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Academic literature on the topic 'Quantum theory of atoms in molecules'

Author: Grafiati

Published: 4 June 2021

Last updated: 9 March 2023

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Journal articles on the topic "Quantum theory of atoms in molecules"

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Orville-Thomas, W. J. "Atoms in Molecules — a Quantum Theory." Journal of Molecular Structure: THEOCHEM 360, no. 1-3 (January 1996): 175. http://dx.doi.org/10.1016/s0166-1280(96)90925-2.

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Potemkin, Vladimir, Nadezhda Palko, and Maria Grishina. "Quantum theory of atoms in molecules for photovoltaics." Solar Energy 190 (September 2019): 475–87. http://dx.doi.org/10.1016/j.solener.2019.08.048.

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Wzgarda-Raj, Kinga, Agnieszka J. Rybarczyk-Pirek, Sławomir Wojtulewski, and Marcin Palusiak. "C—Br...S halogen bonds in novel thiourea N-oxide cocrystals: analysis of energetic and QTAIM parameters." Acta Crystallographica Section C Structural Chemistry 76, no. 2 (January 29, 2020): 170–76. http://dx.doi.org/10.1107/s2053229620000947.

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Cocrystals of thiourea with 4-nitropyridine N-oxide, C5H4N2O3·2CH4N2S, (I), and 3-bromopyridine N-oxide, C5H4BrNO·CH4N2S, (II), crystallize in the monoclinic space group P21/c. In the crystals, molecules of both components are linked by N—H...O hydrogen bonds, creating R 2 1(6) synthons. The bromine substituent of the N-oxide component in (II) is a centre for C—Br...S halogen bonding to the thiourea molecule. Computations based on quantum chemistry methods (quantum theory of atoms in molecules, QTAIM) and atoms in molecules (AIM) theory were performed for a more detailed description of the observed type of halogen-bonding interaction.

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DELLE SITE, L. "ON THE RELEVANCE OF THE WAVEFUNCTION'S PHASE FACTOR FOR UNDERSTANDING TOPOLOGICAL PROPERTIES OF ATOMS AND MOLECULES IN CONDENSED PHASES: A SIMPLE EXAMPLE." International Journal of Modern Physics B 15, no. 04 (February 10, 2001): 403–8. http://dx.doi.org/10.1142/s0217979201004502.

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In preceding work1,2 we proposed a criterion for defining atoms in molecules and in condensed phases based on the determination of the zero flux surface of the quantum current vector which holds the zero flux condition at every point. Here such a surface is calculated analytically in the simple case of a general hydrogen-like wavefunction with a non-constant phase factor. This simple example is then used as a basis to build an easy picture of the basic topological properties of atoms (or molecules) in multiatomic systems; these properties are particularly relevant for a molecular modeling procedure and a subsequent implementation in a simulation scheme. The main goal of this work is to underline with a simple example the importance of the wavefunction's phase factor in defining atoms or molecules in condensed systems (as it has been emphasized in our previous work); this point is important since a largely used theory (for defining atoms and molecules in condensed phases) such as the Bader's theory of atoms in molecules3 systematically neglects the properties of the wavefunction's phase factor.

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Krawczuk, Anna, Daniel Pérez, and Piero Macchi. "PolaBer: a program to calculate and visualize distributed atomic polarizabilities based on electron density partitioning." Journal of Applied Crystallography 47, no. 4 (June 14, 2014): 1452–58. http://dx.doi.org/10.1107/s1600576714010838.

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This paper describes the program PolaBer, which calculates atomic polarizability tensors from electric field perturbations of a partitioned electron density distribution. Among many possible partitioning schemes, PolaBer is currently using the quantum theory of atoms in molecules and it is interfaced to programs that apply such a partitioning. The calculation of the atomic tensors follows the idea suggested by Keith [The Quantum Theory of Atoms in Molecules: From Solid State to DNA and Drug Design, (2007), edited by C. F. Matta & R. J. Boyd. Weinheim: Wiley-VCH], which enables the removal of the intrinsic origin dependence of the atomic charge contributions to the molecular dipole moment. This scheme allows the export, within chemically equivalent functional groups, of properties calculated from atomic dipoles, such as for example the atomic polarizabilities. The software permits visualization of the tensors and calculation of straightforward optical properties of a molecule (like the molar refractive index) or a crystal (assuming the molecule in a given crystal lattice).

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Foroutan-Nejad, Cina, Gholam Hossein Shafiee, Abdolreza Sadjadi, and Shant Shahbazian. "Ab initio charge density analysis of (B6C)2 and B4C3 species How to describe the bonding pattern?" Canadian Journal of Chemistry 84, no. 5 (May 1, 2006): 771–81. http://dx.doi.org/10.1139/v06-059.

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In this study, a detailed topological charge density analysis based on the quantum theory of atoms in molecules (QTAIM) developed by Bader and co-workers, has been accomplished (using the B3LYP method) on the CB62 anion and three planar isomers of the C3B4 species, which had been first proposed by Exner and Schleyer as examples of molecules containing hexacoordinate carbon atoms. The analysis uncovers the strong (covalent) interactions of boron atoms as well as the "nondirectional" interaction of central carbon atom with those peripheral atoms. On the other hand, instabilities have been found in the topological networks of (B6C)2 and B4C3(para) species. A detailed investigation of these instabilities demonstrates that the topology of charge density has a floppy nature near the equilibrium geometries of the species under study. Thus, these species seems to be best described as complexes of a relatively concrete ring containing boron or carbon atoms and a central carbon atom that is confined in the plane of the molecule, but with nondirectional interactions with the surrounding atoms.Key words: hypervalency, hexacoordinate carbon, quantum theory of atoms in molecules, charge density analysis, ab initio methods.

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McWeeny, Roy. "The Quantum Mechanics of Cohesion." Collection of Czechoslovak Chemical Communications 72, no. 2 (2007): 252–68. http://dx.doi.org/10.1135/cccc20070252.

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We consider the fundamental problem of "what makes atoms stick together in molecules, crystals, or clusters?" The Heitler and London paper (1927) on the hydrogen molecule marked a first attempt to discuss, in terms of quantum mechanics, the interaction of two atoms with unpaired spins. The aim of this note is to show how the primitive concepts used eighty years ago still retain a certain validity even in a much more general context. We consider in fact the interaction of two arbitrary systems, each with a resultant spin angular momentum, and show how the interaction energy depends on the scalar product of the two resultants. The actual nature of the two systems is irrelevant: they may be atoms, molecules, or ionic species of any kind each described by a wave function which may be, in principle, exact. This provides a first step in the formulation of any general theory of cohesion.

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TARASOV, VASILY E. "QUANTUM NANOTECHNOLOGY." International Journal of Nanoscience 08, no. 04n05 (August 2009): 337–44. http://dx.doi.org/10.1142/s0219581x09005517.

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Nanotechnology is based on manipulations of individual atoms and molecules to build complex atomic structures. Quantum nanotechnology is a broad concept that deals with a manipulation of individual quantum states of atoms and molecules. Quantum nanotechnology differs from nanotechnology as a quantum computer differs from a classical molecular computer. The nanotechnology deals with a manipulation of quantum states in bulk rather than individually. In this paper, we define the main notions of quantum nanotechnology. Quantum analogs of assemblers, replicators and self-reproducing machines are discussed. We prove the possibility of realizing these analogs. A self-cloning (self-reproducing) quantum machine is a quantum machine which can make a copy of itself. The impossibility of ideally cloning an unknown quantum state is one of the basic rules of quantum theory. We prove that quantum machines cannot be self-cloning if they are Hamiltonian. There exist quantum non-Hamiltonian machines that are self-cloning machines. Quantum nanotechnology allows us to build quantum nanomachines. These nanomachines are not only small machines of nanosize. Quantum nanomachines should use new (quantum) principles of work.

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Grant, IP. "Current Developments in the Relativistic Quantum Mechanics of Atoms and Molecules." Australian Journal of Physics 39, no. 5 (1986): 649. http://dx.doi.org/10.1071/ph860649.

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Current work in relativistic quantum mechanics by the author and his associates focusses on four topics: atomic structure theory using the GRASP package (Dyall 1986); extension of GRASP to handle electron continuum processes; the relation of quantum electrodynamics and relativistic quantum mechanics of atoms and molecules; and development of methods using finite basis set expansions for studying electronic structure of atoms and molecules. This paper covers only the last three topics, giving emphasis to growing points and outstanding difficulties.

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Kawamura, Kiyoshi, and Mikio Eto. "Theory of Artificial Atoms and Molecules using Semiconductor Quantum Dots." Japanese Journal of Applied Physics 38, Part 1, No. 1B (January 30, 1999): 366–71. http://dx.doi.org/10.1143/jjap.38.366.

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Dissertations / Theses on the topic "Quantum theory of atoms in molecules"

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Skaane, Haakon. "Relativistic quantum theory and its applications to atoms and molecules." Thesis, University of Oxford, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267921.

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Xu, Gang. "Manipulation and quantum control of ultracold atoms and molecules for precision measurements." Access restricted to users with UT Austin EID, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3038196.

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Baskerville, Adam. "The quantum chemical physics of few-particle atoms and molecules." Thesis, University of Sussex, 2018. http://sro.sussex.ac.uk/id/eprint/77136/.

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The many-electron Schrödinger equation for atoms and molecules still remains analytically insoluble after over 90 years of investigation. This has not deterred scientists from developing a large variety of elegant techniques and approximations to workaround this issue and make many-particle quantum calculations computationally tractable. This thesis presents an all-particle treatment of three-particle systems which represent the simplest, most complex, many-particle systems including electron correlation and nuclear motion effects; meaning they provide a close-up view of fundamental particle interaction. Fully-Correlated (FC) energies and wavefunctions are calculated to high accuracy (mJ mol−1 or better for energies); and the central theme of this work is to use the wavefunctions to study fundamental quantum chemical physics. Nuclear motion has not received the same attention as electronic structure theory and this complicated coupling of electron and nuclear motions is studied in this work with the use of intracule and centre of mass particle densities where it is found nuclear motion exhibits strong correlation. A highly accurate Hartree-Fock implementation is presented which uses a Laguerre polynomial basis set. This method is used to accurately calculate electron correlation energies using the Löwdin definition and Coulomb holes by comparing with our FC data. Additionally the critical nuclear charge to bind two electrons within the HF methodology is calculated. A modification to Pekeris' series solution method is implemented to accurately model excited states of three-particle systems, and adapted to include the effects of nuclear motion along with three Non-Linear variational Parameters (NLPs) to aid convergence. This implementation is shown to produce high accuracy results for singlet and triplet atomic excited S states and the critical nuclear charge to bind two electrons in both spin states is investigated. Geometrical properties of three-particle systems are studied using a variety of particle densities and by determining the bound state stability at the lowest continuum threshold as a function of mass. This enables us to better ascertain what is meant when we define a system as an atom or a molecule.

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Li, Ming. "Quantum Theory of Ion-Atom Interactions." University of Toledo / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1404667900.

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Engdahl, Erik. "Computation of resonance energies and spectral densities in the complex energy plane : application of complex scaling techniques for atoms, molecules and surfaces /." Uppsala : Uppsala Universitet, 1988. http://bibpurl.oclc.org/web/32938.

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Sharkey, Keeper Layne. "Very Accurate Quantum Mechanical Non-Relativistic Spectra Calculations of Small Atoms & Molecules Employing All-Particle Explicitly Correlated Gaussian Basis Functions." Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/560835.

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Due to the fast increasing capabilities of modern computers it is now feasible to calculate spectra of small atom and molecules with the greater level of accuracy than high-resolution measurements. The mathematical algorithms developed and implemented on high performance supercomputers for the quantum mechanical calculations are directly derived from the first principles of quantum mechanics. The codes developed are primarily used to verify, refine, and predict the energies associated within a given system and given angular momentum state of interest. The Hamiltonian operator used to determine the total energy in the approach presented is called the internal Hamiltonian and is obtained by rigorously separating out the center-of-mass motion (or the elimination of translational motion) from the laboratory-frame Hamiltonian. The methods utilized in the articles presented in this dissertation do not include relativistic corrections and quantum electrodynamic effects, nor do these articles assume the Born-Oppenheimer (BO) approximation with the exception of one publication. There is one major review article included herein which describes the major differences between the non-BO method and the BO approximation using explicitly correlated Gaussian (ECG) basis functions. The physical systems studied in this dissertation are the atomic elements with Z < 7 (although the discussion is not limited to these) and diatomic molecules such as H₂⁺ and H₂ including nuclear isotopic substitution studies with deuterium and tritium, as well as electronic substitutions with the muon particle. Preliminary testing for triatomic molecular functionals using a model potential is also included in this dissertation. It has been concluded that using all-particle ECGs with including the addition of nonzero angular momentum functions to describe nonzero angular momentum states is sufficient in determining the energies of these states for both the atomic and molecular case.

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Orlando, A. M. "NEW INSIGHT IN ELECTRON DENSITY AND ELECTRON SPIN DENSITY THROUGH TOPOLOGICAL DESCRIPTORS BASED ON BADER'S THEORY OF ATOM IN MOLECULES." Doctoral thesis, Università degli Studi di Milano, 2016. http://hdl.handle.net/2434/374929.

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This Ph.D. thesis is focused on the application of quantum theory of atoms in molecules (QTAIM) based chemical descriptors to challenging chemical test-cases, as well as on the development of novel topological descriptors, like the Source Function for the spin density. The thesis is organized as follows: In chapter 1 the electron density (ED) of a very unusual structural feature in a synthetic beta–sultamic analogue (DTC), has been explored by both low-T single–crystal X–ray diffraction and quantum mechanical simulations to gain insights into the subtle interplay between structure, electron delocalization and crystal field polarization effects. The core chemical moiety in DTC is an uncommon 4–membered thiazete–1,1–dioxide heterocycle, where the formally single N–C bond is, on average, 0.018 Å shorter than the formally double N=C bond. Both local and non–local topological descriptors provided by QTAIM have been employed in the analysis of DTC in comparison with chemically related derivatives and possible implications from the viewpoint of the accurate in silico modelling of crystal structures are discussed. Particular attention is dedicated on such kind of issues in chemical and pharmaceutical industries, because the control of the crystal structure is really problematic in some cases; in fact different polymorphs of the same substance have different intensive physical properties, such as solubility, refraction index and conductivity and problems may arise in industrial processes related to the synthesis of chemicals and drugs on large scale. In chapter 2, we focused on the source function (SF) QTAIM based topological descriptor. The electron density (ED) at any point r within a system may be regarded as consisting of a sum of SF contributions S(r; X) representing a measure of how the various atomic basins (X) or groups of atomic basins defined through QTAIM contribute to determine the ρ(r) at r. Recently it was shown that the SF is able to reveal electron delocalization effects in planar electron conjugated systems, in terms of an increased capability of determining the ED along a given bond by the distant, though through-bonds connected, atomic basins and, at the same time, into a decreased ability to do so by the two atoms directly involved in the bond. Such an adjustment of sources then translates into a pictorial pattern of enhanced and reduced atomic SF contributions from, respectively, distant and nearby atoms, compared to the case of a partially or fully saturated network of bonds. Then we have extended such an analysis to the non planar conjugated systems, where the usual electron separation does no longer apply. Being based on the total ED, the SF analysis may be safely applied also in these less conventional electron delocalized systems. In the present Ph. D. thesis we have extended the SF reconstruction approach also to the electron density spin counterparts in vacuo. Such reconstruction was investigated both on simple (but chemically meaningful) spin-polarized molecular systems and on more complex single-molecule magnets. This investigation has showed that the difference between the two spin counterparts of electron density distribution can be reconstructed with a sufficient accuracy, analogously to the case of the total ED. Moreover, it was found that the SF for the electron spin density brings in precious chemical information, neatly distinguishing the quite different roles played by the unpaired electrons ED and the spin polarized ED due to the remaining electrons. Furthermore, quantitative answers to questions related to the transferability of the spin density in alkyl radicals or to the transmission of spin information in metal(s)-ligand systems were provided. Understanding, from a real space perspective, by which mechanisms spin information transmits, might be of relevance to interpret the fundamental magnetic interactions present in complex materials, such as for example coordination polymers or Heussler and half-Heussler alloys. As these interactions have a key role in spintronics, characterization of the chemical bond and interpretation of the electron spin density distributions in these systems through the SF analysis, could hopefully disclose structure-property relationships extremely useful for the design of materials with particular physical properties.

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Hey, Jakob. "From X-ray diffraction data annealing to comprehensive charge density analysis." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2013. http://hdl.handle.net/11858/00-1735-0000-0001-BBE1-7.

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Fournet, Steven P. "High Resolution X-ray Diffraction Analysis of CB1 Receptor Antagonists as a Means to Explore Binding Affinity." ScholarWorks@UNO, 2013. http://scholarworks.uno.edu/td/1737.

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Abstract Charge density studies have been conducted on ten CB1 cannabinoid receptor antagonists via high resolution x-ray crystallography. Bond critical point values and various other properties derived from these studies including the electrostatic potential were analyzed in correlation to the affinity of each compound with the CB1 receptor. Correlation/anti-correlation was found between several properties and Ki. The data was also interpreted by principal component analysis with three principal components accounting for 85% of the data variation. Data mining was limit due to the low sample count and the requirements set for the inclusion of correlated/anti-correlated variables left fewer variables to analyze. The model presented is left for future interpretation.

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Rossi, François-Noël. "Etude théorique des collisions non réactives entre atomes alcalins et molécules d'hydrogène ou de deuterium : Calcul et analyse des surfaces de potentiel, application aux transitions de structure fine du rubidium." Paris 13, 1986. http://www.theses.fr/1986PA132015.

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Calcul des courbes de potentiel adiabatiques pour les géométries colinéaires et perpendiculaires, à l'aide d'un pseudopotentiel dépendant du moment orbital électronique et d'une approche à deux centres; bon accord avec les calculs ab initio existants. Examen des différentes symétries de ces systèmes dans le formalisme de la théorie des groupes, afin d'étudier les valeurs propres et facteurs propres de l'hamiltonien électronique. Calcul quantique des sections efficaces relatives des transitions de structure fine de Rb induites par collision avec H(2) ou D(2). En tenant compte des niveaux rotationnels moléculaires, obtention d'un très bon accord avec les résultats expérimentaux et interprétation de l'effet isotopique

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Books on the topic "Quantum theory of atoms in molecules"

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Atoms in molecules: A quantum theory. Oxford: Clarendon Press, 1990.

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Bader, Richard F. W. Atoms in molecules: A quantum theory. Oxford [England]: Clarendon Press, 1994.

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Grant, I. P., ed. Relativistic Quantum Theory of Atoms and Molecules. New York, NY: Springer New York, 2007. http://dx.doi.org/10.1007/978-0-387-35069-1.

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4

Relativistic quantum theory of atoms and molecules: Theory and computation. New York: Springer, 2007.

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March, Norman H. Electron density theory of atoms and molecules. London: Academic Press, 1992.

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1923-, Resnick Robert, ed. Quantum physics of atoms, molecules, solids, nuclei, and particles. 2nd ed. New York: Wiley, 1985.

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Weitao, Yang, ed. Density-functional theory of atoms and molecules. New York: Oxford University Press, 1989.

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Quantum mathematical physics: Atoms, molecules and large systems. 2nd ed. Berlin: Springer, 2002.

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Bjarne, Amstrup, ed. Introduction to the quantum world of atoms and molecules. Singapore: World Scientific, 2001.

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Introduction to the quantum world of atoms and molecules. Singapore: World Scientific, 2001.

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Book chapters on the topic "Quantum theory of atoms in molecules"

1

Hertel, Peter. "Atoms and Molecules." In Quantum Theory and Statistical Thermodynamics, 65–110. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-58595-6_3.

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Avery, John. "Dimensional Scaling in Quantum Theory." In Structure and Dynamics of Atoms and Molecules: Conceptual Trends, 133–54. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-011-0263-6_5.

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Lieb, Elliott H. "Some Fundamental Properties of the Ground States of Atoms and Molecules." In Fundamental Aspects of Quantum Theory, 209–14. Boston, MA: Springer US, 1986. http://dx.doi.org/10.1007/978-1-4684-5221-1_23.

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Lombardi, Olimpia, and Chérif F. Matta. "Coarse Graining and the Quantum Theory of Atoms in Molecules." In Philosophical Perspectives in Quantum Chemistry, 217–41. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-98373-4_10.

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Garza, Jorge, and Rubicelia Vargas. "Density Functional Theory Applied on Confined Many-Electron Atoms." In Electronic Structure of Quantum Confined Atoms and Molecules, 205–25. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-09982-8_8.

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Cioslowski, Jerzy, and Jacek Karwowski. "Quantum-Mechanical Theory of Atoms in Molecules: A Relativistic Formulation." In Mathematical and Computational Chemistry, 101–12. Boston, MA: Springer US, 2001. http://dx.doi.org/10.1007/978-1-4757-3273-3_7.

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Weeks, John D., Andrew Hazi, and Stuart A. Rice. "On the Use of Pseudopotentials in the Quantum Theory of Atoms and Molecules." In Advances in Chemical Physics, 283–342. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2007. http://dx.doi.org/10.1002/9780470143612.ch6.

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Schöllkopf, Wieland. "Grating Diffraction of Molecular Beams: Present Day Implementations of Otto Stern’s Concept." In Molecular Beams in Physics and Chemistry, 575–93. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-63963-1_25.

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AbstractWhen Otto Stern embarked on molecular-beam experiments in his new lab at Hamburg University a century ago, one of his interests was to demonstrate the wave-nature of atoms and molecules that had been predicted shortly before by Louis de Broglie. As the effects of diffraction and interference provide conclusive evidence for wave-type behavior, Otto Stern and his coworkers conceived two matter-wave diffraction experiments employing their innovative molecular-beam method. The first concept assumed the molecular ray to coherently scatter off a plane ruled grating at grazing incidence conditions, while the second one was based on the coherent scattering from a cleaved crystal surface. The latter concept allowed Stern and his associates to demonstrate the wave behavior of atoms and molecules and to validate de Broglie’s formula. The former experiment, however, fell short of providing evidence for diffraction of matter waves. It was not until 2007 that the grating diffraction experiment was retried with a modern molecular-beam apparatus. Fully resolved matter-wave diffraction patterns were observed, confirming the viability of Otto Stern’s experimental concept. The correct explanation of the experiment accounts for quantum reflection, another wave effect incompatible with the particle picture, which was not foreseen by Stern and his contemporaries.

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Werstiuk, N. H., K. E. Laidig, and J. Ma. "Application of Quantum Theory of Atoms in Molecules to Study of Anomeric Effect in Dimethoxymethane." In ACS Symposium Series, 176–204. Washington, DC: American Chemical Society, 1993. http://dx.doi.org/10.1021/bk-1993-0539.ch010.

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Keil, Mark, Shimon Machluf, Yair Margalit, Zhifan Zhou, Omer Amit, Or Dobkowski, Yonathan Japha, et al. "Stern-Gerlach Interferometry with the Atom Chip." In Molecular Beams in Physics and Chemistry, 263–301. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-63963-1_14.

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AbstractIn this invited review in honor of 100 years since the Stern-Gerlach (SG) experiments, we describe a decade of SG interferometry on the atom chip. The SG effect has been a paradigm of quantum mechanics throughout the last century, but there has been surprisingly little evidence that the original scheme, with freely propagating atoms exposed to gradients from macroscopic magnets, is a fully coherent quantum process. Specifically, no full-loop SG interferometer (SGI) has been realized with the scheme as envisioned decades ago. Furthermore, several theoretical studies have explained why it is a formidable challenge. Here we provide a review of our SG experiments over the last decade. We describe several novel configurations such as that giving rise to the first SG spatial interference fringes, and the first full-loop SGI realization. These devices are based on highly accurate magnetic fields, originating from an atom chip, that ensure coherent operation within strict constraints described by previous theoretical analyses. Achieving this high level of control over magnetic gradients is expected to facilitate technological applications such as probing of surfaces and currents, as well as metrology. Fundamental applications include the probing of the foundations of quantum theory, gravity, and the interface of quantum mechanics and gravity. We end with an outlook describing possible future experiments.

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Conference papers on the topic "Quantum theory of atoms in molecules"

1

Bandrauk, André D., and O. F. Kalman. "Dynamics in Intense Fields - Beyond the Dipole Approximation." In Multiple Excitations of Atoms. Washington, D.C.: Optica Publishing Group, 1986. http://dx.doi.org/10.1364/mea.1986.tuc1.

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We have recently shown in a series of papers [1-7] that coupled equations methods of quantum collision theory can be conveniently used to investigate processes such as direct photodissociation [1-2], Resonance Raman Scattering in weak and strong fields [3-5], and higher order nonlinear spectroscopies [6-7] for diatomics involving several well isolated excited electronic states. This was done using the dressed molecule picture [8-12] of molecule-radiation interaction, wherein photon states are explicitly included into the theoretical description. All these methods are adequate only in the case of well isolated electronic states. There is an urgent need to derive a priori the most efficient representation for general electron-nuclear-radiation field systems such as occurs in strong field laser chemistry. In recent work we have examined this problem in an effort to incorporate as much as possible the electromagnetic field into the dynamics [13-14]. One might surmise that classical approaches should work sufficiently well at the high field intensities described here, and much work has been pursued in that direction. As we have pointed out previously, this involves treating both the molecule and the field classically. For electron-radiation interactions one would prefer a quantum formulation, since electronic states are, as a result of their large excitation energies, true quantum states. Furthermore, quantum mechanics leads to a linear theory of interactions whereas classical mechanics is a highly nonlinear theory [15]. Thus using a quantum formulation of matter- field interactions [16-17], we have been able to exploit methods of early (non-covariant) quantum electrodynamics (QED). In particular we have shown that the Bloch-Nordsieck (BN) representation [18-20] (which leads naturally to the concept of coherent states in momentum space was very convenient as a method of introducing strong field effects directly into the quantum dynamics of molecular systems. Coulomb gauge ( A → . p → ) and Electric Field Gauge ( E → . r → ) representations were shown to be poor zeroth order approximations for the dressed molecular eigenstates in the presence of strong fields, i.e., the adiabatic coupled equations for the latter two gauges define the appropriate adiabatic state as unperturbed (zero field) molecular states [13-14].

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Krainov, V. P. "Barrier-Suppression Ionization of Complex Atoms and Diatomic Molecules." In Applications of High Field and Short Wavelength Sources. Washington, D.C.: Optica Publishing Group, 1997. http://dx.doi.org/10.1364/hfsw.1997.the8.

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Theory of tunneling ionization of atoms and atomic ions by strong low- frequency laser radiation was developed in Ref.[1] (so called ADK- approach). This theory is based on the conception of the quasi-stationary electromagnetoc field producing tunneling ejection of valence electrons. A complex atom or an atomic ion is considered in the frames of quantum defect method; its wave function is an asymptotic wave function at the large distances from the atomic core. In Ref.[2] the angular and energy distributions of ejected electrons in tunneling ionization were obtained.

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3

Zon, B. A. "Tunneling ionization of molecules." In Applications of High Field and Short Wavelength Sources. Washington, D.C.: Optica Publishing Group, 1997. http://dx.doi.org/10.1364/hfsw.1997.the10.

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The Ammosov–Delone–Krainov theory (ADK, [1]) is a wide-spread theory for describing the tunneling ionization of atoms in high light field. It is an important detail of this theory that the ionization probability is determined not only by the exponential factor, but also by the pre-exponential factor which depends upon the electron orbital momentum and magnetic quantum number.

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4

Soare, G. "A Physical Model of the Molecular-Quantum Natural Convection Heat Transfer Mechanism." In ASME 2003 Heat Transfer Summer Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/ht2003-47401.

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In this work a physical model of the natural convection heat transfer mechanism, molecular-quantum in nature, is proposed. On the surface of the solid there are a lot of chemical defects (atoms of different chemical elements) and geometrical ones (steps, kinks, terraces, dislocations) at microscopic and nanoscopic scale. All these defects make the surface of the wall to be not an equipotential surface. On the other hand, the existence of a gradient of temperature in a metal wall, which is involved in a heat transfer process, generates a gradient of conduction electrons. On the cool face of the wall there are more electrons as a result of Pe´ltier-Thomson effect. Because of surface’s defects the electrons are not uniformly distributed, on a high defect there are more electrons than on a depth defect and the electrical field is more intense on the high defect. The molecules of the fluid are adsorbed on the surface, and become polar molecules, as a result of the polarization by influence. The absorbed molecules form a multilayer in which take place more elementary processes, molecular-quantum in nature. These elementary processes are: the overlap between the electronic orbital of the solid and fluid, electron clouds perturbation, solid-fluid electron exchange by quantum tunneling effect, the motion under action of the Helmann-Feynman force between adsorbed molecules and a high defect of the wall, the absorption of the phonons from the surface’s atoms and rejection of the molecules from the surface. In this way natural convection is generated. The proposed model needs directly experimental confirmation.

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5

Domen, K., and T. J. Chuang. "Photofragmentation and Desorption of CH2I2 from Sapphire and Silver Surfaces by a UV Laser." In Microphysics of Surfaces, Beams, and Adsorbates. Washington, D.C.: Optica Publishing Group, 1987. http://dx.doi.org/10.1364/msba.1987.mb2.

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Lasers have been extensively used in recent years to induce gas-surface photochemistry. There exist, however, relatively few mechanistic studies on well characterized surfaces involving electronic excitation of adsorbed molecules. We have recently investigated the electronic excitation effect of CH2I2 molecules adsorbed on a sapphire crystal and silver surfaces with a XeCl laser. The molecule is chosen because it is readily activated by the 308 nm light pulses into its first and antibonding state. The excited molecules can dissociate into CH2I radicals and I atoms with a unit quantum yield in the gas phase.

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6

von Spakovsky, Michael R., Charles E. Smith, and Vittorio Verda. "Quantum Thermodynamics for the Modeling of Hydrogen Storage on a Carbon Nanotube." In ASME 2008 International Mechanical Engineering Congress and Exposition. ASMEDC, 2008. http://dx.doi.org/10.1115/imece2008-67424.

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A typical approach for modeling systems at a nanoscale in states of non-equilibrium undergoing an irreversible process is to use an ad hoc mixture of molecular dynamics (linear and nonlinear), i.e. classical mechanics, coupled to assumptions of stable equilibrium which allow one via analogy to incorporate equilibrium thermodynamic state information such as temperature and pressure into the modeling process. However, such an approach cannot describe the actual thermodynamic evolution in state which occurs in these systems since the equation of motion used (Newton’s second law) can only describe the evolution in state from one mechanical state to another. To capture the actual thermodynamic evolution, a more general equation of motion is needed. Such an equation has been proposed, i.e. the Beretta equation of motion, as part of a general theory, which unifies (not simply bridges as is the case in statistical thermodynamics) quantum mechanics and thermodynamics. It is called the unified quantum theory of mechanics and thermodynamics or quantum thermodynamics. This equation, which strictly satisfies all of the implications of the laws of thermodynamics, including the second law, as well as of quantum mechanics, describes the thermodynamic evolution in state of a system in non-equilibrium regardless of whether or not the system is in a state far from or close to stable equilibrium. This theory and its dynamical postulate are used here to model the storage of hydrogen in an isolated box modeled in 1D and 2D with a carbon atom at one end of the box in 1D and a carbon nanotube in the middle of the box in 2D. The system is prepared in a state with the hydrogen molecules initially far from stable equilibrium, after which the system is allowed to relax (evolve) to a state of stable equilibrium. The so-called energy eigenvalue problem is used to determine the energy eigenlevels and eigenstates of the system, while the nonlinear Beretta equation of motion is used to determine the evolution of the thermodynamic state of the system as well as the spatial distributions of the hydrogen molecules in time. The results of our initial simulations show in detail the trajectory of the state of the system as the hydrogen molecules, which are initially arranged to be far from the carbon atom or the carbon nanotube, are seen to spread out in the container and eventually become more concentrated near the carbon atom or atoms.

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7

Duarte, Leonardo José, and Roy Edward Bruns. "Infrared intensities of imaginary frequencies: Gas-Phase SN2 Transition States." In VIII Simpósio de Estrutura Eletrônica e Dinâmica Molecular. Universidade de Brasília, 2020. http://dx.doi.org/10.21826/viiiseedmol202032.

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The gas phase SN2 reaction transition state structures for nine [XCZ_3 Y]^- systems, where X,Y=H,F,Cl and Z = H,F were optimized and their normal modes of vibrations were determined at the QCISD/aug-cc-pVTZ level of theory. Using Quantum Theory of Atoms in Molecules (QTAIM), the atomic charges and atomic dipoles were obtained and used to calculate the Charge – Charge Transfer – Dipolar Polarization (CCTDP) contributions to the imaginary normal mode intensity of transition states. The results show that the imaginary bands are strong, ranging from 1217 to 16086 〖km∙mol〗^(-1), much higher than occurs for most bands found in molecules. For all systems, the CT contribution is responsible for 80% of the total intensity on average. The Charge contributions are slightly higher for transitions states with Z = F. Dipolar polarization contributions are always small. The contributions from the Z atoms are negligible, thus only atoms aligned with the reaction axis X-C-Y contribute to total intensity. All charge transfers were evaluated taking the carbon atom as reference, implying that almost all infrared intensity is determined by electron transfers from the nucleophile and carbon and from carbon to the leaving group. The mechanism of charge transfer revealed by the CCTDP model is consistent with the reaction mechanism itself, which points towards the connection between the imaginary normal mode and the reaction coordinate.

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Rincón, D. A., M. C. Daza, and M. Doerr. "Application of the quantum theory of atoms in molecules (QTAIM) to the study of the enzymatic kinetic resolution of propranolol, an amino alcohol with pharmaceutical applications." In VIII Simpósio de Estrutura Eletrônica e Dinâmica Molecular. Universidade de Brasília, 2020. http://dx.doi.org/10.21826/viiiseedmol2020135.

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Propranolol, ((R,S)-1-iso-propylamino-3-(1-naphthoxy)-2-propanol), is a β-adrenergic antagonist and is commercially available as a racemic mixture. Only the S-enantiomer has the desired therapeutic effect. Therefore, many researchers have been working on strategies to obtain S-propranolol with high enantiomeric purity. One approach to carry out the acetylation of (R,S)-Propranolol using Candida antarctica lipase B, CalB. This reaction leads to an enantiomeric purity of 96% at a relatively low conversion rate of 30 %. In our research group, we have been studying this reaction. The CalB active site is composed by the triad catalytic (ASP 187, HIS 224 and SER 105) and oxyanion hole (GLN 106 and THR 40). In a previous work, a QM/MM (Quantum Mechanics / Molecular Mechanics) study was carried out, using a QM region consisting only of the catalytic triad of CalB and (R,S)-propranolol [1]. In the present study, we investigate the effect of expanding the quantum region to include the oxyanion hole and to comprehend the effect of intermolecular hydrogen bonds present between the (R,S)-propranolol and the CalB active site. The electronic structure was analyzed using the Quantum Theory of Atoms In Molecules, QTAIM. Our results show that: 1. the studied reactions are more exothermic with the inclusion of the oxyanion hole than with only the catalytic triad. 2. the intermolecular interactions between (R,S)-propranolol and the CalB active site are dominated by hydrogen bonds (HB). Among those HBs, only one between propranolol and HIS 224, and another one between THR 40 and the carbonyl oxygen of acetylated SER 105 play an important role.

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Hall, David S., Michael Ray, Konstantin Tiurev, Emmi Ruokokoski, Andrei Horia Gheorghe, and Mikko Möttönen. "Tying Knots in a Quantum Fluid." In JSAP-OSA Joint Symposia. Washington, D.C.: Optica Publishing Group, 2017. http://dx.doi.org/10.1364/jsap.2017.7p_a410_6.

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Knots are familiar entities that appear at a captivating nexus of art, technology, mathematics, and science. They have recently attracted significant experimental interest, in contexts ranging from knotted DNA [1] and nanostructures [2] to nontrivial vortex knots in classical fluids [3]. Within classical field theories [4], knots have been proposed as the basis of fundamental particles, as well as explaining diverse persistent phenomena such as atoms and molecules [5].

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10

Phillips, Thomas G. "Millimeter and submillimeter wave astronomy." In OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1986. http://dx.doi.org/10.1364/oam.1986.mh3.

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The interstellar medium consists of diffuse clouds and dense clouds containing atoms, molecules, and dust particles at temperatures ranging from 3 to several hundred kelvins. The dense cloud gas particles are mostly molecular and the species found vary from simple molecules such as H2, CO, CS, HCN, etc. to heavy types such as the cyanopolyynes. Molecules other than symmetric ones, such as H2, have dipole moments and can be observed through their rotational transitions which lie in the millimeter and submillimeter bands. The emission line strengths as seen by large ground radio telescopes are usually in the 0.1-10 K range in terms of equivalent blackbody emission. Therefore, sensitive heterodyne detectors are used where noise temperatures are only about ten times the quantum limit. The most sensitive types employ SIS detector elements, which can be used in conjunction with focal plane antenna structures such as bow-ties. Many studies have been carried out including molecule identification, temperature and density measurements, and studies of dynamics of gas clouds in our galaxy and other galaxies.

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Reports on the topic "Quantum theory of atoms in molecules"

1

Barnett, R. N. Quantum Monte Carlo for atoms and molecules. Office of Scientific and Technical Information (OSTI), November 1989. http://dx.doi.org/10.2172/7040202.

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2

Langhoff, P. W., J. D. Mills, J. A. Boatz, and G. A. Gallup. Quantum-Mechanical Definition of Atoms and Chemical Bonds in Molecules. Fort Belvoir, VA: Defense Technical Information Center, January 2015. http://dx.doi.org/10.21236/ada626631.

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3

Byrd, Edward F. On the Failure of Correlating Partitioned Electrostatic Surface Potentials Using Bader's Atoms-in-Molecules Theory to Impact Sensitivities. Fort Belvoir, VA: Defense Technical Information Center, April 2013. http://dx.doi.org/10.21236/ada586396.

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4

GENERAL THEORY OF THE WHOLE PHYSICAL WORLD. SIB-Expertise, August 2022. http://dx.doi.org/10.12731/er0599.29072022.

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THE WORK CONSISTS IN COMBINING NEWTON'S CLASSICAL MECHANICS DESCRIBED BY EUCLIDIAN GEOMETRY, EINSTEIN'S GENERAL THEORY OF RELATIVITY, QUANTUM MECHANICS, THE THEORY OF SUPERSYMMETRY AND INFLATION THEORY ON THE BASIS OF THE BASIC LAW OF ECONOMIC HEALTH. THE PROPOSED THEORY, INCLUDING ALLOWS TO GIVE ANSWERS TO THE GLOBAL QUESTIONS OF TODAY'S COSMOLOGY AND ASTROPHYSICS: "WHAT WAS BEFORE THE BIG BANG?"; "WHAT IS DARK MATTER?"; "WHAT IS DARK ENERGY?"; “HOW TO UNDERSTAND PARALLEL WORLDS AND MULTI UNIVERSE''. THE WORK WILL SHOW A STRICT CORRELATION OF ALL INTERACTIONS (GRAVITATIONAL, ELECTROMAGNETIC, WEAK AND STRONG) BETWEEN PARTICLES OF MATTER, BOTH ON THE SCALE OF THE GALACTIC SYSTEM AND AT THE LEVEL OF NUCLEI OF ATOMS AND UNSTABLE OUTSIDE ATOMIC NUCLEI OF SUBATOMIC NUCLEI. THESE INTERACTIONS FORMED THE OBSERVABLE PICTURE OF THE WORLD.

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5

GENERAL THEORY OF THE WHOLE PHYSICAL WORLD. SIB-Expertise, August 2022. http://dx.doi.org/10.12731/er0599.10082022.

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THE WORK CONSISTS IN COMBINING NEWTON'S CLASSICAL MECHANICS DESCRIBED BY EUCLIDIAN GEOMETRY, EINSTEIN'S GENERAL THEORY OF RELATIVITY, QUANTUM MECHANICS, THE THEORY OF SUPERSYMMETRY AND INFLATION THEORY ON THE BASIS OF THE BASIC LAW OF ECONOMIC HEALTH. THE PROPOSED THEORY, INCLUDING ALLOWS TO GIVE ANSWERS TO THE GLOBAL QUESTIONS OF TODAY'S COSMOLOGY AND ASTROPHYSICS: "WHAT WAS BEFORE THE BIG BANG?"; "WHAT IS DARK MATTER?"; "WHAT IS DARK ENERGY?"; “HOW TO UNDERSTAND PARALLEL WORLDS AND MULTI UNIVERSE''. THE WORK WILL SHOW A STRICT CORRELATION OF ALL INTERACTIONS (GRAVITATIONAL, ELECTROMAGNETIC, WEAK AND STRONG) BETWEEN PARTICLES OF MATTER, BOTH ON THE SCALE OF THE GALACTIC SYSTEM AND AT THE LEVEL OF NUCLEI OF ATOMS AND UNSTABLE OUTSIDE ATOMIC NUCLEI OF SUBATOMIC NUCLEI. THESE INTERACTIONS FORMED THE OBSERVABLE PICTURE OF THE WORLD.

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