for benzene, to the extent that this site acts as an effective trap for the free radical, over the critical muSR time scale of 50 ns.},
	keywords = {AROMATIC-MOLECULES, ELASTIC NEUTRON-SCATTERING, GAS-PHASE, H-2 NMR, MAGNETIC-RESONANCE, MOLECULAR-DYNAMICS, RAY-POWDER DIFFRACTION, REORIENTATIONAL DYNAMICS, SODIUM-Y ZEOLITE, SPIN RELAXATION},
	isbn = {1520-6106},
	url = {<Go to ISI>://000176356700007},
	author = {Fleming, Donald G. and Shelley, M. Y. and Arseneau, D. J. and Senba, M. and Pan, J. J. and Roduner, E.}
}
@article {4895,
	title = {Forces between like-charged walls in an electrolyte solution: A comparison of McMillan-Mayer results for several models},
	journal = {Journal of Chemical Physics},
	volume = {113},
	number = {7},
	year = {2000},
	note = {ISI Document Delivery No.: 344XYTimes Cited: 8Cited Reference Count: 28},
	month = {Aug},
	pages = {2851-2855},
	type = {Article},
	abstract = {The interaction of like-charged walls immersed in aqueous solutions with monovalent counterions is investigated at the McMillan-Mayer (MM) level of description. The net pressure acting between the walls is obtained by applying the anisotropic hypernetted-chain theory. The MM approach requires solvent-averaged ion-ion potentials of mean force as input. Results based on "realistic" models for Na+ and Cl- in water are available in the literature and these are used in the present calculations. The wall-wall interactions obtained can differ dramatically from the primitive model (dielectric continuum solvent) case. For some models attractive wall-wall forces are observed at small separations. The MM theory is found to be rather sensitive to details of the counterion-counterion potential of mean force, and different models for the same counterion can give qualitatively different results. At present it is difficult to evaluate the relative accuracy of the different models that have been proposed. However, the results presented here give at least an idea of the interesting possibilities that lie in the physically realistic range. (C) 2000 American Institute of Physics. [S0021-9606(00)50331-6].},
	keywords = {APPROXIMATION, DOUBLE-LAYER, FORCE, HARD-SPHERES, IMAGE INTERACTIONS, INHOMOGENEOUS COULOMB FLUIDS, MEAN, MOLECULAR-DYNAMICS, PLANAR SURFACES, SODIUM-CHLORIDE, WATER},
	isbn = {0021-9606},
	url = {<Go to ISI>://000088787400034},
	author = {Otto, F. and Patey, G. N.}
}
@article {4516,
	title = {Ion solvation dynamics in water-methanol and water-dimethylsulfoxide mixtures},
	journal = {Journal of Chemical Physics},
	volume = {110},
	number = {22},
	year = {1999},
	note = {ISI Document Delivery No.: 199FFTimes Cited: 50Cited Reference Count: 31},
	month = {Jun},
	pages = {10937-10944},
	type = {Article},
	abstract = {The dynamics of selective ion solvation in water-methanol and water-dimethylsulfoxide (DMSO) systems is investigated using molecular dynamics simulations. The results are compared with earlier work involving simple dipolar models. Solvation response functions, S(t), are used to follow the energetic relaxation, and particle solvation response functions, P(t), introduced in our earlier work, are used to examine the compositional relaxation of the first solvation shell. Despite the presence of hydrogen bonding, the dynamical behavior in water-methanol systems was found to be very similar to that observed for simple Stockmayer solvents. For the water-DMSO mixtures, it was found that the relative sizes and geometries of the solvent species can have a substantial influence on the preferential solvation process. For positively charged solutes in water-DMSO the physical picture does not differ greatly from the water-methanol case. However, for negative solutes the DMSO component shows only a weak response to the charge, and the solvation process consists largely of water molecules moving slowly to the solute through an essentially static DMSO medium. Our results also illustrate that the usual solvation response function, which depends on the total solute-solvent energy, is not a very sensitive probe of selective solvation dynamics. The contribution to the total solute-solvent energy from preferential solvation is very small compared to the contributions from the relatively rapid solvent reorientation and electrostriction processes. The dynamics of selective solvation is evident in species-specific functions but these are not obtained experimentally. The insensitivity of the usual solvation response function has been noticed in recent experimental studies, and an alternative function that appears to be more sensitive to the solvent composition near the solute has been suggested. (C) 1999 American Institute of Physics. [S0021-9606(99)50621-1].},
	keywords = {DIPOLAR LIQUIDS, ELECTRON-TRANSFER, MOLECULAR-DYNAMICS, PICOSECOND, POLAR, SIMULATION, SOLVENT DYNAMICS, TIME-RESOLVED FLUORESCENCE},
	isbn = {0021-9606},
	url = {<Go to ISI>://000080469200035},
	author = {Day, T. J. F. and Patey, G. N.}
}
@article {4417,
	title = {A semiclassical approach to intense-field above-threshold dissociation in the long wavelength limit. II. Conservation principles and coherence in surface hopping},
	journal = {Journal of Chemical Physics},
	volume = {109},
	number = {14},
	year = {1998},
	note = {ISI Document Delivery No.: 125BETimes Cited: 28Cited Reference Count: 24},
	month = {Oct},
	pages = {5747-5760},
	type = {Article},
	abstract = {This paper is a companion to our recently published semiclassical formalism for treating time-dependent Hamiltonians [J. Chem. Phys, 105, 4094 (1996)], which was applied to study the dissociation of diatomic ions in intense laser fields. Here two fundamental issues concerning this formalism are discussed in depth: conservation principles and coherence. For time-dependent Hamiltonians, the conservation principle to apply during a trajectory hop depends upon the physical origin of the electronic transition, with total energy conservation and nuclear momentum conservation representing the two limiting cases. It is shown that a]applying an inappropriate scheme leads to unphysical features in the kinetic energy of the dissociation products. A method is introduced that smoothly bridges the two limiting cases and applies the physically justified conservation scheme at all times. It is also shown that the semiclassical formalism can predict erroneous results if the electronic amplitudes for well-separated hops are added coherently. This is a fundamental problem with the formalism which leads to unphysical results if left unattended. Alternative schemes are introduced for dealing with this problem and their accuracies are assessed. Generalization of the well-known Landau-Zener formula to the time-dependent Hamiltonian case is derived, which allows one to significantly decrease the computational overhead involved with the numerical implementation of the semiclassical method. Finally, we show that in strong-field molecular dissociation a trajectory can {\textquoteright}{\textquoteright}surf" a moving avoided crossing. In this case the hopping probability is a sensitive function of the interference between two closely spaced avoided crossing regions. (C) 1998 American Institute of Physics.},
	keywords = {COULOMB EXPLOSION, DIATOMIC-MOLECULES, ENHANCED, H-2(+), IONIZATION, LASER FIELDS, MODEL, MOLECULAR-DYNAMICS, PHOTODISSOCIATION, QUANTUM DECOHERENCE, TRANSITIONS},
	isbn = {0021-9606},
	url = {<Go to ISI>://000076216900008},
	author = {Thachuk, M. and Ivanov, M. Y. and Wardlaw, D. M.}
}
@article {3723,
	title = {Normalized fluctuations, H2O vs n-hexane: Site-correlated percolation},
	journal = {Journal of Chemical Physics},
	volume = {105},
	number = {5},
	year = {1996},
	note = {ISI Document Delivery No.: UZ525Times Cited: 20Cited Reference Count: 49},
	month = {Aug},
	pages = {2028-2033},
	type = {Article},
	abstract = {Entropy, volume and the cross fluctuations were normalized to the average volume of a coarse grain with a fixed number of molecules, within which the local and instantaneous value of interest is evaluated. Comparisons were made between liquid H2O and n-hexane in the range from -10 degrees C to 120 degrees C and from 0.1 MPa to 500 MPa. The difference between H2O and n-hexane in temperature and pressure dependencies of these normalized fluctuations was explained in terms of the site-correlated percolation theory for H2O. In particular, the temperature increase was confirmed to reduce the hydrogen bond probability, while the pressure appeared to have little effect on the hydrogen bond probability. According to the Le Chatelier principle, however, the putative formation of {\textquoteright}{\textquoteright}ice-like{\textquoteright}{\textquoteright} patches at low temperatures due to the site-correlated percolation requirement is retarded by pressure increases. Thus, only in the limited region of low pressure (<300 MPa) and temperature (<60 degrees C), the fluctuating ice-like patches are considered to persist. (C) 1996 American Institute of Physics.},
	keywords = {2 KINDS, AQUEOUS 2-BUTOXYETHANOL, density, H-BONDS, HEAVY-WATER, LIQUID WATER, mixing, MOLECULAR-DYNAMICS, pressure, SCHEME, TEMPERATURES},
	isbn = {0021-9606},
	url = {<Go to ISI>://A1996UZ52500029},
	author = {Koga,Yoshikata and Westh, P. and Sawamura, S. and Taniguchi, Y.}
}
@article {3487,
	title = {CONFORMATIONAL EQUILIBRIUM AND ORIENTATIONAL ORDERING - H-1-NUCLEAR MAGNETIC-RESONANCE OF BUTANE IN A NEMATIC LIQUID-CRYSTAL},
	journal = {Journal of Chemical Physics},
	volume = {103},
	number = {16},
	year = {1995},
	note = {ISI Document Delivery No.: TA441Times Cited: 25Cited Reference Count: 60},
	month = {Oct},
	pages = {6891-6902},
	type = {Article},
	abstract = {In this study we use multiple-quantum H-1-NMR spectroscopy to study butane, the simplest flexible alkane, dissolved in a nematic solvent. An analysis of the highly accurate H-1 dipolar coupling constants gives important information about conformational and orientational behavior, including the hans-gauche energy difference, E(tg), and the conformer probabilities and order parameters. An essential component of the analysis involves the use of mean-field models to describe the orientational ordering of solutes in a nematic solvent. Several models were found to adequately describe the molecular ordering, including the chord model of Photinos et al. [D. J. Photinos, E. T. Samulski, and H. Toriumi, J. Phys. Chem. 94, 4688 (1990)] and recent versions of a model proposed by Burnell and co-workers [D. S. Zimmerman and E. E. Burnell, Mel. Phys. 78, 687 (1993)]. It was found that E(tg) lies in the range 2.1-3.0 kJ/mol, which is significantly below most experimental estimates of the gas-phase value. An attempt to describe more realistically the conformational states by including torsional fluctuations about the rotational isomeric states did not significantly improve the quality of the fits or alter the results. Finally the anisotropic component of the solute-solvent interaction was found to perturb only marginally the conformational probabilities from the isotropic values. (C) 1995 American Institute of Physics.},
	keywords = {ALKYL CHAINS, ANISOTROPIC LIQUIDS, ELECTRON-DIFFRACTION, INTERNAL-ROTATION, MOLECULAR-DYNAMICS, N-BUTANE, NORMAL-HEXANE, POTENTIAL FUNCTION, PROTON DIPOLAR COUPLINGS, STATISTICAL-MECHANICS},
	isbn = {0021-9606},
	url = {<Go to ISI>://A1995TA44100007},
	author = {Polson, J. M. and Burnell, E. E.}
}
@inbook {3163,
	title = {MUON SPIN RELAXATION STUDIES OF CYCLOHEXADIENYL RADICALS IN NAUSY},
	booktitle = {Zeolites and Related Microporous Materials: State of the Art 1994},
	series = {Studies in Surface Science and Catalysis},
	volume = {84},
	year = {1994},
	note = {ISI Document Delivery No.: BD02ETimes Cited: 3Cited Reference Count: 22Proceedings Paper10th International Zeolite ConferenceJUL 17-22, 1994GARMISCH PARTENKIR, GERMANYSARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS},
	pages = {469-475},
	publisher = {Elsevier Science Publ B V},
	organization = {Elsevier Science Publ B V},
	address = {Amsterdam},
	abstract = {The avoided level crossing muon spin resonance (ALC-mu SR) technique is a promising new tool that can be used as a highly sensitive microscopic probe of radical motions in zeolites. We report a recent experiment in which this technique was used to identify a muonated cyclohexadienyl radical (C(6)H(6)Mu) and explore its reorientational dynamics in NaUSY. The observed evolution of the Delta M=1 ALC resonance lines are interpreted in terms of the site exchange dynamics of the radical.},
	keywords = {benzene, DIFFUSION, LEVEL-CROSSING RESONANCE, LOCALIZATION, MOLECULAR-DYNAMICS, NAX, NMR, NUCLEAR MAGNETIC-RESONANCE, SODIUM-Y ZEOLITE},
	isbn = {0-444-81847-2},
	url = {<Go to ISI>://A1994BD02E00057},
	author = {Shelley, M. and Arseneau, D. J. and Senba, M. and Pan, J. J. and Snooks, R. and Kreitzman, S. R. and Fleming, Donald G. and Roduner, E.},
	editor = {Weitkamp, J. and Karge, H. G. and Pfeifer, H. and Holderich, W.}
}
@article {2993,
	title = {STRUCTURE OF 2-COMPONENT CLUSTERS},
	journal = {Journal of Chemical Physics},
	volume = {101},
	number = {3},
	year = {1994},
	note = {ISI Document Delivery No.: NY002Times Cited: 43Cited Reference Count: 17},
	month = {Aug},
	pages = {2432-2445},
	type = {Article},
	abstract = {{Phase separation in binary liquid Lennard-Jones clusters is investigated employing computer simulation methods. Clusters ranging in size from 50 to 240 particles are considered with special emphasis on systems with equal numbers of A and B particles. Cluster morphology is systematically explored by varying the ratios},
	keywords = {MOLECULAR-DYNAMICS, SIMULATIONS, TRANSITION},
	isbn = {0021-9606},
	url = {<Go to ISI>://A1994NY00200071},
	author = {Clarke, A. S. and Kapral, R. and Patey, G. N.}
}
@article {2929,
	title = {DYNAMIC PROPERTIES OF A FERROELECTRIC NEMATIC LIQUID-CRYSTAL},
	journal = {Physical Review E},
	volume = {47},
	number = {4},
	year = {1993},
	note = {ISI Document Delivery No.: KZ507Times Cited: 10Cited Reference Count: 18},
	month = {Apr},
	pages = {2954-2957},
	type = {Note},
	abstract = {Molecular-dynamics simulations are used to investigate the dynamical properties of a ferroelectric nematic liquid crystal. The results are also relevant to electrorheological fluids and to ferrofluids. Translational and rotational diffusion constants parallel and perpendicular to the director are reported and discussed. Dipole-dipole reorientational correlation functions are calculated and compared with theoretical models.},
	keywords = {ANISOTROPY, ELECTROSTATIC SYSTEMS, FLUIDS, MOLECULAR-DYNAMICS, PERIODIC BOUNDARY-CONDITIONS, SIMULATION, VISCOSITY},
	isbn = {1063-651X},
	url = {<Go to ISI>://A1993KZ50700094},
	author = {Wei, D. Q. and Patey, G. N.}
}
@article {2759,
	title = {STRUCTURE AND DYNAMICS OF BINARY CLUSTERS},
	journal = {Physical Review Letters},
	volume = {70},
	number = {21},
	year = {1993},
	note = {ISI Document Delivery No.: LC943Times Cited: 29Cited Reference Count: 14},
	month = {May},
	pages = {3283-3286},
	type = {Article},
	abstract = {Phase separation dynamics and structural properties of binary liquid clusters with linear dimensions in the nanometer range are investigated. The demixing process proceeds through incipient domain formation and coarsening processes. Strong density correlations are shown to exist within the resulting phase-separated clusters. The results of this study show that cluster binary mixtures display interesting two-phase phenomena which differ from their bulk-phase analogs.},
	keywords = {LENNARD-JONES CLUSTERS, MOLECULAR-DYNAMICS},
	isbn = {0031-9007},
	url = {<Go to ISI>://A1993LC94300027},
	author = {Clarke, A. S. and Kapral, R. and Moore, B. and Patey, G. and Wu, X. G.}
}
@article {7376,
	title = {FERROELECTRIC LIQUID-CRYSTAL AND SOLID-PHASES FORMED BY STRONGLY INTERACTING DIPOLAR SOFT SPHERES},
	journal = {Physical Review A},
	volume = {46},
	number = {12},
	year = {1992},
	note = {ISI Document Delivery No.: KE871Times Cited: 120Cited Reference Count: 22},
	month = {Dec},
	pages = {7783-7792},
	type = {Article},
	abstract = {Molecular-dynamics simulation results are reported for systems of strongly interacting dipolar soft spheres. Calculations have been carried out along two isotherms and the structure of the liquid-crystal and solid phases obtained is described in detail. It is found that in addition to the ferroelectric nematic phase we previously reported [Phys. Rev. Lett. 68, 2043 (1992)], liquid crystals with columnar order can also be obtained. The model freezes to form a ferroelectric solid which is shown to have a tetragonal I crystal structure The influence of different boundary conditions upon the simulation results is also discussed.},
	keywords = {COMPUTER-SIMULATION, FLUID, MOLECULAR-DYNAMICS, SYSTEMS},
	isbn = {1050-2947},
	url = {<Go to ISI>://A1992KE87100054},
	author = {Wei, D. Q. and Patey, G. N.}
}
@article {7179,
	title = {A MEAN FIELD-THEORY FOR FLUIDS OF MULTIPOLAR PARTICLES IN CONTACT WITH A POLARIZABLE WALL},
	journal = {Journal of Chemical Physics},
	volume = {97},
	number = {6},
	year = {1992},
	note = {ISI Document Delivery No.: JN146Times Cited: 15Cited Reference Count: 27},
	month = {Sep},
	pages = {4372-4379},
	type = {Article},
	abstract = {Fluids of multipolar particles in contact with a semi-infinite polarizable hard wall are considered. A mean field theory which reduces the many-body electrostatic wall-solvent interactions to an effective pair potential is described. The effective potential can be employed in conjunction with the reference hypernetted-chain approximation, or some other integral equation theory, to obtain a self-consistent solution for the wall-solvent correlation function and hence the solvent structure at the interface. Explicit results are given for dipolar hard sphere fluids in contact with walls having dielectric constants ranging from 1 to infinity. For this system, it is shown that contributions to the wall-solvent potential from images of other particles are very important and act strongly against the direct "self-image" interaction.},
	keywords = {ASYMPTOTIC-BEHAVIOR, CHARGED SURFACES, DIPOLAR HARD-SPHERES, INVARIANT EXPANSION, LIQUID WATER, MOLECULAR-DYNAMICS, NONSPHERICAL PARTICLES, ORNSTEIN-ZERNIKE EQUATION, SPHERICAL MODEL, WATER-LIKE PARTICLES},
	isbn = {0021-9606},
	url = {<Go to ISI>://A1992JN14600051},
	author = {Berard, D. R. and Patey, G. N.}
}
