bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental and calculational consequences of phases in molecules with multiple conical intersections
Authors: Englman R. , Yahalom A. , Baer M. , Mebel A. M. 
Published: February 2003

AbstractWe set up a theoretical model for treating several degeneracies between two adjacent potential energy surfaces in molecular systems, e.g., cases of four (or more) conically intersecting degeneracies, located in a plane formed by two‐fold molecular displacement coordinates, in trigonal (or cubic) symmetry and twin conical intersections (CIs) for molecules with two‐fold symmetries. When the system circles (in a time‐variant manner) entirely inside or entirely outside these CIs, it picks up phases (the geometric phases) that are zero or 2Nπ. Here, N is (to a good approximation) an integer whose value depends on the Hamiltonian for the system, on the distance of circling from the CI, and on the speed of circling. For the adiabatic (slow circling) limit, we develop a simple algebraic‐graphical method that yields the value of N in each case. Even in this limit, the value of N is model dependent and is not uniquely given by the number of CIs that are circled. Further, we suggest an experiment (based on a pump‐probe method) for tracing the time development of a system that is subject to a periodically varying field carrying it around the CI. The experiment leads to relations between the spectroscopic transition strengths and state amplitudes, such that the (open‐path) phases are fully given (including the additive 2Nπ term and excluding the dynamic phase). Finally, we compare geometric phases that differ by integral multiples of 2π and, therefore, cannot be distinguished by phase interference. We show that the different cases have, nevertheless, observational correlates in the number of times that zero or unity occurs in a wave function component amplitude during circling. The rules of correspondence are given. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
BSSE‐free description of intermolecular force constants in hydrogen fluoride and water dimers
Authors: Bende A. , Knapp‐Mohammady M. , Suhai S. 
Published: February 2003

AbstractTheoretical studies have been performed to calculate the force constants and harmonic vibrational frequencies in the hydrogen fluoride and water dimers. The calculations have been undertaken both at the Hartree–Fock and correlated (second‐order Møller–Plesset perturbation theory) levels of theory using several different basis sets ranging from the weak to the intermediate. The basis set superposition error (BSSE) has been excluded by using the chemical Hamiltonian approach. The results show that the BSSE influence is significant in the force constants and harmonic vibrational frequencies even if electron correlation is accounted for, so removing the BSSE is important. The results are compared with those obtained by the basis independent density‐functional tight‐binding method. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
Optimized partitioning in PT: Application for the equation of motion describing ionization processes
Authors: Szabados Ágnes , Surján Péter R. 
Published: February 2003

AbstractIn computing ionization potentials via perturbative solution of the equation of motion for the ionization operator, we apply the technique of “partitioning optimization” elaborated recently for the calculation of correlation energy. Sample calculations indicate that second‐order results may improve if the partitioning is optimized. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
Comparison of the imaginary and complex absorbing potentials using multistep potential method
Authors: Halász G. J. , Vibók Á. 
Published: February 2003

AbstractIn this article, the reflection and transmission of plane waves are examined from “negative imaginary” (NIP) and “true complex” absorbing potentials (CAP). Comparisons have been made between these two types of potentials using our multistep potential method. The results showed that, except for a few cases, the CAPs give significantly better values for the absorption than those given by the NIPs. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
Interatomic exchange energy components
Authors: Mayer I. , Hamza A. 
Published: February 2003

AbstractThe diatomic energy components obtained in the framework of the recent chemical energy component analysis can be further decomposed into terms of different physical origins, reflecting electrostatic, exchange, overlap, etc., effects. The proper definition of the interatomic exchange energy component represented a nontrivial task, however. Here, we considered two possible definitions of that quantity. The first is introduced following the definition of the intermolecular exchange. This seemingly straightforward analogy has been found misleading—it leads to a quantity that vanishes in the limit of an NDO‐type integral approximation. The correct definition has been found by analyzing the exchange energy components connected with the delocalized bonding orbitals in a diatomics and generalizing the interatomic exchange energy contribution obtained in this simplest case by the analogy to the respective Coulomb energy component. This definition is adequate for all types of theories, has the correct asymptotic behavior, and exhibits the expected connections with the bond order indices. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
Density‐dependent effective action for electron systems
Authors: Polonyi J. , Sailer K. 
Published: February 2003

AbstractThe density‐dependent effective action is introduced as the generalization of the density functional. The one‐loop approximation offers an iterative, perturbative solution of the Hartree–Fock equations by turning on the Coulomb interaction gradually. A renormalization group evolution equation for the density‐dependent effective action is proposed, enabling one to systematically improve the description of the nonrelativistic electron system beyond the one‐loop level. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
Recent progress in constructing nonlocal energy density functionals
Authors: March N. H. , Howard I. A. , Van Doren V. E. 
Published: February 2003

AbstractBoth model results and some exact relations concerning kinetic, exchange, and correlation energy density functionals will be presented. As to single‐particle kinetic energy, a model of harmonic confinement, motivated by recent experimental activity on Fermion vapors, of an arbitrary number of Fermions will be used to construct exact nonlocal kinetic energy density functionals in both one and three dimensions. Then, some further exact results concerning nuclear cusp conditions for exchange only, and for exchange plus correlation, will be discussed. Finally, in Appendices, the one‐shell harmonic confinement is generalized to include Coulomb repulsion in the two‐electron Hookean atom and some results on the Pauli potentials for many‐Fermion systems are obtained. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
Sinc wave packets: New form of wave packet for time‐dependent quantum mechanical reactive scattering calculations
Authors: Hankel Marlies , Balint‐Kurti Gabriel G. , Gray Stephen K. 
Published: February 2003

AbstractA new form of wave packet, the sinc wave packet, is defined. The wave packet has some advantages for use in time‐dependent quantum mechanical reactive scattering calculations. These advantages consist of the fact that it possesses a reasonable constant amplitude over a range of momenta or energies. Quantum mechanical calculations undertaken using such a wave packet will therefore result in a more even‐handed treatment of all the energies within the range of energies treated by the calculation. Test calculations demonstrate that the new sinc wave packets always yield slightly more accurate results than equivalent Gaussian wave packets. They are also easier to use because the range of energies they effectively cover may be more easily assessed. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
Hydrogenic orbitals in momentum space and hyperspherical harmonics: Elliptic Sturmian basis sets
Authors: Aquilanti Vincenzo , Caligiana Andrea , Cavalli Simonetta , Coletti Cecilia 
Published: February 2003

AbstractMomentum space hydrogenic orbitals can be regarded as orthonormal and complete Sturmian basis sets and explicitly given in terms of (hyper)‐spherical harmonics on the 4‐D hypersphere S3. Among the alternative coordinate systems that allow separation of variables, the usual ones involving parameterizations of the sphere S3 by circular functions correspond to canonical subgroup reduction chains; we also investigate harmonic “elliptic” sets (as, e.g., obtained by parameterizations in terms of Jacobi elliptic functions). In this article we list the canonical hydrogenic Sturmian sets and the orthogonal transformations connecting them. The latter enjoy useful three‐term recurrence relationships that allow their efficient calculations even for large strings. We also consider modifications needed when the conservation of the symmetry of Sturmians with respect to parity. Finally, we discuss some properties of elliptic hydrogenic Sturmians and their relations with canonical Sturmians. Because elliptic Sturmians cannot be expressed in closed form, it is important to find expansions in a suitable basis set and calculate the transformation coefficients. We derive three‐term recursion relationships fulfilled by the coefficients of the transformation between elliptic Sturmians and canonical Sturmians. A concluding discussion on the connections between configuration space and momentum space hydrogenic Sturmians completes this article. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
Exact expressions for energy functional in the time‐dependent density functional theory
Authors: Nagy Á. 
Published: February 2003

AbstractExact equations for correlation energy and kinetic energy correction functionals are derived in the time‐dependent density functional theory. Hierarchies of equations are also obtained and approximate functionals are proposed by truncation of the hierarchies at different orders. Explicit relations for the correlation energy and its kinetic component along the adiabatic path are given in terms of powers of the moments of the electron density. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
Study of subspace density functional theory application of LSDA to excited states of atoms
Authors: Tasnádi F. , Nagy Á. 
Published: February 2003

AbstractApplicability of the subspace density functional theory (SDFT) for calculation of excitation energies of atoms is studied. In the SDFT the subspace construction gives the opportunity to perform calculations with the standard ground‐state potentials or make a distinction between the subspaces with different quantum numbers (L and S), using special potentials depending on the quantum numbers. Theophiliou and Papaconstantinou gave a spin‐indexed version of the local von Barth–Hedin potential to treat singlet and triplet states. In this article we study the same spin‐indexed potential for atoms having multiplet structure and compare the results with the values obtained in calculations using the ground‐state version of the von Barth–Hedin potential. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
Vibrational analysis of various isotopomers of L‐Alanyl‐L‐Alanine in aqueous solution: Vibrational absorption, vibrational circular dichroism, Raman, and Raman optical activity spectra
Authors: Jalkanen K. J. , Nieminen R. M. , Knapp‐Mohammady M. , Suhai S. 
Published: February 2003

AbstractIn a recent work (Knapp‐Mohammady, M.; Jalkanen, K. J.; Nardi, F.; Wade, R. C.; Suhai, S. Chem Phys 1999, 240, 63–77) the structures of the zwitterionic species of L‐alanyl‐L‐alanine (LALA) in aqueous solution using a combination of molecular mechanics (MM) and density functional theory (DFT) have been reported. Subsequently, the vibrational absorption (VA) and vibrational circular dichroism (VCD) and the Raman and Raman Optical Activity (ROA) spectra have been reported. In this work an analysis of the aqueous solution VA, VCD, Raman, and ROA spectra for various isotopomers of LALA are reported. DFT Becke3LYP/6‐31G* theory has been used to determine the geometry, Hessian, atomic polar tensors (APT), and atomic axial tensors (AAT), and the electric dipole–electric dipole polarizability derivatives (EDEDPD), which are required for us to simulate the VA, VCD, and Raman spectra. The electric dipole–magnetic dipole polarizability derivatives (EDMDPD) and the electric dipole–electric quadrapole polarizability derivatives (EDEQPD) have been calculated at the RHF/6‐31G* level of theory. The VA, VCD, Raman, and ROA spectral simulations for the various isotopomers are compared with the experimentally measured spectra. With the DFT, explicit water molecules, and a continuum solvent model we are better able to reproduce the vibrational absorption and Raman spectra than previously reported. The AAT have been implemented at the DFT level, although not within the continuum treatment. The VCD sign pattern could be reproduced with the DFT atomic axial tensors calculated for the LALA plus explicit water molecules. The continuum treatment of the solvent for the calculation of these tensors appears to be a secondary effect. The ROA spectra are not well reproduced due to the failure to take into account electron correlation via DFT and the continuum treatment of the solvent for the EDMDPD and EDEQPD. We look forward to reporting ROA simulations utilizing more accurate tensors in the near future. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
Design of a new mechanism for context data storage on Web systems and its implementation using component‐object technology
Authors: Uehara Satoru , Mizuno Osamu , Kikuno Tohru 
Published: February 2003

AbstractIn this research, the authors design and implement a new mechanism to store shared data (context data) across several sessions in a World Wide Web (hereafter Web) system. The Web is being used more and more in client–server system architecture, and this trend is continuing. However, in a client–server system that uses a Web system, problems that did not occur on conventional client–server systems (those that do not use the Web) occur. One of these is storing context data. The HTTP (HyperText Transfer Protocol) protocol used in a Web system is a session, and as a result context data cannot be preserved. Although several mechanisms to store the context data have been proposed, each has problems with security and reliability. The authors have decided to use the so‐called document view architecture in order to design a new context data storage mechanism to resolve these problems. This architecture provides the primary functions needed to store context data. The special characteristic of this new mechanism is found in storing context data in main memory on the client computer. In addition, the authors decided to introduce component‐object technology to improve efficiency. This allows for a significant increase in security and reliability. Finally, the authors demonstrate the validity of their new context data storage mechanism using common applications. © 2003 Wiley Periodicals, Inc. Syst Comp Jpn, 34(3): 53–63, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10020
Development of a user adaptive home page recommendation software, “WebNavigator”
Authors: Kutsumi Hiroshi , Naito Eiichi , Araki Shoichi , Emura Satoshi , Arai Tadaharu 
Published: February 2003

AbstractThe authors report on the development of their software “WebNavigator,” a tool for gathering home page information easily for new Internet users, which learns the preferences of the user based on home page viewing history and then recommends new home pages based on those preferences. The important factors in learning a user's preferences are immediacy for tracking changes in interests and stability so as not to be affected by the noise included in the observed data. Issues for the software include setting parameters to unify the earlier user profile and the feature vector for home pages being viewed at present. These rate parameters are found by learning, using several home pages deemed to be “interesting” or “not interesting” to the user. The changes in the user's interests can be tracked by observing the changes in these parameters over time. In this paper, the authors describe the results of evaluating the validity of the software's home page recommendations by investigating experimentally the changes in various users' interests. © 2003 Wiley Periodicals, Inc. Syst Comp Jpn, 34(3): 44–52, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10069
Morphological operations by locally variable structuring elements and their applications to region extraction in ultrasound images
Authors: Ito Masayasu , Tsubai Masayoshi , Nomura Akira 
Published: February 2003

AbstractIn this paper, we define a new adaptive morphological operation, in which the value of a structuring element varies adaptively depending on the local intensity information of the processing image of interest. We prove that the proposed adaptive morphological operation has almost the same mathematical structure and properties as the conventional ones have. There are many useful functions in the method. Among them are the opening and closing, which implement both smoothing of the image and emphasizing of the edges at a time. Conventional opening operation has a smoothing function but not both. Applying our method to relatively unclear images such as ultrasound ones with speckle noise, its usefulness can be found in extracting regions. We also discuss parameter setting, and its enhancement effect together with experimental results is demonstrated. © 2003 Wiley Periodicals, Inc. Syst Comp Jpn, 34(3): 33–43, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10196
A method for arrangement of road network based on streetwise transformation
Authors: Yamamori Kazunori , Honda Hiroshi , Hasegawa Junichi 
Published: February 2003

AbstractThis paper considers the simplified map (deformé map) for road guide, which is often used in advertisements and pamphlets, and proposes a new road rearrangement method. For this type of road deformation problem, the authors have already developed a parallel and iterative method of straightening transformation and the direction quantization of the road segment (edge). With the past method, however, it is not always true that the globally satisfactory rearrangement is obtained, because of the edgewise applied transformation. From such a viewpoint, this paper proposes a new parallel transformation method using the street, not the edge, as the unit. In this paper, a “street” refers to a sequence of edges that continue almost as a straight line. As the first step herein, all streets are automatically extracted from the input road map. Then, streets are divided into several classes based on their directions and shape features. Lastly, the edge composing the street is transformed by the force determined for each class. In the experiment using 88 actual road maps, the proposed method produced better results than the past method for 95% of the whole maps. © 2003 Wiley Periodicals, Inc. Syst Comp Jpn, 34(3): 20–32, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10202
A real‐time vision‐based interface using Motion Processor and applications to robotics
Authors: Mihara Isao , Yamauchi Yasunobu , Doi Miwako 
Published: February 2003

AbstractThe authors developed a new vision‐based interface that detects gestures in real time to enable interaction between the user and computer. This vision‐based interface consists of two elements: the “Motion Processor™” and the “extraction of the region of interest (ROI).” The Motion Processor is a new image acquisition device. By illuminating the target object with near‐infrared light and using image sensors to collect the reflected light, the Motion Processor can eliminate the background and collect shape, motion, and depth information of only the target object. In addition, the authors proposed a method of using the collected image depth information to quickly and stably extract the ROI and showed, according to evaluation experiments on a PC, that the region can be detected with high precision within 0.06 second. Real‐time sensing of the shape and motion of a specific object from an image can be implemented by using the Motion Processor and this ROI extraction method, enabling this interface to function as a computer eye that can easily recognize a target object. The authors applied this real‐time vision‐based interface to the field of robotics and used it together with speech recognition on a single PC to create a prototype of a pet robot system that can respond to the user's gestures. © 2003 Wiley Periodicals, Inc. Syst Comp Jpn, 34(3): 10–19, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10203
A local indexing for learning resources on WWW
Authors: Hasegawa Shinobu , Kashihara Akihiro , Toyoda Jun'ichi 
Published: February 2003

AbstractLearning with existing Web‐based resources has become popular and important, particularly as the realization of lifelong and distance learning. However, many resources do not usually have a clear description of what kind of learners should use them, what kind of learning goal can be achieved, and so forth, which makes it difficult for learners to select appropriate Web‐based resources. We have accordingly proposed a framework for reorganizing existing Web‐based learning resources with indexes representing their characteristics, which consist of “How To Learn” indexes in addition to conventional “What To Learn” indexes, in order to build a learning resource database. This framework supports a new approach called local indexing, which allows instructors to assess indexes of the resources from their own points of view. This paper also describes a support for the local indexing and its preliminary evaluation. The results of this evaluation suggest that the local indexing support enables instructors to simply and consistently find out how learning resources should be learned. © 2003 Wiley Periodicals, Inc. Syst Comp Jpn, 34(3): 1–9, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10231
Video stream selection according to lecture content in remote lectures
Authors: Sakiyama Takuro , Ohno Naoki , Mukunoki Masayuki , Ikeda Katsuo 
Published: February 2003

AbstractIn a remote lecture photographed by multiple cameras, the task of selecting the video streams to be transmitted to a remote location is now performed mainly by the lecturer, and represents a large burden. This paper proposes a method for automating this task. The lecture context is expressed as a predefined sequence of transitions between lecture states, and the relationship between the lecture context and the video streams to be transmitted is implemented as rules. Since the lecture states are constructed as combinations of easily observable information from real lecture scenes, the appropriate video streams can be selected without an understanding of lecture content by matching the extracted lecture state sequences against the predefined rules. Experiments with simulated lectures using a blackboard and overhead projector have shown that the proposed method is effective in real‐time selection of the video streams to be transmitted. © 2003 Wiley Periodicals, Inc. Syst Comp Jpn, 34(3): 64–75, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.1195