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Johnson, Jeffrey Allan. "The Case of the Missing German Quantum Chemists." Historical Studies in the Natural Sciences 43, no. 4 (November 2012): 391–452. http://dx.doi.org/10.1525/hsns.2013.43.4.391.
This paper discusses factors limiting the development of a modern, quantum-based chemistry in Nazi Germany. The first part presents a case study of industrial research in Nazi Germany that suggests the delayed introduction of space-filling molecular models into structural analysis and synthesis in industrial organic chemistry, almost a decade after their invention by a German physicist. Was this symptomatic of a broader pattern of neglect of quantum chemistry in Nazi Germany? To answer this question this paper examines the origins of such models, and their appearance (or not) in selected textbooks and monographs dealing with problems in the interdisciplinary borderland between the physical and organic dimensions of chemistry. While it appears that those on the physical side were more comfortable with such models than those on the organic side, it is also clear that even a theoretically unsophisticated organic chemist could learn to use these models effectively, without necessarily understanding the intricacies of the quantum chemistry on which they were based. Why then were they not better integrated into mainstream chemical education? To this end the second part discusses three phases (pre-1933, 1933–38, 1939–43) of the broader scientific, institutional, and political contexts of efforts to reform or “modernize” chemical education among many groups in Germany, particularly through the Association of Laboratory Directors in German Universities and Colleges, the autonomous group that administered the predoctoral qualifying examination (Association Examination) for chemistry students until its dissolution in 1939 by the Education Ministry and the establishment of the first official certifying examination and associated title for chemists, the Diplom-Chemiker (certified chemist). Continuing debates modified the examination in 1942–43, but given the limitations imposed by the political and wartime contexts, and the need to accelerate chemical training for the purposes of industrial and military mobilization, the resulting chemical education could not produce students adequately trained in the modern physical science emerging elsewhere in the world. Quantum chemists remained missing in action in Nazi Germany.
Rempel, A. A., O. V. Ovchinnikov, I. A. Weinstein, S. V. Rempel, Yu V. Kuznetsova, A. V. Naumov, M. S. Smirnov, I. Yu Eremchev, A. S. Vokhmintsev, and S. S. Savchenko. "Quantum dots: modern methods of synthesis and optical properties." Russian Chemical Reviews 93, no. 4 (April 2024): RCR5114. http://dx.doi.org/10.59761/rcr5114.
Quantum dots are the most exciting representatives of nanomaterials. They are synthesized by modern methods of nanotechnology pertaining to both inorganic and organic chemistry. Quantum dots possess unique physical and chemical properties; therefore, they are used in very different fields of physics, chemistry, biology, engineering and medicine. It is not surprising that the Nobel Prize in chemistry in 2023 was given for discovery and synthesis of quantum dots. In this review, modern methods of synthesis of quantum dots, their optical properties and practical applications are analyzed. In the beginning, a short historical background of quantum dots is given. Many gifted scientists, including chemists and physicists, were engaged in these studies. The synthesis of quantum dots in solid and liquid matrices is described in detail. Quantum dots are well-known owing to their unique optical properties, that is why the attention in the review is focused on the quantum-size effect. The causes for fascinating blinking of quantum dots and techniques for observation of a single quantum dot are explained. The last part of the review describes important applications of quantum dots in biology, medicine and quantum technologies.<br> Bibliography — 772 references.
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Clark, Timothy, and Martin G. Hicks. "Models of necessity." Beilstein Journal of Organic Chemistry 16 (July 13, 2020): 1649–61. http://dx.doi.org/10.3762/bjoc.16.137.
The way chemists represent chemical structures as two-dimensional sketches made up of atoms and bonds, simplifying the complex three-dimensional molecules comprising nuclei and electrons of the quantum mechanical description, is the everyday language of chemistry. This language uses models, particularly of bonding, that are not contained in the quantum mechanical description of chemical systems, but has been used to derive machine-readable formats for storing and manipulating chemical structures in digital computers. This language is fuzzy and varies from chemist to chemist but has been astonishingly successful and perhaps contributes with its fuzziness to the success of chemistry. It is this creative imagination of chemical structures that has been fundamental to the cognition of chemistry and has allowed thought experiments to take place. Within the everyday language, the model nature of these concepts is not always clear to practicing chemists, so that controversial discussions about the merits of alternative models often arise. However, the extensive use of artificial intelligence (AI) and machine learning (ML) in chemistry, with the aim of being able to make reliable predictions, will require that these models be extended to cover all relevant properties and characteristics of chemical systems. This, in turn, imposes conditions such as completeness, compactness, computational efficiency and non-redundancy on the extensions to the almost universal Lewis and VSEPR bonding models. Thus, AI and ML are likely to be important in rationalizing, extending and standardizing chemical bonding models. This will not affect the everyday language of chemistry but may help to understand the unique basis of chemical language.
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Barden, Christopher J., and Henry F. Schaefer. "Quantum chemistry in the 21st century (Special topic article)." Pure and Applied Chemistry 72, no. 8 (January 1, 2000): 1405–23. http://dx.doi.org/10.1351/pac200072081405.
Quantum chemistry is the field in which solutions to the Schrödinger equation are used to predict the properties of molecules and solve chemical problems. This paper considers possible future research directions in light of the discipline's past successes. After decades of incremental development—accompanied by a healthy dose of skepticism from the experimental community—the ready availability of fast computers has ushered in a "golden age" of quantum chemistry. In this new era of acceptance, theoretical predictions often precede experiment in small molecule chemistry, and quantum chemical methods play an ever greater role in biochemical and other larger systems. Quantum chemists increasingly divide their efforts along three fronts: high-level (spectroscopic) accuracy for small molecules, characterized by such techniques as Brueckner methods, r12 formalisms, and multireference calculations; parameterization- or extrapolation-based intermediate-level schemes (such as Gaussian-N theory) for medium molecules; and lower-level (chemical) accuracy for large molecules, characterized by density functional theory and linear scaling techniques. These tools, and quantum chemistry as a whole, are examined here from a historical perspective and with a view toward their future applications.
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Makushin, K. M., M. D. Sapova, and A. K. Fedorov. "Quantum computing library for quantum chemistry applications." Journal of Physics: Conference Series 2701, no. 1 (February 1, 2024): 012032. http://dx.doi.org/10.1088/1742-6596/2701/1/012032.
Abstract Quantum computing is aimed to solve tasks, which are believed to be exponentially hard to existing computational devices and tools. A prominent example of such classically hard problems is simulating complex quantum many-body systems, in particular, for quantum chemistry. However, solving realistic quantum chemistry problems with quantum computers encounters various difficulties, which are related, first, to limited computational capabilities of existing quantum devices and, second, to the efficiency of algorithmic approaches. In the present work, we address the algorithmic side of quantum chemistry applications by introducing a Python 3 code library, whose primary objective is to speed up the development of variational quantum algorithms for electronic structure problems. We describe the various features and capabilities of this library, including its ease in constructing customized versions of variational quantum algorithms. We elucidate how the developed library allows one to design quantum circuits and enable for the efficient execution of quantum algorithms. Furthermore, the library facilitates the integration of classical and quantum algorithms for hybrid computations and helps to realize the cross-verification of data with traditional computational methods, thereby enhancing the overall reliability of quantum chemistry simulations.
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Arrazola, Juan Miguel, Olivia Di Matteo, Nicolás Quesada, Soran Jahangiri, Alain Delgado, and Nathan Killoran. "Universal quantum circuits for quantum chemistry." Quantum 6 (June 20, 2022): 742. http://dx.doi.org/10.22331/q-2022-06-20-742.
Universal gate sets for quantum computing have been known for decades, yet no universal gate set has been proposed for particle-conserving unitaries, which are the operations of interest in quantum chemistry. In this work, we show that controlled single-excitation gates in the form of Givens rotations are universal for particle-conserving unitaries. Single-excitation gates describe an arbitrary U(2) rotation on the two-qubit subspace spanned by the states |01⟩,|10⟩, while leaving other states unchanged – a transformation that is analogous to a single-qubit rotation on a dual-rail qubit. The proof is constructive, so our result also provides an explicit method for compiling arbitrary particle-conserving unitaries. Additionally, we describe a method for using controlled single-excitation gates to prepare an arbitrary state of a fixed number of particles. We derive analytical gradient formulas for Givens rotations as well as decompositions into single-qubit and CNOT gates. Our results offer a unifying framework for quantum computational chemistry where every algorithm is a unique recipe built from the same universal ingredients: Givens rotations.
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Hastings, Matthew B., Dave Wecker, Bela Bauer, and Matthias Troyer. "Improving quantum algorithms for quantum chemistry." Quantum Information and Computation 15, no. 1&2 (January 2015): 1–21. http://dx.doi.org/10.26421/qic15.1-2-1.
We present several improvements to the standard Trotter-Suzuki based algorithms used in the simulation of quantum chemistry on a quantum computer. First, we modify how Jordan-Wigner transformations are implemented to reduce their cost from linear or logarithmic in the number of orbitals to a constant. Our modification does not require additional ancilla qubits. Then, we demonstrate how many operations can be parallelized, leading to a further linear decrease in the parallel depth of the circuit, at the cost of a small constant factor increase in number of qubits required. Thirdly, we modify the term order in the Trotter-Suzuki decomposition, significantly reducing the error at given Trotter-Suzuki timestep. A final improvement modifies the Hamiltonian to reduce errors introduced by the non-zero Trotter-Suzuki timestep. All of these techniques are validated using numerical simulation and detailed gate counts are given for realistic molecules.
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2006. Vita. Includes bibliographical references (p. 247-254). The reaction matrix of multichannel quantum defect theory, K, gives a complete picture of the electronic structure and the electron - nuclear dynamics for a molecule. The reaction matrix can be used to examine both bound states and free electron scattering properties of molecular systems, which are characterized by a Rydberg/scattering electron incident on an ionic-core. An ab initio computation of the reaction matrix for fixed molecular geometries is a substantive but important theoretical effort. In this thesis, a generalized quantum defect method is presented for determining the reaction matrix in a form which minimizes its energy dependence. This reaction matrix method is applied to the Rydberg electronic structure of Calcium monofluoride. The spectroscopic quantum defects for the ... states of CaF are computed using an effective one-electron calculation. Good agreement with the experimental values is obtained. The E-symmetry eigenquantum defects obtained from the CaF reaction matrix are found to have an energy dependence characteristic of a resonance. The analysis shows that the main features of the energy-dependent structure in the eigenphases are a consequence of a broad shape resonance in the 2E+ Rydberg series. (cont.) This short-lived resonance is spread over the entire 2E+ Rydberg series and extends well into the ionization continuum. The effect of the shape resonance is manifested as a global "scarring" of the Rydberg spectrum, which is distinct from the more familiar local level-perturbations. This effect has been unnoticed in previous analyses. The quantum chemical foundation of the quantum defect method is established by a many-electron generalization of the reaction matrix calculation. Test results that validate the many-electron theory are presented for the quantum defects of the lsagnpo, E+ Rydberg series of the hydrogen molecule. It is possible that the reaction matrix calculations on CaF and H2 can pave the way for a novel type of quantum chemistry that aims to calculate the electronic structure over the entire bound-state region, as opposed to the current methods that focus on state by state calculations. by Serhan Altunata. Ph.D.
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Njegic, Bosiljka. "Cooking up quantum chemistry." [Ames, Iowa : Iowa State University], 2008.
Rudberg, Elias. "Quantum Chemistry for Large Systems." Doctoral thesis, Stockholm : Bioteknologi, Kungliga Tekniska högskolan, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4561.
Gilbert, A. T. B. "Density methods in quantum chemistry." Thesis, University of Cambridge, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.599402.
Density functional theory (DFT) has become a central aspect of quantum chemistry and provides the mainstay of chemical calculations. The advantage of DFT methods lies in their relatively inexpensive computational cost and their dealing with an experimentally tangible quantity, i.e. the density. The chief drawback is its lack of well-defined path from approximation to exactitude. Consequently many models and approaches have emerged, and been enthusiastically advocated, often with little more justification than "it works". This thesis begins with an overview of traditional quantum chemical theory and methods, and places DFT within this framework. In chapters 5 and 6 new model systems are presented, and novel methods to derive exchange functionals that are exact for these model systems are developed. By taking this approach, rather than the more pragmatic one of data fitting, the successes and failures can be traced to the underlying soundness of the model and/or the method used in the derivation. In the development of these functionals some difficulties were encountered with convergence of the self-consistent field calculations. These problems are addressed in chapter 7. The observation that a molecular density is very close to that given by the superposition of its constituent atoms, leads naturally to the idea of modelling a density by a sum of nuclear centred, spherically symmetric 'Stewart Atoms'. However, attempts at constructing Stewart atoms in the past have been thwarted by slow basis set convergence. In chapter 8 we overview the work that has been undertaken on Stewart atoms and present several formalisms in which the theory has been developed. Chapter 9 deals with the problem of constructing accurate representations of Stewart atoms. Several different approaches are considered and the most accurate is determined. Applications of the Stewart atoms are considered in chapter 10.
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Strange, Robin. "Electron correlation in quantum chemistry." Thesis, University of Birmingham, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289793.
Murray, Christopher William. "Quantum chemistry for large molecules." Thesis, University of Cambridge, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317841.
Rubensson, Emanuel H. "Matrix Algebra for Quantum Chemistry." Doctoral thesis, Stockholm : Bioteknologi, Kungliga Tekniska högskolan, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-9447.
Pye, Cory C. "Applications of optimization to quantum chemistry." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/nq23109.pdf.
Cette thèse se concentre sur les calculs et la visualisation des propriétés moléculaires dans le cadre relativiste à quatre composantes. La théorie des réponses linéaire et quadratiquecombinée avec la théorie de la fonctionnelle de la densité (DFT) Kohn-Sham sont les outils principaux utilisés dans ce travail. Nous avons présenté la mise en oeuvre relativiste à quatre composantes des réponses linéaire et quadratique dans des systèmes à couche fermée dans le cadre de la DFT dépendant du temps avec la contribution de la densité de spin non-colinéaire. Cette thèse contient les premières études Hartree-Fock relativiste à quatre composantes des contributions électrofaibles de la non-conservation de la parité des paramètres spectraux de la résonance magnétique nucléaire. Nous avons introduit une approche visuelle des propriétés moléculaires au deuxième ordre statiques et dépendant de la fréquence dans l'espace physique à trois dimensions dans le cadre relativiste à quatre composantes. Nous avons démontré comment des perturbations statiques peuvent être imposées et visualisées en utilisant la méthode des perturbations finies This thesis focuses on the calculation and visualization of molecular properties within the 4-component relativistic framework. Response theory together with density functional theory (DFT) within the Kohn-Sham approach are the main tools. The implementation of closed-shell linear and quadratic response functions within time-dependent DFT in the 4-component relativistic framework is presented with extensions that include contributions from the spin density. This thesis contains the first 4-component relativistic Hartree-Fock study of parity-violating effects on nuclear magnetic resonance parameters. An analytical real-space approach to frequency-dependent second-order molecular properties within the 4-component relativistic framework is introduced together with tools for the visualization of higher-order molecular properties based on the finite perturbation approach
Tsuneda, Takao. "Quantum Chemistry." In Density Functional Theory in Quantum Chemistry, 1–33. Tokyo: Springer Japan, 2014. http://dx.doi.org/10.1007/978-4-431-54825-6_1.
Battaglia, Franco, and Thomas F. George. "Quantum Chemistry." In Fundamentals in Chemical Physics, 141–82. Dordrecht: Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-017-1636-9_4.
Handy, Nicholas C., and S. F. Boys. "Quantum chemistry." In 100 Years of Physical Chemistry, 57–66. Cambridge: Royal Society of Chemistry, 2007. http://dx.doi.org/10.1039/9781847550002-00057.
Pène, Olivier, Karl Jansen, Norman H. Christ, Norman H. Christ, and Salvador Coll. "Quantum Chemistry." In Encyclopedia of Parallel Computing, 1689. Boston, MA: Springer US, 2011. http://dx.doi.org/10.1007/978-0-387-09766-4_2418.
Тези доповідей конференцій з теми "Quantum chemistry":
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Maroulis, George. "Computational quantum chemistry." In INTERNATIONAL CONFERENCE OF COMPUTATIONAL METHODS IN SCIENCES AND ENGINEERING 2009: (ICCMSE 2009). AIP, 2012. http://dx.doi.org/10.1063/1.4771781.
Ellinger, Yves. "The Quantum Chemistry alternative." In Second international conference on atomic and molecular data and their applications. AIP, 2000. http://dx.doi.org/10.1063/1.1336283.
Fedorov, Dmitry, Matthew Otten, Byeol Kang, Anouar Benali, Salman Habib, Stephen Gray, and Yuri Alexeev. "Quantum Resource Estimation for Quantum Chemistry Algorithms." In 2022 IEEE International Conference on Quantum Computing and Engineering (QCE). IEEE, 2022. http://dx.doi.org/10.1109/qce53715.2022.00144.
The AQGD optimization technique requires the presence of some specific gates in the quantum circuit and the hydrogen molecule simulation using AQGD in a VQA reveals the incompatibility of Unitary Coupled-Cluster ansatz with the method. Further, varying the parameters of the optimizer results in a significant reduction of simulation run-time.
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Freedman, Danna. "Chemistry for quantum information science." In Quantum Sensing, Imaging, and Precision Metrology, edited by Selim M. Shahriar and Jacob Scheuer. SPIE, 2023. http://dx.doi.org/10.1117/12.2657322.
Yuan, Zhiyang, Lila V. H. Rodgers, Jared Rovny, Sorawis Sangtawesin, Srikanth Srinivasan, James Allred, Nathalie P. de Leon, and Patryk Gumann. "Ultrahigh Vacuum Surface Chemistry For Nanoscale Sensors In Diamond." In Quantum 2.0. Washington, D.C.: Optica Publishing Group, 2022. http://dx.doi.org/10.1364/quantum.2022.qtu2a.11.
We have constructed a unique cluster tool for surface preparation and spectroscopy in ultrahigh vacuum combined with cryogenic, confocal microscopy of single nitrogen vacancy centers in diamond. We modify the diamond surface chemistry and investigate shallow nitrogen vacancy center properties in situ.
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"THE CROSS-PLATFORM QUANTUM CHEMISTRY SOFTWARE FOR COLLEGE CHEMISTRY EDUCATION." In 2nd International Conference on Computer Supported Education. SciTePress - Science and and Technology Publications, 2010. http://dx.doi.org/10.5220/0002793104380441.
Perera, Ajith, Theodore E. Simos, and George Maroulis. "Predictive Quantum Chemistry: A Step Toward “Chemistry Without Test Tubes”." In COMPUTATIONAL METHODS IN SCIENCE AND ENGINEERING: Theory and Computation: Old Problems and New Challenges. Lectures Presented at the International Conference on Computational Methods in Science and Engineering 2007 (ICCMSE 2007): VOLUME 1. AIP, 2007. http://dx.doi.org/10.1063/1.2835948.
Ma, Jonathan H., Han Wang, David Prendergast, Andrew R. Neureuther, and Patrick Naulleau. "Investigating EUV radiation chemistry with first principle quantum chemistry calculations." In International Conference on Extreme Ultraviolet Lithography 2019, edited by Kurt G. Ronse, Paolo A. Gargini, Patrick P. Naulleau, and Toshiro Itani. SPIE, 2019. http://dx.doi.org/10.1117/12.2538558.
Yuen-Zhou, Joel. "Controlling chemistry with vibrational polaritons." In Conference on Coherence and Quantum Optics. Washington, D.C.: OSA, 2019. http://dx.doi.org/10.1364/cqo.2019.w4b.4.
Aspuru-Guzik, Alan. Quantum Computing for Quantum Chemistry. Fort Belvoir, VA: Defense Technical Information Center, September 2010. http://dx.doi.org/10.21236/ada534093.
Author, Not Given. Computational quantum chemistry website. Office of Scientific and Technical Information (OSTI), August 1997. http://dx.doi.org/10.2172/7376091.
Taube, Andrew Garvin. Steps toward fault-tolerant quantum chemistry. Office of Scientific and Technical Information (OSTI), May 2010. http://dx.doi.org/10.2172/992330.
Umrigar, Cyrus J. Quantum Chemistry via Walks in Determinant Space. Office of Scientific and Technical Information (OSTI), January 2016. http://dx.doi.org/10.2172/1233718.
C. F. Melius and M. D. Allendorf. Bond additivity corrections for quantum chemistry methods. Office of Scientific and Technical Information (OSTI), April 1999. http://dx.doi.org/10.2172/751014.
Sholl, David. Quantum Chemistry for Surface Segregation in Metal Alloys. Office of Scientific and Technical Information (OSTI), August 2006. http://dx.doi.org/10.2172/1109080.
Hollingsworth, Jennifer. Advanced Quantum Emitters: Chemistry, Photophysics, Integration and Application. Office of Scientific and Technical Information (OSTI), May 2021. http://dx.doi.org/10.2172/1781363.
Harrison, Robert J., David E. Bernholdt, Bruce E. Bursten, Wibe A. De Jong, David A. Dixon, Kenneth G. Dyall, Walter V. Ermler, et al. Computational Chemistry for Nuclear Waste Characterization and Processing: Relativistic Quantum Chemistry of Actinides. Office of Scientific and Technical Information (OSTI), August 2002. http://dx.doi.org/10.2172/15010139.
Jones, H. W., and C. A. Weatherford. Analytical Methods Using Slater-Type Orbitals in Quantum Chemistry. Fort Belvoir, VA: Defense Technical Information Center, March 1992. http://dx.doi.org/10.21236/ada251044.
Mun, Eundeok. Yb-based heavy fermion compounds and field tuned quantum chemistry. Office of Scientific and Technical Information (OSTI), January 2010. http://dx.doi.org/10.2172/985312.
