New challenges in quantum chemistry: Quests for accurate calculations for large molecular systems.

The mobility of simple ions such as alkali–metal and halide ions at room temperature shows two anomalies. Firstly, there are maxima in mobilities as a function of ion size for both positive and negative ions and, secondly, the maximum for negative ions occurs at a larger ionic radius than the maximum for positive ions. Theoretical treatments of this problem are reviewed and it is concluded that a molecular treatment of the system is needed to understand the results. Computer simulation using the simple point charge model (SPC/E) for water reproduced the observations and is used to discuss the application of theories. In particular, the nature of the first solvation shell is correlated with ion mobility. Simulation reveals a further anomaly, namely that if the charge is removed from a large ion, then it moves more slowly. This is interpreted as the result of formation of a solvent cage around the hydrophobic solute. The changes in local structure resulting from changes in charge and size also affect the solvation thermodynamics. Simulations show that the solvation entropy has a double maximum when viewed as a function of charge. The local minimum near zero charge is interpreted as being due to hydrophobic order, and the maxima as the result of structure breaking. This double maximum in the entropy of solvation is a signature of the hydrophobic cage effect. Comparisons are made between ion mobilities in liquid water at ambient and supercritical conditions.

International Journal of Modern Physics BVol. 06, No. 23n24, pp. 3687-3693 (1992) I. CLUSTERS: Formation, Structure and Phase TransitionsNo AccessAB INITIO ELECTRONIC STRUCTURE CALCULATIONS ON DODECAHEDRAL CLUSTERS OF TWENTY WATER MOLECULES AND THEIR GAS-PHASE CLATHRATES WITH ALKALI METAL CATIONSJ. Cioslowski and A. NanayakkaraJ. CioslowskiDepartment of Chemistry and Supercomputer Computations Research Institute, Florida State University, Tallahassee, Florida 32306–3006, USA and A. NanayakkaraDepartment of Chemistry and Supercomputer Computations Research Institute, Florida State University, Tallahassee, Florida 32306–3006, USAhttps://doi.org/10.1142/S0217979292001754Cited by:10 PreviousNext AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail You currently do not have access to the full text article. Recommend the journal to your library today! FiguresReferencesRelatedDetailsCited By 10Hydrated Alkali Metal Ions: Spectroscopic Evidence for ClathratesRichard J. Cooper, Terrence M. Chang and Evan R. Williams10 July 2013 | The Journal of Physical Chemistry A, Vol. 117, No. 30Interaction between OH Radical and the Water InterfaceShiyu Du and Joseph S. Francisco3 May 2008 | The Journal of Physical Chemistry A, Vol. 112, No. 21Theoretical studies of Na(H2O)19–21+ and K(H2O)19–21+ clusters: explaining the absence of magic peak for Na(H2O)20+Arshad Khan1 Apr 2004 | Chemical Physics Letters, Vol. 388, No. 4-6On the interactions between atmospheric radicals and cloud droplets: A molecular picture of the interfaceQicun Shi, Stephen D. Belair, Joseph S. Francisco and Sabre Kais6 August 2003 | Proceedings of the National Academy of Sciences, Vol. 100, No. 17The effect of ions on solid–liquid phase transition in small water clusters. A molecular dynamics simulation studyAndrei V. Egorov, Elena N. Brodskaya and Aatto Laaksonen8 Apr 2003 | The Journal of Chemical Physics, Vol. 118, No. 14Complexation of Li+, Na+, and K+ by water and ammoniaK Laidig1 Feb 2000 | Coordination Chemistry Reviews, Vol. 197, No. 1Dynamics of a Highly Charged Ion in Aqueous Solutions: MD Simulations of Dilute CrCl 3 Aqueous Solutions Using Interaction Potentials Based on the Hydrated Ion ConceptJosé M. Martínez, Rafael R. Pappalardo, Enrique Sánchez Marcos, Keith Refson and Sofía Díaz-Moreno et al.2 April 1998 | The Journal of Physical Chemistry B, Vol. 102, No. 17Theoretical studies of structures and stabilization energies of (H2O)26, (H2O)27 and (H2O)28 pentakaidecahedral clustersArshad Khan1 Aug 1996 | Chemical Physics Letters, Vol. 258, No. 5-6Theoretical studies of tetrakaidecahedral structures of (H2O)24, (H2O)25 and (H2O)26 clustersArshad Khan1 May 1996 | Chemical Physics Letters, Vol. 253, No. 3-4Quantum-Mechanical investigation of large water clustersKarl N. Kirschner and George C. Shields12 Feb 1994 | International Journal of Quantum Chemistry, Vol. 52, No. S28 Recommended Vol. 06, No. 23n24 Metrics History PDF download

Research Highlights

A ϕ/ψ conformational energy map of a model alanyl dipeptide is first drawn using the SIBFA (Sum of Interactions Between Fragments Ab initio computed) procedure [N. Gresh, P. Claverie and A. Pullman (1979) International Journal of Quantum Chemistry Symposium, Vol. 13, pp. 243–253; N. Gresh, P. Claverie and A. Pullman (1982) International Journal of Quantum Chemistry, Vol. 22, pp. 199–215; N. Gresh, P. Claverie and A. Pullman (1984) Theoretical Chimica Acta, Vol. 66, pp. 1–20; N. Gresh, P. Claverie and A. Pullman (1985) Theoretical Chimica Acta, Vol. 67, pp. 11–32; N. Gresh, A. Pullman and P. Claverie (1985) International Journal of Quantum Chemistry, Vol. 28, pp. 757–771; N. Gresh, P. Claverie and A. Pullman (1986) International Journal of Quantum Chemistry, Vol. 29, pp. 101–118; N. Gresh (1995) Journal of Computational Chemistry, Vol. 16, pp. 856–882; N. Gresh and D.R. Garmer (1996) Journal of Computational Chemistry, Vol. 17, pp. 1481–1495; N. Gresh, M. Leboeuf and D.R. Salahub (1994) in Modelling the Hydrogen Bond, Vol. 569, American Chemical Society Symposia, Smith, D.A., Ed., pp. 82–112; N. Gresh (1997) Journal de Chim.-Phys. (Paris), Vol. 94, pp. 1365–1416]. A new formulation of the intramolecular (conformational) energy is used, consistent with the refinements that were recently published for the intermolecular interaction energies in joint SIBFA/ab initio supermolecule Self-Consistent Field/Moller-Plesset (SCF/MP2) and Density Functional Theory (DFT) studies of cation-ligand [see Gresh (1995) and Gresh and Garmer (1996) above], and H-bonded [see Gresh et al. (1994) above] complexes. The accuracy of the procedure is assessed, on fourteen conformers selected from the map, by comparing their relative conformational energies with those obtained from SCF/MP2 and DFT computations. Conformational energy maps are then recomputed in the presence of water, dimethyl sulfoxide, chloroform, and carbon tetrachloride, the solvation energies being computed with the Continuum reaction field procedure due to J. Langlet et al. [(1988) Journal of Physical Chemistry, Vol. 92, pp. 1617–1631], and recently integrated into SIBFA [J. Langlet, N. Gresh and C. Giessner-Prettre (1995) Biopolymers, Vol. 36, pp. 765–780]. Such an integrated procedure is next extended to a comparison of the relative stabilities of, on the one hand, the competing types of β-turns (I, I′, II, II′) that are prevalent in Ala/Gly-based model tetrapeptides, and, on the other hand, α- vs 310-helices in alanine oligomers. © 1998 John Wiley & Sons, Inc. Biopoly 45: 405–425, 1998

The origins of electronic spectral broadening in solutions, glasses and proteins are discussed via three pulse stimulated echo peak–shift measurements. Spectral densities for dye molecules in polar solutions are presented and discussed in terms of molecular models for the dynamics. The breakdown of the harmonic bath picture at low frequencies is presented. Finally, echo measurements on light harvesting complexes of purple bacteria are presented and it is shown that the energy transfer timescale can be obtained from peak–shift measurements.

The virial stress is the most commonly used definition of stress in discrete particle systems. This quantity includes two parts. The first part depends on the mass and velocity (or, in some versions, the fluctuation part of the velocity) of atomic particles, reflecting an assertion that mass transfer causes mechanical stress to be applied on stationary spatial surfaces external to an atomic‐particle system. The second part depends on interatomic forces and atomic positions, providing a continuum measure for the internal mechanical interactions between particles. Historic derivations of the virial stress include generalization from the virial theorem of Clausius (1870) for gas pressure and solution of the spatial equation of balance of momentum. The virial stress is stress‐like a measure for momentum change in space. This paper shows that, contrary to the generally accepted view, the virial stress is not a measure for mechanical force between material points and cannot be regarded as a measure for mechanical stress in any sense. The lack of physical significance is both at the individual atom level in a time‐resolved sense and at the system level in a statistical sense. It is demonstrated that the interatomic force term alone is a valid stress measure and can be identified with the Cauchy stress. The proof in this paper consists of two parts. First, for the simple conditions of rigid translation, uniform tension and tension with thermal oscillations, the virial stress yields clearly erroneous interpretations of stress. Second, the conceptual flaw in the generalization from the virial theorem for gas pressure to stress and the confusion over spatial and material equations of balance of momentum in theoretical derivations of the virial stress that led to its erroneous acceptance as the Cauchy stress are pointed out. Interpretation of the virial stress as a measure for mechanical force violates balance of momentum and is inconsistent with the basic definition of stress. The versions of the virial‐stress formula that involve total particle velocity and the thermal fluctuation part of the velocity are demonstrated to be measures of spatial momentum flow relative to, respectively, a fixed reference frame and a moving frame with a velocity equal to the part of particle velocity not included in the virial formula. To further illustrate the irrelevance of mass transfer to the evaluation of stress, an equivalent continuum (EC) for dynamically deforming atomistic particle systems is defined. The equivalence of the continuum to discrete atomic systems includes (i) preservation of linear and angular momenta, (ii) conservation of internal, external and inertial work rates, and (iii) conservation of mass. This equivalence allows fields of work‐ and momentum‐preserving Cauchy stress, surface traction, body force and deformation to be determined. The resulting stress field depends only on interatomic forces, providing an independent proof that as a measure for internal material interaction stress is independent of kinetic energy or mass transfer.

Theoretical Study on Reaction Pathways of Methyl Radical with Ethylamine

This issue of the International Journal of Quantum and Computational Chemistry consists of contributions coming from the 12th V.A. Fock Meeting on Quantum and Computational Chemstry held in Kazan (Republic of Tatarstan, Russia) located on the banks of the Wolga river from 19 to 23 October 2009. This was the annual meeting of the series of the V.A. Fock Meetings of which the first was held in December of the year 1998 in celebration of the 100-th anniversary of the birth of Prof. V.A. Fock of the St. Petersburg (Leningrad) University, whose works such as the ubiquitous Hartree–Fock approximation are central to physical chemistry and chemical physics. These Meetings are attended by the established researches as well as by younger scientists from leading reasearch centers of Russia. The 2009 meeting was attended by participants from Moscow, St. Petersburg, Krasnodar, Bashkir State Universities, Kurnakov Institute of General and Inorganic Chemistry of RAS, Boreskov Institute of Catalysis of SB RAS (Novosibirsk), and many others. The Meetings of this Series are sponsored by the Scientific Council on Chemical Structure and Reactivity of RAS. The 2009 Meeting as the previous ones was also supported by the Section of Quantum and Computational Chemistry at the D.I. Mendeleev Chemical Society of Russia. Financial support for this activity comes from the Russian Foundation for Basic Research (Grant No. 09-03-06076). The topic presented at the Fock Meeting range from theoretical foundations of quantum chemistry to its applications related to structure dynamics and reactivity and from diatomics to solid state and biomolecules. The applications involve small molecules as well as biomolecules and condensed-phase systems. This Meeting would be not possible without kind support and assistance of many people. Among them Prof. A.L. Buchachenko—the chairman of the Division for Computational Chemistry at the Mendeleev Society and the chairman of the RAS Council on Chemical Structure and Reactivity. Key roles were played by the Rector of the Kazan State technological University Prof. German S. D'yakonov and the chairman of the local Organizing Committee Prof. R.R. Nazmutdinov, whose solutions to all problems made the sessions of the Meeting successful and comfortable. Finally, Prof. Yngve Öhrn (Florida, USA) is acknowledged for his devotion in organizing the preparation and publication of these Proceedings in the International Journal of Quantum Chemistry.

Phosphor materials enable the wavelength conversion to realize the full-color white emission light-emitting diodes (LEDs). So far much effort has been devoted to the design and discovery of novel LED phosphors for solid state lighting. Understanding and exploring the structural design principles of the inorganic hosts are necessary for the discovery of novel LED phosphors. Our recent work focuses on the discovery of new phosphor materials based on the structural evolution and the crystallographci sites engineering. Firstly, photoluminescence tuning can be realized via the cation substitution on one site, and hereby we have discovered several types of M2SiO4-based and M3(PO4)2-based phosphors with tunable emission for white LEDs.1-2 Secondly, we have recently proposed the concept of “chemical unit cosubstitution” as one potential design scheme, and the chemical unit cosubstitution strategy is applied to the melilite structure class designing the Ca2(Al1−x Mg x )(Al1−x Si1+x )O7:Eu2+ solid solution phosphor via the [Mg2+−Si4+] for [Al3+−Al3+] cosubstitution.3 We also design the La5Si3O12N phase from La5Si2BO13 via the [B3+−O2−] by the [Si4+−N3−] cosubstitution.4 Thirdly, we have proposed a new insight into the design of the isostructural phases via the filling of M+ in the void channels of the Mg2Al4Si5O18 phase, so that the charge balance can be kept while the chemical composition varied, and this strategy will be also efficient in other porous inorganic hosts.5 Finally, we have recently studied the NaScSi2O6-based phosphor from CaMgSi2O6-based phosphor via the chemical unit cosubstitution of [Na+–Sc3+] for [Ca2+-Mg2+] unit.6 Further studies show that the isostructural solid-solution of (CaMg) x (NaSc)1-x Si2O6 (0 < x < 1) can be formed, in which cation nanosegregation enables the presence of dilute Eu2+ at two centers and their intensities are linearly proportional to x, so that it represents a new cation nanosegregation tuning of photoluminescence for the exploration of color-tunable phosphor for white LEDs.7-8 References [1] Z. G. Xia*, et. al., Inorganic Chemistry, 2015, 54, 7684-7691. (Cover paper) [2] Z. G. Xia*, et. al., Journal of Physical Chemistry C, 2015, 119, 2038–2045. [3] Z. G. Xia*, et. al., Journal of the American Chemical Society, 2015, 137, 12494-12497. [4] Z. G. Xia*, et. al., Journal of Physical Chemistry C, 2015, 119, 9488–9495. [5] Z. G. Xia*, et. al., Scientific Reports, 2015, 5, 12149. [6] Z. G. Xia*, et. al., Journal of Physical Chemistry C, 2013, 117, 20847−20854. (Cover Paper) [7] Z. G. Xia*, et. al., Scientific Reports, 2013, 3, 3310-3310-7. [8] Z. G. Xia*, et. al. Journal of the American Chemical Society, 2016, 138, 1158-1161.

A Comprehensive Treatise on Inorganic and Theoretical Chemistry

The elementary requirements for energy transfer in a photosynthetic antenna are discussed. Energy migration between chlorophyll molecules in the PSI antenna reaction centre complex was modelled using a geometry based on the recent X–ray structure. The migration is trap–limited and an intrinsic electron transfer rate constant of 1.3 ps−1 was obtained by modifying the model to account for experimental results obtained from antennae of different sizes. Exciton coupling between pairs of Chlorophyll molecules was calculated and it is found that to prevent self–quenching their interplanar separation must be greater than or equal to 5 A. In the PSI reaction centre, exciton coupling between adjacent chlorophylls was found to be around 300 cm−1 with no particularly large value between the special pair being necessary to describe the experimentally observed transient spectra of P +700− P 700 and A −− A . Electrochromic interaction is particularly important in reproducing the A −− A spectrum.

The intrinsic relative preferences of XX, XY and YY interactions between functional groups X and Y can be obtained by considering a set of onedimensional inclusion compounds containing guest molecu...

Recent developments in microscopic instrumentation and probes have allowed the observation and manipulation of the movement of membrane proteins and lipids in the plasma membrane at the level of single molecules. These experiments are performed by tracking small colloidal gold particles attached to specific membrane proteins and lipids (single particle tracking) (Jacobson et al., 1995 ; Sheets et al., 1995 ; Kusumi and Sako, 1996 ; Saxton and Jacobson, 1997 ) or by dragging particle–protein complexes along the surface of the plasma membrane using laser tweezers (also termed an “optical trap” or OT) (Edidin et al., 1991 ; Kusumi and Sako, 1996 ; Kusumi et al., 1998 ). In optimal cases, a single protein molecule is attached to a 40-nm-diameter colloidal gold probe (Tomishige et al., 1998 ). These single molecule experiments have demonstrated that most membrane-spanning proteins do not undergo simple diffusion, but that a significant number are locally slowed or stopped, some are temporarily confined, and others are transported unidirectionally (Kusumi et al., 1993 ; Sheets et al., 1997 ; Sako et al., 1998 ; Simson et al., 1998 ). Previously, these processes had not been observed, because the methods used, e.g., fluorescence recovery after photobleaching, recorded the ensemble-averaged behavior of a large number of molecules. The underlying cellular mechanisms that induce nonrandom diffusion have remained largely unknown; however, we and others found that properties of the membrane skeleton network fundamentally affect the movement and distribution of certain membrane proteins, such as transferrin receptor, α2-macroglobulin receptor, MHC class I molecules, E-cadherin, and band 3, through corralling and binding effects imposed by the membrane skeleton network (Edidin et al., 1991 ; Luna and Hitt, 1992 ; Kusumi et al., 1993 ; Sako and Kusumi, 1994 , 1995 ; Sako et al., 1998 ; Tomishige et al., 1998 ). The results are particularly clear with band 3 in human erythrocyte ghost membranes, where the specimen consists of a lipid bilayer and its underlying membrane skeleton, which has been biochemically and biophysically well characterized (Golan, 1989 ; Bennett, 1990 ; Bennett and Gilligan, 1993 ; Mohandas and Evans, 1994 ). The results obtained by these studies support a “membrane skeleton fence model” in which the cytoplasmic portion of a membrane protein collides with the membrane skeletal “meshwork” because of steric hindrance, thus resulting in the temporal confinement of the protein within the mesh (compartment, Figure ​Figure1A).1A). Membrane proteins escape from these compartments and hop to adjacent ones because of the dynamic properties of the membrane skeleton. We predict that time-dependent fluctuations in the distance between the membrane and the skeleton are large or the membrane–skeleton network connections form and break continuously, as expected in a chemical equilibrium, providing membrane proteins with the opportunity to pass through the mesh barrier. In the case of band 3, macroscopic diffusion within the erythrocyte membrane occurs as the result of a series of such intercompartmental hops. Figure 1 (A) The model to explain the confined diffusion of band 3 in the membrane (the membrane skeleton fence model). (B) Movement of gold particles attached to band 3 in the erythrocyte membrane, observed with a temporal resolution of 8 ms (4 times greater ... The scientific content of this work has been published previously (Tomishige et al., 1998 ), and the purpose of the present essay is to give the reader a glimpse of the raw data from this study, as recorded by both normal and high-speed video microscopy. We hope the video sequences attached to this article will help the viewing audience develop a feel for how band 3 interacts with the membrane skeleton and undergoes intercompartmental hop diffusion within the erythrocyte ghost membrane.

Surface Review and LettersVol. 04, No. 04, pp. 757-770 (1997) ReviewsNo AccessADSORPTION OF WATER ON NaClGEORGE E. EWING and STEVEN J. PETERSGEORGE E. EWINGDepartment of Chemistry, Indiana University, Bloomington, IN 47405, USA and STEVEN J. PETERSDepartment of Chemistry, Indiana University, Bloomington, IN 47405, USAhttps://doi.org/10.1142/S0218625X97000742Cited by:17 PreviousNext AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail FiguresReferencesRelatedDetailsCited By 17Nanoparticle-assisted acceleration of laser-irradiated low-density He ionsEva Klimešová, Olena Kulyk, Laura Dittrich, Jakob Andreasson and Maria Krikunova27 December 2021 | Physical Review A, Vol. 104, No. 6Adsorption Capacities of Hygroscopic Materials Based on NaCl-TiO 2 and NaCl-SiO 2 Core/Shell ParticlesMarie Bermeo, Nabil El Hadri, Florent Ravaux, Abdelali Zaki and Linda Zou et al.13 Feb 2020 | Journal of Nanotechnology, Vol. 2020Influence of stearic acid coating of the NaCl surface on the reactivity with NO 2 under humidityS. Sobanska, J. Barbillat, M. Moreau, N. Nuns and I. De Waele et al.1 January 2015 | Physical Chemistry Chemical Physics, Vol. 17, No. 16Impacts of Surface Adsorbed Catechol on Tropospheric Aerosol Surrogates: Heterogeneous Ozonolysis and Its Effects on Water UptakeLaurie A. Woodill, Erinn M. O’Neill and Ryan Z. Hinrichs1 July 2013 | The Journal of Physical Chemistry A, Vol. 117, No. 27Interfacial Dushman-like Chemistry in Hydrated KIO 3 Layers Grown on KIMatthew A. Brown, Paul D. Ashby, Maria J. Krisch, Zhi Liu and B. Simon Mun et al.29 July 2010 | The Journal of Physical Chemistry C, Vol. 114, No. 33A critical assessment of theoretical methods for finding reaction pathways and transition states of surface processesJiří Klimeš, David R Bowler and Angelos Michaelides3 February 2010 | Journal of Physics: Condensed Matter, Vol. 22, No. 7Bromine Enrichment in the Near-Surface Region of Br-Doped NaCl Single Crystals Diagnosed by Rutherford Backscattering SpectrometryM. Hess, U. K. Krieger, C. Marcolli, T. Huthwelker and M. Ammann et al.27 April 2007 | The Journal of Physical Chemistry A, Vol. 111, No. 20Influence of multiple reflections on transmission through a stack of platesW. L. Schaich, George E. Ewing and Robert L. Karlinsey20 September 2006 | Applied Optics, Vol. 45, No. 27Surface Adsorbed Water on NaCl and Its Effect on Nitric Acid Reactivity with NaCl PowdersSutapa Ghosal and John C. Hemminger24 August 2004 | The Journal of Physical Chemistry B, Vol. 108, No. 37Thin Film Water on Insulator SurfacesGeorge E. Ewing, Michelle Foster, Will Cantrell and Vlad Sadtchenko1 Jan 2003Adsorption of water on the NaCl(001) surface. II. An infrared study at ambient temperaturesMichelle C. Foster and George E. Ewing15 Apr 2000 | The Journal of Chemical Physics, Vol. 112, No. 15Water content and morphology of sodium chloride aerosol particlesDavid D. Weis and George E. Ewing1 September 1999 | Journal of Geophysical Research: Atmospheres, Vol. 104, No. D17Water adsorption by hydrophobic organic surfaces: Experimental evidence and implications to the atmospheric properties of organic aerosolsElan Thomas, Yinon Rudich, Sofia Trakhtenberg and Rachel Ussyshkin1 July 1999 | Journal of Geophysical Research: Atmospheres, Vol. 104, No. D13The Reaction of Nitrogen Dioxide with Sea Salt AerosolDavid D. Weis and George E. Ewing9 June 1999 | The Journal of Physical Chemistry A, Vol. 103, No. 25Effect of Water on the HNO 3 Pressure Dependence of the Reaction between Gas-Phase HNO 3 and NaCl SurfacesSutapa Ghosal and John C. Hemminger9 June 1999 | The Journal of Physical Chemistry A, Vol. 103, No. 25Measurements of the H 2 SO 4 mass accommodation coefficient onto polydisperse aerosolA. Jefferson, F. L. Eisele, P. J. Ziemann, R. J. Weber and J. J. Marti et al.1 August 1997 | Journal of Geophysical Research: Atmospheres, Vol. 102, No. D15H2O on NaCl: From Single Molecule, to Clusters, to Monolayer, to Thin Film, to DeliquescenceGeorge E. Ewing Recommended Vol. 04, No. 04 Metrics Downloaded 18 times History Received 14 November 1996 PDF download

Theoretical Study of the Formation Methane in the Reaction of Methyl Radical with Propanol-2