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The conjugate peak refinement algorithm and a quantum-mechanical potential are used to study the proton transfer (PT) reactions between adjacent sites exposed to water through the calculation the minimum energy pathways (MEPs). The MEP calculations have shown that the transition state is highly strained and has involved a supramolecular structure in which fluorescein and the interconnecting water molecules are covalently bonded together and the protons are shared between neighboring oxygens.

The article describes a simple interface for combined quantum mechanical (QM) molecular mechanical (MM) calculations for the system, where the QM and MM regions are connected through covalent bonds. The model is tested with the computation of equilibrium geometries and protonation energies for dozens of molecules, which showed that it is important to maintain local charge-neutrality in the MM region for the accurate calculation of the protonation and deprotonation energies.

Neutron test data on single event effects for a wide range of SRAMs, facilities (monoenergetic and continuum) and energies (thermal to 800 MeV) are compared. Many modern devices are found to be sensitive to thermal neutrons and rates from this source can dominate in many situations. A significant number of devices suffer latchup and the cross-sections increase with operating voltage and beam energy implying that most test facilities will understimate the problem for the natural atmospheric environment. Upset sensitivity at 3-5 MeV varies from 5 to 600 less than at high energies and will be of most significance for sources of fission neutrons. These results are related to current and developing standards. Index Terms--Neutrons, protons, single event effects, standards.

This paper presents a method to estimate the saturated proton upset cross section for 6 T SOI SRAM cells from layout and technology parameters. The calculated proton upset cross section based on this method is in good agreement with test results for our 6 T SOI SRAM cells processed using 0.15 and 0.35 [micro]m technologies. Index Terms--Heavy ion, proton, single event upset, upset cross section.

Simple expressions, based on previous analytical and empirical models for the energy deposited by protons through their p + Si interactions, are proposed for calculating proton induced SEU cross sections from heavy ion cross sections in devices with sub-micron sensitive volumes. Calculations for modern devices yield good agreement with the experiments. The implications on calculating SEU rates in space are discussed. Index Terms--Indirect LET of protons, proton induced SEU, SEU rates in space.

A method that includes explicit electron-proton correlation directly into the nuclear-electronic orbital self-consistent-field framework is described. The nuclear-electronic orbital explicitly correlated Hartree-Fock (NEO-XCHF) method is computationally practical for many-electron systems since only a relatively small number of nuclei are treated quantum mechanically and only electron-proton correlation is treated explicitly.

We report on irradiation induced SEU by high-energy protons and neutrons. The experiments were performed at The (odor) Svedberg Laboratory in Uppsala, Sweden, and at the Weapons Neutron Research (WNR) facility, Los Alamos, USA. A wide range of SRAMs were used to study the differences between proton and neutron induced SEUs at different energies. Index Terms--Neutron, proton, SEU, SRAM, WNR.

A study was conducted to demonstrate a shallow-ridge quantum-cascade laser (QCL) with performance comparable or better than that of deep-ridge QCLs fabricated from the same water. Lateral spreading of the injection current-usually a drawback of shallow-ridge lasers is suppressed by proton implantation into the strain-compensated InGaAs-AlAs active region layers on either side of the ridge.

Four new 9-(2'-hydroxyphenyl)anthracene derivatives were synthesized and their potential excited state intramolecular proton transfer (ESIPT) reaction investigated. The results reveal that it is possible to structurally tune ESIPT in (hydroxyphenyl)anthracenes to either result in a completely reversible reaction or give isolable anthracene addition or rearrangement products.

Several models are explored for the ground-state proton chain transfer pathway between the green fluorescent protein chromophore and its surrounding protein matrix in order to elucidate the mechanistic aspects of this process. The analysis of the minimum energy pathways (MEPs) has revealed a clear evidence of sequential movement of protons in the chain and the ground-state proton chain transfer does not appear to be driven by the movement of the phenolic proton off the chromophore onto the neutral water bridge.

Ab initio methods were used for calculating the proton affinities of 15 chlorophenols. As the liberation of the proton increases, a linear decrease in proton affinities was observed with the electronic density gain on the chlorine atoms.

Theoretical studies for the dynamics of triple proton transfer in the cyclic water trimer are performed by creating a potential energy surface (PES). The results show that the PES of the concerted triple proton transfer in cyclic water trimer can be generated by the molecular mechanics potential functions with the modified MM3 force field parameters and a limited number of high-level electronic structure calculations.

The development of the multistate empirical valence bond (MS-EVB) force field for describing the aqueous phase deprotonation of amino acids, specifically histidine and glutamic is presented. The MS-EVB model for amino acids consists of a modified AMBER force field for the description of EVB states and functional forms and associated parameters for the description of the couplings among these states.

The long-term goal of theoretically characterizing kinetics of long-range proton transfer in biomolecular pumps such as cytochrome c oxidase, which might exhibit interesting kinetic properties as required by their biological function are presented. The results suggest that coordinates based on the modified center of excess charge can be used as the reaction coordinate for computing a meaningful potential of mean force for long-range proton transfer.

The dynamics of the excited-state intramolecular proton transfer of 10-hydroxybenzo[h]quinoline (10-HBQ) and the associated coherent nuclear motion were investigated. It was found that the nuclear motion of this lowest-frequency mode involves a large displacement of the OH group toward the nitrogen site as well as in-plane skeletal deformation that assists the oxygen and nitrogen atoms to come closer to each other.

An extended model for intermolecular excited-state proton transfer (ESPT) to the solvent is developed on the basis of pump-probe measurements of both the POH and RO(super -) signals. The model includes two reactive steps followed by a diffusion-assisted step.

The quantum chromodynamics (QCD) spin structure of the proton is reviewed. The process of understanding the spin structure of the proton produces an insight into QCD dynamics and the interplay between spin and chiral or axial U(1) symmetry breaking in QCD.

The proton dynamics of crystalline bisquaric acid (H2BSQ) in terms of the temperature and frequency dependence of its permittivity is investigated. It was found that the dielectric response of the H2BSQ crystal exhibited two-step changes.

The behaviors of double proton transfer occurring in a representative glycinamide-formamidine complex are investigated employing the B3LYP/6-311++G level of theory. The differences between model system and adenine-thymine base pair are discussed briefly.

Reichardt's dye (RD) on a highly hydrated HMS surface strips a proton from a SiOH in a patch of silanols, in the presence of polar molecules acting as solvents, so becoming colorless. A base stronger than RD captures the proton, giving rise to the appearance of color.

The different possible proton-ordered structures of ice Ih for an orthorombic unit cell with 8 water molecules were derived. The mose important parameters to determine the lattice energies were found to be the distributions of water dimer H-bonded pair conformations, in an intricate manner.

Short-range ferroelectric order is postulated to explain unusual one-dimensional dielectric response in ferroelectric 1,4-diazabicyclo[2.2.2]octane. The phenomenon arising from a self-discrimination of the crystal ionic structure strongly resembles the behavior of ferroelectric relaxors induced by an artificial compositional disorder.

Time-resolved and steady-state emission characterization of 10-hydroxycamptothecin reveals a rich but less complex proton-transfer behavior. The electronic effect of the additional electron-withdrawing ring makes the excited state both less basic and more acidic than the parent.

A new synthetic approach to the formation of ultrathin polymer films was developed. The subsequent recombination of carbon radicals gives a cross-linked polymer thin film.

The transport properties of presently available and emerging materials that have the potential to be used as the electrolyte for fuel cells are discussed. The current understanding of the underlying elementary processes and a phenomenological description of the resulting macroscopic transport phenomena are mainly focused.

The materials requirements for advanced alternative proton exchange membranes for fuel cells, assess recent progress in this area, and provide directions for the development of next generation materials are summarized. The synthesis of polymeric materials that have attached ion-conducting groups are described.

The energetic fitness of histidine in its three protonation states is investigated. Molecular mechanics calculations are used for this purpose.

The extent of hydrogen exchange within multiply charged solvent-free protein ions was investigated using a small model protein. The site-specific backbone amide protection data was obtained using protein ion fragmentation in the gas phase and compared with the available NMR data.

Studies done on the effect of replacing Glu-L212 with Asp and Asp-L213 with Glu in the Rhodobacter sphaeroides reaction center by monitoring the light-induced FTIR absorption changes associated with the photoreduction of QB is presented. The findings of the study indicate that there is a proton sharing among carboxylic acids in a system very similar to the native reaction center, which differs in the absorption frequency of protonating carboxylic acids and in the extent of proton sharing.

Catalytic cycle of carbonic anhydrase III is considered to explore the nature of proton transfer (PT) in proteins while focusing special attention on free energy relationship. A general framework for the study of proton translocation in proteins is reported to be the outcome of this approach.

High-level calculation (G2+) is used to characterize the gas phase potential energy surfaces of the nonidentity proton transfer reactions of a series of simple anions (H (super -), CH (sub 3)(super -), NH (sub 2), OH (super -), F (super -), Si H (sub 3)(super -), PH (sub 2)(super -), SH (super -), C1 (super -), HCC (super -) and NC (super -) with their conjugate acids. The studies of the asymmetric proton transfers indicate that the surface take on a shape that is a hybridization of the shapes of the parent, symmetric proton transfers.

Quantum chemical methods are applied to study the stages of the proton transfer in water wires attached to molecular walls containing the side chains of His and Asp residues. The results of calculations show that the only transition state structure found on the proton-transfer route refers to the stage of proton detachment from the N(sub epsilon) atom of the imidiazole ring to the neighboring water molecules.

The study was done on the energetic of proton transfer reactions in carbonic anhydrase (CA) using an active site model. The study reveals that the energetic obtained from the current work are approximately consistent with the experimental estimates and the proton transfer reaction in Carbonic Anhydrase (CA) is sensitive to the structure of water bridge.

The reactions of H atoms with methane, ethane and chlorinated methanes and ethanes are examined by computational techniques. A method to predict reaction rate constants based on the use of isodesmic reactions for transition phases is developed and presented.

Formation of electrical isolation in n- and p-type In(sub 0.49)Ga(sub 0.51)P epitaxial grown on semi-insulating GaAs substrates was investigated using proton or helium ion irradiation. Thermal stability of the isolation during postirradiation annealing was found to increase with accumulation of the ion dose.

A new scanning electrochemical microscopy proton feedback method (SECM) was developed. This investigated the lateral proton diffusion at phospholipid assemblies.

The proton translocation along ammonia wires is investigated in 7-hydroxyquinoline.(NH3)(sub n) clusters, both experimentally by laser spectroscopy and theoretically by Hartree-Fock and density functional theory (DFT) calculations. It was seen that the step with the highest barrier involves a complex proton transfer mechanism, involving structural reorganization and large-scale diffusive motions of the cluster.

A study of the intramolecular proton transfer controlled by laser pulses in which the motion of proton in a molecule was treated by one-dimensional asymmetric double-well potential while the control of the motion of a proton, pi-pulse approach, stimulated Raman adiabatic passage (STIRAP), and a chirping technique were applied to the system is presented. The results show that in the pi-pulse approach, the conditions of complete population inversion were determined for sequential and simulations irradiation of two laser fields.

A study of the possibility of observing a spontaneous proton transfer (PT) between a proton donor AH and a proton acceptor B is analyzed using a suitable model systems, the hydrogen bond complexes between HF, HCl, and HBr and a set of bases which covers a large range in the gas-phase basicity scale is presented. The results show that to obtain strong hydrogen bonded complex, a very polarized A-H bond, and a sufficiently strong Lewis base, B, are necessary.

A study of the quantum effects on the proton-transfer reaction in the N2H7 (super +) cluster using the classical ab initio Monte Carlo method and a one dimensional model for the quantum wave packet dynamics on the ab initio MP2/6-31 +G (super *) potential energy surface is presented. The results show that the vibrational frequency for the N-H stretching mode which corresponds to the proton transfer is estimated to be 706.7 cm (super -1) by including proton quantum effects in contrast with 2100.1 cm (super -1) obtained by the conventional ab initio MO method for the C (sub 3v) structure.

The nanosecond emission study of the monoanion-dianion excited-state proton exchange reaction of flurorescein is carried out in the pH range 6-10. The kinetic mechanisms, the specific rate constants for the excited-state proton reactions, and lifetimes of the monoanions and dianions are reported by analyzing the records of nanosecond emission graphs with high precision methods.

The fluorescence kinetic constants are measured as functions of wavelength, pH, hydrogen isotope, and temperature to understand proton transfers involved in the excited-state tautomerization of aqueous 6-hydroquinoline. It is found to be important in the deprotonation of the enol group and in the migration of a hydrated proton cluster.

A picosecond absorption spectroscopy was employed in determining the dynamics of proton transfer within a variety of substituted benzophenones/N,N-dimethylaniline in a series of alkanenitrile solvents. A correlation of the rate constants for proton transfer with driving force reveals a normal region and an inverted region for proton transfer.

Research is done on ab inito full geometry optimizations, which are carried out for the ground and first excited singlet electronic states of the 7-azaindole dimer, a well-known prototype of the DNA base pairs. In conclusion, the transition state energies are also lower, a result that points to an increase in the rate constant of the process in condensed phase.

Research is done on a divide-and-conquer method by which an accurate static and induced multipole representation of the electrostatic potential of a protein can be generated using ab initio electronic structure theory, which is presented. It is suggested that the experimentally calculated (identical) pK(sub a)s of Tyr20 and Lys55 might be identical for the same reason.

An examination is done on femtosecond transient absorption spectra of molecules in solution change when an ultrafast reaction creates a new product state, and coherent optical processes complicate the spectra during the pump pulse. In conclusion, the spectra of all species are obtained and decomposed.

The reversible proton dissociation and geminate recombination of photoacids as a function of temperature in monols, diols, and glycerol is studied. The experimental data are analyzed and solved numerically.

The intramolecular proton transfer in the amino acid glycine in aqueous solution is studied. It is observed that this system is nonequilibrium solvation, where proton-transfer step is fast and the solvent relaxes afterward.

A model description for the acid-base proton-transfer reaction between HCl and H2O in a hydrogen-bonded complex dissolved in a low polarity solution is developed. The fundamental nature of this proton-transfer reaction is investigated with particular emphasis on the effects of quantization of the proton and hydrogen-bond vibrations.