CHEM 743 “Quantum Chemistry” S'15
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Mercury 2.4 User Guide and Tutorials 2011 CSDS Release
Mercury 2.4 User Guide and Tutorials 2011 CSDS Release Copyright © 2010 The Cambridge Crystallographic Data Centre Registered Charity No 800579 Conditions of Use The Cambridge Structural Database System (CSD System) comprising all or some of the following: ConQuest, Quest, PreQuest, Mercury, (Mercury CSD and Materials module of Mercury), VISTA, Mogul, IsoStar, SuperStar, web accessible CSD tools and services, WebCSD, CSD Java sketcher, CSD data file, CSD-UNITY, CSD-MDL, CSD-SDfile, CSD data updates, sub files derived from the foregoing data files, documentation and command procedures (each individually a Component) is a database and copyright work belonging to the Cambridge Crystallographic Data Centre (CCDC) and its licensors and all rights are protected. Use of the CSD System is permitted solely in accordance with a valid Licence of Access Agreement and all Components included are proprietary. When a Component is supplied independently of the CSD System its use is subject to the conditions of the separate licence. All persons accessing the CSD System or its Components should make themselves aware of the conditions contained in the Licence of Access Agreement or the relevant licence. In particular: • The CSD System and its Components are licensed subject to a time limit for use by a specified organisation at a specified location. • The CSD System and its Components are to be treated as confidential and may NOT be disclosed or re- distributed in any form, in whole or in part, to any third party. • Software or data derived from or developed using the CSD System may not be distributed without prior written approval of the CCDC. -
GROMACS: Fast, Flexible, and Free
GROMACS: Fast, Flexible, and Free DAVID VAN DER SPOEL,1 ERIK LINDAHL,2 BERK HESS,3 GERRIT GROENHOF,4 ALAN E. MARK,4 HERMAN J. C. BERENDSEN4 1Department of Cell and Molecular Biology, Uppsala University, Husargatan 3, Box 596, S-75124 Uppsala, Sweden 2Stockholm Bioinformatics Center, SCFAB, Stockholm University, SE-10691 Stockholm, Sweden 3Max-Planck Institut fu¨r Polymerforschung, Ackermannweg 10, D-55128 Mainz, Germany 4Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, NL-9747 AG Groningen, The Netherlands Received 12 February 2005; Accepted 18 March 2005 DOI 10.1002/jcc.20291 Published online in Wiley InterScience (www.interscience.wiley.com). Abstract: This article describes the software suite GROMACS (Groningen MAchine for Chemical Simulation) that was developed at the University of Groningen, The Netherlands, in the early 1990s. The software, written in ANSI C, originates from a parallel hardware project, and is well suited for parallelization on processor clusters. By careful optimization of neighbor searching and of inner loop performance, GROMACS is a very fast program for molecular dynamics simulation. It does not have a force field of its own, but is compatible with GROMOS, OPLS, AMBER, and ENCAD force fields. In addition, it can handle polarizable shell models and flexible constraints. The program is versatile, as force routines can be added by the user, tabulated functions can be specified, and analyses can be easily customized. Nonequilibrium dynamics and free energy determinations are incorporated. Interfaces with popular quantum-chemical packages (MOPAC, GAMES-UK, GAUSSIAN) are provided to perform mixed MM/QM simula- tions. The package includes about 100 utility and analysis programs. -
Quantum Crystallography†
Chemical Science View Article Online MINIREVIEW View Journal | View Issue Quantum crystallography† Simon Grabowsky,*a Alessandro Genoni*bc and Hans-Beat Burgi*de Cite this: Chem. Sci.,2017,8,4159 ¨ Approximate wavefunctions can be improved by constraining them to reproduce observations derived from diffraction and scattering experiments. Conversely, charge density models, incorporating electron-density distributions, atomic positions and atomic motion, can be improved by supplementing diffraction Received 16th December 2016 experiments with quantum chemically calculated, tailor-made electron densities (form factors). In both Accepted 3rd March 2017 cases quantum chemistry and diffraction/scattering experiments are combined into a single, integrated DOI: 10.1039/c6sc05504d tool. The development of quantum crystallographic research is reviewed. Some results obtained by rsc.li/chemical-science quantum crystallography illustrate the potential and limitations of this field. 1. Introduction today's organic, inorganic and physical chemistry. These tools are usually employed separately. Diffraction and scattering Quantum chemistry methods and crystal structure determina- experiments provide structures at the atomic scale, while the Creative Commons Attribution 3.0 Unported Licence. tion are highly developed research tools, indispensable in techniques of quantum chemistry provide wavefunctions and aUniversitat¨ Bremen, Fachbereich 2 – Biologie/Chemie, Institut fur¨ Anorganische eUniversitat¨ Zurich,¨ Institut fur¨ Chemie, Winterthurerstrasse 190, CH-8057 Zurich,¨ Chemie und Kristallographie, Leobener Str. NW2, 28359 Bremen, Germany. Switzerland E-mail: [email protected] † Dedicated to Prof. Louis J. Massa on the occasion of his 75th birthday and to bCNRS, Laboratoire SRSMC, UMR 7565, Vandoeuvre-l`es-Nancy, F-54506, France Prof. Dylan Jayatilaka on the occasion of his 50th birthday in recognition of their cUniversit´e de Lorraine, Laboratoire SRSMC, UMR 7565, Vandoeuvre-l`es-Nancy, F- pioneering contributions to the eld of X-ray quantum crystallography. -
Quantum Reform
feature Quantum reform Leonie Mueck Quantum computers potentially offer a faster way to calculate chemical properties, but the exact implications of this speed-up have only become clear over the last year. The first quantum computers are likely to enable calculations that cannot be performed classically, which might reform quantum chemistry — but we should not expect a revolution. t had been an exhausting day at the 2012 International Congress of Quantum IChemistry with countless presentations reporting faster and more accurate methods for calculating chemical information using computers. In the dry July heat of Boulder, Colorado, a bunch of young researchers decided to end the day with a cool beer, but the scientific discussion didn’t fade away. Thoughts on the pros and cons of all the methods — the approximations they involved and the chemical problems that they could solve — bounced across the table, until somebody said “Anyway, in a few years we will have a quantum computer and our approximate methods will be obsolete”. An eerie silence followed. What a frustrating thought! They were devoting their careers to quantum chemistry — working LIBRARY PHOTO RICHARD KAIL/SCIENCE tirelessly on applying the laws of quantum mechanics to treat complex chemical of them offering a different trade-off between cannot do on a ‘classical’ computer, it does problems with a computer. And in one fell accuracy and computational feasibility. not look like all the conventional quantum- swoop, would all of those efforts be wasted Enter the universal quantum computer. chemical methods will become obsolete or as chemists turn to quantum computers and This dream machine would basically work that quantum chemists will be out of their their enormous computing power? like a normal digital computer; it would jobs in the foreseeable future. -
Quantum Chemistry and Spectroscopy – Spring 2018
CHE 336 – Quantum Chemistry and Spectroscopy – Spring 2018 Instructor: Dr. Jessica Sarver Email: [email protected] Office: HSC 364 (email hours: 8 am – 10 pm) Office Hours: 10am-12pm Tuesday, 2-3pm Wednesday, 10:30-11:30am Friday, or by appointment Course Description (from Westminster undergraduate catalog) Quantum chemistry and spectroscopy is the study of the microscopic behavior of matter and its interaction with electromagnetic radiation. Topics include the formulation and application of quantum mechanical models, atomic and molecular structure, and various spectroscopic techniques. Laboratory activities demonstrate the fundamental principles of physical chemistry. Methods that will be used during the laboratory portion include: polarimetry, UV-Vis and fluorescence spectroscopies, electrochemistry, and computational/molecular modeling. Prerequisites: C- grade in CHE 117 and MTH 152 and PHY 152. Course Outcomes The chemistry major outcomes are: • Describe and explain quantum theory and the three quantum mechanical models of motion. • Describe and explain how these theories/models are applied and incorporated to applications of atomic/molecular structure and spectroscopy. • Describe and explain the principles of four major types of spectroscopy and their applications. • Describe and explain the measurable thermodynamic parameters for physical and chemical processes and equilibria. • Describe and explain how chemical kinetics can be used to investigate time-dependent processes. • Solve mathematical problems based on physical chemical principles and connect the numerical results with these principles. Textbook The text for this course is Physical Chemistry, 10th Ed. by Atkins and de Paula. Readings and problem set questions will be assigned from this text. You are strongly urged to get a copy of this textbook and complete all the assigned readings and homework. -
Complex Chemical Reaction Networks from Heuristics-Aided Quantum Chemistry
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Harvard University - DASH Complex Chemical Reaction Networks from Heuristics-Aided Quantum Chemistry The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters. Citation Rappoport, Dmitrij, Cooper J. Galvin, Dmitry Zubarev, and Alán Aspuru-Guzik. 2014. “Complex Chemical Reaction Networks from Heuristics-Aided Quantum Chemistry.” Journal of Chemical Theory and Computation 10 (3) (March 11): 897–907. Published Version doi:10.1021/ct401004r Accessed February 19, 2015 5:14:37 PM EST Citable Link http://nrs.harvard.edu/urn-3:HUL.InstRepos:12697373 Terms of Use This article was downloaded from Harvard University's DASH repository, and is made available under the terms and conditions applicable to Open Access Policy Articles, as set forth at http://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of- use#OAP (Article begins on next page) Complex Chemical Reaction Networks from Heuristics-Aided Quantum Chemistry Dmitrij Rappoport,∗,† Cooper J Galvin,‡ Dmitry Yu. Zubarev,† and Alán Aspuru-Guzik∗,† Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, MA 02138, USA, and Pomona College, 333 North College Way, Claremont, CA 91711, USA E-mail: [email protected]; [email protected] Abstract While structures and reactivities of many small molecules can be computed efficiently and accurately using quantum chemical methods, heuristic approaches remain essential for mod- eling complex structures and large-scale chemical systems. Here we present heuristics-aided quantum chemical methodology applicable to complex chemical reaction networks such as those arising in metabolism and prebiotic chemistry. -
Introduction to Quantum Chemistry
Chem. 140B Dr. J.A. Mack Introduction to Quantum Chemistry Why as a chemist, do you need to learn this material? 140B Dr. Mack 1 Without Quantum Mechanics, how would you explain: • Periodic trends in properties of the elements • Structure of compounds e.g. Tetrahedral carbon in ethane, planar ethylene, etc. • Bond lengths/strengths • Discrete spectral lines (IR, NMR, Atomic Absorption, etc.) • Electron Microscopy & surface science Without Quantum Mechanics, chemistry would be a purely empirical science. (We would be no better than biologists…) 140B Dr. Mack 2 1 Classical Physics On the basis of experiments, in particular those performed by Galileo, Newton came up with his laws of motion: 1. A body moves with a constant velocity (possibly zero) unless it is acted upon by a force. 2. The “rate of change of motion”, i.e. the rate of change of momentum, is proportional to the impressed force and occurs in the direction of the applied force. 3. To every action there is an equal and opposite reaction. 4. The gravitational force of attraction between two bodies is proportional to the product of their masses and inversely proportional to the square of the distance between them. m m F = G × 1 2 r 2 140B Dr. Mack 3 The Failures of Classical Mechanics 1. Black Body Radiation: The Ultraviolet Catastrophe 2. The Photoelectric Effect: Einstein's belt buckle 3. The de Broglie relationship: Dude you have a wavelength! 4. The double-slit experiment: More wave/particle duality 5. Atomic Line Spectra: The 1st observation of quantum levels 140B Dr. Mack 4 2 Black Body Radiation Light Waves: Electromagnetic Radiation Light is composed of two perpendicular oscillating vectors waves: A magnetic field & an electric field As the light wave passes through a substance, the oscillating fields can stimulate the movement of electrons in a substance. -
Computational Analysis of the Mechanism of Chemical Reactions
Computational Analysis of the Mechanism of Chemical Reactions in Terms of Reaction Phases: Hidden Intermediates and Hidden Transition States ELFI KRAKA* AND DIETER CREMER Department of Chemistry, Southern Methodist University, 3215 Daniel Avenue, Dallas, Texas 75275-0314 RECEIVED ON JANUARY 9, 2009 CON SPECTUS omputational approaches to understanding chemical reac- Ction mechanisms generally begin by establishing the rel- ative energies of the starting materials, transition state, and products, that is, the stationary points on the potential energy surface of the reaction complex. Examining the intervening spe- cies via the intrinsic reaction coordinate (IRC) offers further insight into the fate of the reactants by delineating, step-by- step, the energetics involved along the reaction path between the stationary states. For a detailed analysis of the mechanism and dynamics of a chemical reaction, the reaction path Hamiltonian (RPH) and the united reaction valley approach (URVA) are an effi- cient combination. The chemical conversion of the reaction complex is reflected by the changes in the reaction path direction t(s) and reaction path curvature k(s), both expressed as a function of the path length s. This information can be used to partition the reaction path, and by this the reaction mech- anism, of a chemical reaction into reaction phases describing chemically relevant changes of the reaction complex: (i) a contact phase characterized by van der Waals interactions, (ii) a preparation phase, in which the reactants prepare for the chemical processes, (iii) one or more transition state phases, in which the chemical processes of bond cleavage and bond formation take place, (iv) a product adjustment phase, and (v) a separation phase. -
Six Phases of Cosmic Chemistry
Six Phases of Cosmic Chemistry Lukasz Lamza The Pontifical University of John Paul II Department of Philosophy, Chair of Philosophy of Nature Kanonicza 9, Rm. 203 31-002 Kraków, Poland e-mail: [email protected] 1. Introduction The steady development of astrophysical and cosmological sciences has led to a growing appreciation of the continuity of cosmic history throughout which all known phenomena come to being. This also includes chemical phenomena and there are numerous theoretical attempts to rewrite chemistry as a “historical” science (Haken 1978; Earley 2004). It seems therefore vital to organize the immense volume of chemical data – from astrophysical nuclear chemistry to biochemistry of living cells – in a consistent and quantitative fashion, one that would help to appreciate the unfolding of chemical phenomena throughout cosmic time. Although numerous specialist reviews exist (e.g. Shaw 2006; Herbst 2001; Hazen et al. 2008) that illustrate the growing appreciation for cosmic chemical history, several issues still need to be solved. First of all, such works discuss only a given subset of cosmic chemistry (astrochemistry, chemistry of life etc.) using the usual tools and languages of these particular disciplines which does not facilitate drawing large-scale conclusions. Second, they discuss the history of chemical structures and not chemical processes – which implicitly leaves out half of the totality chemical phenomena as non-historical. While it may now seem obvious that certain chemical structures such as aromatic hydrocarbons or pyrazines have a certain cosmic “history”, it might cause more controversy to argue that chemical processes such as catalysis or polymerization also have their “histories”. -
Quantum Mechanics of Atoms and Molecules Lectures, the University of Manchester 2005
Quantum Mechanics of Atoms and Molecules Lectures, The University of Manchester 2005 Dr. T. Brandes April 29, 2005 CONTENTS I. Short Historical Introduction : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 1 I.1 Atoms and Molecules as a Concept . 1 I.2 Discovery of Atoms . 1 I.3 Theory of Atoms: Quantum Mechanics . 2 II. Some Revision, Fine-Structure of Atomic Spectra : : : : : : : : : : : : : : : : : : : : : 3 II.1 Hydrogen Atom (non-relativistic) . 3 II.2 A `Mini-Molecule': Perturbation Theory vs Non-Perturbative Bonding . 6 II.3 Hydrogen Atom: Fine Structure . 9 III. Introduction into Many-Particle Systems : : : : : : : : : : : : : : : : : : : : : : : : : 14 III.1 Indistinguishable Particles . 14 III.2 2-Fermion Systems . 18 III.3 Two-electron Atoms and Ions . 23 IV. The Hartree-Fock Method : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 24 IV.1 The Hartree Equations, Atoms, and the Periodic Table . 24 IV.2 Hamiltonian for N Fermions . 26 IV.3 Hartree-Fock Equations . 28 V. Molecules : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 35 V.1 Introduction . 35 V.2 The Born-Oppenheimer Approximation . 36 + V.3 The Hydrogen Molecule Ion H2 . 39 V.4 Hartree-Fock for Molecules . 45 VI. Time-Dependent Fields : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 48 VI.1 Time-Dependence in Quantum Mechanics . 48 VI.2 Time-dependent Hamiltonians . 50 VI.3 Time-Dependent Perturbation Theory . 53 VII.Interaction with Light : : : : : : : : : : : : : : : : : : : : : : : -
Chem3d 17.0 User Guide Chem3d 17.0
Chem3D 17.0 User Guide Chem3D 17.0 Table of Contents Recent Additions viii Chapter 1: About Chem3D 1 Additional computational engines 1 Serial numbers and technical support 3 About Chem3D Tutorials 3 Chapter 2: Chem3D Basics 5 Getting around 5 User interface preferences 9 Background settings 10 Sample files 10 Saving to Dropbox 10 Chapter 3: Basic Model Building 12 Default settings 12 Selecting a display mode 12 Using bond tools 13 Using the ChemDraw panel 15 Using other 2D drawing packages 15 Building from text 16 Adding fragments 18 Selecting atoms and bonds 18 Atom charges 21 Object position 23 Substructures 24 Refining models 27 Copying and printing 29 Finding structures online 32 Chapter 4: Displaying Models 35 © Copyright 1998-2017 PerkinElmer Informatics Inc., All rights reserved. ii Chem3D 17.0 Display modes 35 Atom and bond size 37 Displaying dot surfaces 38 Serial numbers 38 Displaying atoms 39 Atom symbols 40 Rotating models 41 Atom and bond properties 44 Showing hydrogen bonds 45 Hydrogens and lone pairs 46 Translating models 47 Scaling models 47 Aligning models 47 Applying color 49 Model Explorer 52 Measuring molecules 59 Comparing models by overlay 62 Molecular surfaces 63 Using stereo pairs 72 Stereo enhancement 72 Setting view focus 73 Chapter 5: Building Advanced Models 74 Dummy bonds and dummy atoms 74 Substructures 75 Bonding by proximity 78 Setting measurements 78 Atom and building types 81 Stereochemistry 85 © Copyright 1998-2017 PerkinElmer Informatics Inc., All rights reserved. iii Chem3D 17.0 Building with Cartesian -
RMG-Py and Cantherm Documentation ⇌Release 2.0.0
RMG RMG-Py and CanTherm Documentation ⇌Release 2.0.0 William H. Green, Richard H. West, and the RMG Team Sep 16, 2016 CONTENTS 1 RMG User’s Guide 3 1.1 Introduction...............................................3 1.2 Release Notes..............................................4 1.3 Overview of Features...........................................6 1.4 Installation................................................7 1.5 Creating Input Files........................................... 20 1.6 Example Input Files........................................... 29 1.7 Running a Job.............................................. 36 1.8 Analyzing the Output Files........................................ 37 1.9 Species Representation.......................................... 38 1.10 Group Representation.......................................... 39 1.11 Databases................................................. 39 1.12 Thermochemistry Estimation...................................... 58 1.13 Kinetics Estimation........................................... 63 1.14 Liquid Phase Systems.......................................... 65 1.15 Guidelines for Building a Model..................................... 72 1.16 Standalone Modules........................................... 73 1.17 Frequently Asked Questions....................................... 81 1.18 Credits.................................................. 82 1.19 How to Cite................................................ 82 2 CanTherm User’s Guide 83 2.1 Introduction..............................................