Modern Quantum Chemistry with [Open]Molcas
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Correlation.Pdf
INTRODUCTION TO THE ELECTRONIC CORRELATION PROBLEM PAUL E.S. WORMER Institute of Theoretical Chemistry, University of Nijmegen, Toernooiveld, 6525 ED Nijmegen, The Netherlands Contents 1 Introduction 2 2 Rayleigh-SchrÄodinger perturbation theory 4 3 M¿ller-Plesset perturbation theory 7 4 Diagrammatic perturbation theory 9 5 Unlinked clusters 14 6 Convergence of MP perturbation theory 17 7 Second quantization 18 8 Coupled cluster Ansatz 21 9 Coupled cluster equations 26 9.1 Exact CC equations . 26 9.2 The CCD equations . 30 9.3 CC theory versus MP theory . 32 9.4 CCSD(T) . 33 A Hartree-Fock, Slater-Condon, Brillouin 34 B Exponential structure of the wavefunction 37 C Bibliography 40 1 1 Introduction These are notes for a six hour lecture series on the electronic correlation problem, given by the author at a Dutch national winterschool in 1999. The main purpose of this course was to give some theoretical background on the M¿ller-Plesset and coupled cluster methods. Both computational methods are available in many quantum chemical \black box" programs. The audi- ence consisted of graduate students, mostly with an undergraduate chemistry education and doing research in theoretical chemistry. A basic knowledge of quantum mechanics and quantum chemistry is pre- supposed. In particular a knowledge of Slater determinants, Slater-Condon rules and Hartree-Fock theory is a prerequisite of understanding the following notes. In Appendix A this theory is reviewed briefly. Because of time limitations hardly any proofs are given, the theory is sketchily outlined. No attempt is made to integrate out the spin, the theory is formulated in terms of spin-orbitals only. -
Effective Hamiltonians Derived from Equation-Of-Motion Coupled-Cluster
Effective Hamiltonians derived from equation-of-motion coupled-cluster wave-functions: Theory and application to the Hubbard and Heisenberg Hamiltonians Pavel Pokhilkoa and Anna I. Krylova a Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482 Effective Hamiltonians, which are commonly used for fitting experimental observ- ables, provide a coarse-grained representation of exact many-electron states obtained in quantum chemistry calculations; however, the mapping between the two is not triv- ial. In this contribution, we apply Bloch's formalism to equation-of-motion coupled- cluster (EOM-CC) wave functions to rigorously derive effective Hamiltonians in the Bloch's and des Cloizeaux's forms. We report the key equations and illustrate the theory by examples of systems with electronic states of covalent and ionic characters. We show that the Hubbard and Heisenberg Hamiltonians are extracted directly from the so-obtained effective Hamiltonians. By making quantitative connections between many-body states and simple models, the approach also facilitates the analysis of the correlated wave functions. Artifacts affecting the quality of electronic structure calculations such as spin contamination are also discussed. I. INTRODUCTION Coarse graining is commonly used in computational chemistry and physics. It is ex- ploited in a number of classic models serving as a foundation of modern solid-state physics: tight binding[1, 2], Drude{Sommerfeld's model[3{5], Hubbard's [6] and Heisenberg's[7{9] Hamiltonians. These models explain macroscopic properties of materials through effective interactions whose strengths are treated as model parameters. The values of these pa- rameters are determined either from more sophisticated theoretical models or by fitting to experimental observables. -
Electronic Supporting Information a New Class of Soluble and Stable Transition-Metal-Substituted Polyoxoniobates: [Cr2(OH)4Nb10o
Electronic Supplementary Material (ESI) for Dalton Transactions This journal is © The Royal Society of Chemistry 2012 Electronic Supporting Information A New Class of Soluble and Stable Transition-Metal-Substituted Polyoxoniobates: [Cr2(OH)4Nb10O30]8-. Jung-Ho Son, C. André Ohlin and William H. Casey* A) Computational Results The two most interesting aspects of this new polyoxoanion is the inclusion of a more redox active metal and the optical activity in the visible region. For these reasons we in particular wanted to explore whether it was possible to readily and routinely predict the location of the absorbance bands of this type of compound. Also, owing to the difficulty in isolating the oxidised and reduced forms of the central polyanion dichromate species, we employed computations at the density functional theory (DFT) level to get a better idea of the potential characteristics of these forms. Structures were optimised for anti-parallel and parallel electronic spin alignments, and for both high and low spin cases where relevant. Intermediate spin configurations were 8- II III also tested for [Cr2(OH)4Nb10O30] . As expected, the high spin form of the Cr Cr complex was favoured (Table S1, below). DFT overestimates the bond lengths in general, but gives a good picture of the general distortion of the octahedral chromium unit, and in agreement with the crystal structure predicts that the shortest bond is the Cr-µ2-O bond trans from the central µ6- oxygen in the Lindqvist unit, and that the (Nb-)µ2-O-Cr-µ4-O(-Nb,Nb,Cr) angle is smaller by ca 5˚ from the ideal 180˚. -
Computer-Assisted Catalyst Development Via Automated Modelling of Conformationally Complex Molecules
www.nature.com/scientificreports OPEN Computer‑assisted catalyst development via automated modelling of conformationally complex molecules: application to diphosphinoamine ligands Sibo Lin1*, Jenna C. Fromer2, Yagnaseni Ghosh1, Brian Hanna1, Mohamed Elanany3 & Wei Xu4 Simulation of conformationally complicated molecules requires multiple levels of theory to obtain accurate thermodynamics, requiring signifcant researcher time to implement. We automate this workfow using all open‑source code (XTBDFT) and apply it toward a practical challenge: diphosphinoamine (PNP) ligands used for ethylene tetramerization catalysis may isomerize (with deleterious efects) to iminobisphosphines (PPNs), and a computational method to evaluate PNP ligand candidates would save signifcant experimental efort. We use XTBDFT to calculate the thermodynamic stability of a wide range of conformationally complex PNP ligands against isomeriation to PPN (ΔGPPN), and establish a strong correlation between ΔGPPN and catalyst performance. Finally, we apply our method to screen novel PNP candidates, saving signifcant time by ruling out candidates with non‑trivial synthetic routes and poor expected catalytic performance. Quantum mechanical methods with high energy accuracy, such as density functional theory (DFT), can opti- mize molecular input structures to a nearby local minimum, but calculating accurate reaction thermodynamics requires fnding global minimum energy structures1,2. For simple molecules, expert intuition can identify a few minima to focus study on, but an alternative approach must be considered for more complex molecules or to eventually fulfl the dream of autonomous catalyst design 3,4: the potential energy surface must be frst surveyed with a computationally efcient method; then minima from this survey must be refned using slower, more accurate methods; fnally, for molecules possessing low-frequency vibrational modes, those modes need to be treated appropriately to obtain accurate thermodynamic energies 5–7. -
Dalton2018.0 – Lsdalton Program Manual
Dalton2018.0 – lsDalton Program Manual V. Bakken, A. Barnes, R. Bast, P. Baudin, S. Coriani, R. Di Remigio, K. Dundas, P. Ettenhuber, J. J. Eriksen, L. Frediani, D. Friese, B. Gao, T. Helgaker, S. Høst, I.-M. Høyvik, R. Izsák, B. Jansík, F. Jensen, P. Jørgensen, J. Kauczor, T. Kjærgaard, A. Krapp, K. Kristensen, C. Kumar, P. Merlot, C. Nygaard, J. Olsen, E. Rebolini, S. Reine, M. Ringholm, K. Ruud, V. Rybkin, P. Sałek, A. Teale, E. Tellgren, A. Thorvaldsen, L. Thøgersen, M. Watson, L. Wirz, and M. Ziolkowski Contents Preface iv I lsDalton Installation Guide 1 1 Installation of lsDalton 2 1.1 Installation instructions ............................. 2 1.2 Hardware/software supported .......................... 2 1.3 Source files .................................... 2 1.4 Installing the program using the Makefile ................... 3 1.5 The Makefile.config ................................ 5 1.5.1 Intel compiler ............................... 5 1.5.2 Gfortran/gcc compiler .......................... 9 1.5.3 Using 64-bit integers ........................... 12 1.5.4 Using Compressed-Sparse Row matrices ................ 13 II lsDalton User’s Guide 14 2 Getting started with lsDalton 15 2.1 The Molecule input file ............................ 16 2.1.1 BASIS ................................... 17 2.1.2 ATOMBASIS ............................... 18 2.1.3 User defined basis sets .......................... 19 2.2 The LSDALTON.INP file ............................ 21 3 Interfacing to lsDalton 24 3.1 The Grand Canonical Basis ........................... 24 3.2 Basisset and Ordering .............................. 24 3.3 Normalization ................................... 25 i CONTENTS ii 3.4 Matrix File Format ................................ 26 3.5 The lsDalton library bundle .......................... 27 III lsDalton Reference Manual 29 4 List of lsDalton keywords 30 4.1 **GENERAL ................................... 31 4.1.1 *TENSOR ............................... -
Quantum Chemistry on a Grid
Quantum Chemistry on a Grid Lucas Visscher Vrije Universiteit Amsterdam 1 Outline Why Quantum Chemistry needs to be gridified Computational Demands Other requirements What may be expected ? Program descriptions Dirac • Organization • Distributed development and testing Dalton Amsterdam Density Functional (ADF) An ADF-Dalton-Dirac grid driver Design criteria Current status Quantum Chemistry on the Grid, 08-11-2005 L. Visscher, Vrije Universiteit Amsterdam 2 Computational (Quantum) Chemistry QC is traditionally run on supercomputers Large fraction of the total supercomputer time annually allocated Characteristics Compute Time scales cubically or higher with number of atoms treated. Typical : a few hours to several days on a supercomputer Memory Usage scales quadratically or higher with number of atoms. Typical : A few hundred MB till tens of GB Data Storage variable. Typical: tens of Mb till hundreds of GB. Communication • Often serial (one-processor) runs in production work • Parallelization needs sufficient band width. Typical lower limit 100 Mb/s. Quantum Chemistry on the Grid, 08-11-2005 L. Visscher, Vrije Universiteit Amsterdam 3 Changing paradigms in quantum chemistry Computable molecules are often already “large” enough Many degrees of freedom Search for global minimum energy is less important Statistical sampling of different conformations is desired Let the nuclei move, follow molecules that evolve in time 2 steps : (Quantum) dynamics on PES 1 step : Classical dynamics with forces computed via QM Changing characteristics General: more similar calculations Compute time : Increases : more calculations Memory usage : Stays constant : typical size remains the same Data storage : Decreases : intermediate results are less important Communication: Decreases : only start-up data and final result Quantum Chemistry on the Grid, 08-11-2005 L. -
Computational Studies of the Unusual Water Adduct [Cp2time (OH2)]: the Roles of the Solvent and the Counterion
Dalton Transactions View Article Online PAPER View Journal | View Issue Computational studies of the unusual water + adduct [Cp2TiMe(OH2)] : the roles of the Cite this: Dalton Trans., 2014, 43, 11195 solvent and the counterion† Jörg Saßmannshausen + The recently reported cationic titanocene complex [Cp2TiMe(OH2)] was subjected to detailed computational studies using density functional theory (DFT). The calculated NMR spectra revealed the importance of including the anion and the solvent (CD2Cl2) in order to calculate spectra which were in good agreement Received 29th January 2014, with the experimental data. Specifically, two organic solvent molecules were required to coordinate to Accepted 19th March 2014 the two hydrogens of the bound OH2 in order to achieve such agreement. Further elaboration of the role DOI: 10.1039/c4dt00310a of the solvent led to Bader’s QTAIM and natural bond order calculations. The zirconocene complex + www.rsc.org/dalton [Cp2ZrMe(OH2)] was simulated for comparison. Creative Commons Attribution-NonCommercial 3.0 Unported Licence. Introduction Group 4 metallocenes have been the workhorse for a number of reactions for some decades now. In particular the cationic + compounds [Cp2MR] (M = Ti, Zr, Hf; R = Me, CH2Ph) are believed to be the active catalysts for a number of polymeriz- – ation reactions such as Kaminsky type α-olefin,1 10 11–15 16–18 This article is licensed under a carbocationic or ring-opening lactide polymerization. For these highly electrophilic cationic compounds, water is usually considered a poison as it leads to catalyst decompo- sition. In this respect it was quite surprising that Baird Open Access Article. Published on 21 March 2014. -
Kepler Gpus and NVIDIA's Life and Material Science
LIFE AND MATERIAL SCIENCES Mark Berger; [email protected] Founded 1993 Invented GPU 1999 – Computer Graphics Visual Computing, Supercomputing, Cloud & Mobile Computing NVIDIA - Core Technologies and Brands GPU Mobile Cloud ® ® GeForce Tegra GRID Quadro® , Tesla® Accelerated Computing Multi-core plus Many-cores GPU Accelerator CPU Optimized for Many Optimized for Parallel Tasks Serial Tasks 3-10X+ Comp Thruput 7X Memory Bandwidth 5x Energy Efficiency How GPU Acceleration Works Application Code Compute-Intensive Functions Rest of Sequential 5% of Code CPU Code GPU CPU + GPUs : Two Year Heart Beat 32 Volta Stacked DRAM 16 Maxwell Unified Virtual Memory 8 Kepler Dynamic Parallelism 4 Fermi 2 FP64 DP GFLOPS GFLOPS per DP Watt 1 Tesla 0.5 CUDA 2008 2010 2012 2014 Kepler Features Make GPU Coding Easier Hyper-Q Dynamic Parallelism Speedup Legacy MPI Apps Less Back-Forth, Simpler Code FERMI 1 Work Queue CPU Fermi GPU CPU Kepler GPU KEPLER 32 Concurrent Work Queues Developer Momentum Continues to Grow 100M 430M CUDA –Capable GPUs CUDA-Capable GPUs 150K 1.6M CUDA Downloads CUDA Downloads 1 50 Supercomputer Supercomputers 60 640 University Courses University Courses 4,000 37,000 Academic Papers Academic Papers 2008 2013 Explosive Growth of GPU Accelerated Apps # of Apps Top Scientific Apps 200 61% Increase Molecular AMBER LAMMPS CHARMM NAMD Dynamics GROMACS DL_POLY 150 Quantum QMCPACK Gaussian 40% Increase Quantum Espresso NWChem Chemistry GAMESS-US VASP CAM-SE 100 Climate & COSMO NIM GEOS-5 Weather WRF Chroma GTS 50 Physics Denovo ENZO GTC MILC ANSYS Mechanical ANSYS Fluent 0 CAE MSC Nastran OpenFOAM 2010 2011 2012 SIMULIA Abaqus LS-DYNA Accelerated, In Development NVIDIA GPU Life Science Focus Molecular Dynamics: All codes are available AMBER, CHARMM, DESMOND, DL_POLY, GROMACS, LAMMPS, NAMD Great multi-GPU performance GPU codes: ACEMD, HOOMD-Blue Focus: scaling to large numbers of GPUs Quantum Chemistry: key codes ported or optimizing Active GPU acceleration projects: VASP, NWChem, Gaussian, GAMESS, ABINIT, Quantum Espresso, BigDFT, CP2K, GPAW, etc. -
Modern Quantum Chemistry with [Open]Molcas
Modern quantum chemistry with [Open]Molcas Cite as: J. Chem. Phys. 152, 214117 (2020); https://doi.org/10.1063/5.0004835 Submitted: 17 February 2020 . Accepted: 11 May 2020 . Published Online: 05 June 2020 Francesco Aquilante , Jochen Autschbach , Alberto Baiardi , Stefano Battaglia , Veniamin A. Borin , Liviu F. Chibotaru , Irene Conti , Luca De Vico , Mickaël Delcey , Ignacio Fdez. Galván , Nicolas Ferré , Leon Freitag , Marco Garavelli , Xuejun Gong , Stefan Knecht , Ernst D. Larsson , Roland Lindh , Marcus Lundberg , Per Åke Malmqvist , Artur Nenov , Jesper Norell , Michael Odelius , Massimo Olivucci , Thomas B. Pedersen , Laura Pedraza-González , Quan M. Phung , Kristine Pierloot , Markus Reiher , Igor Schapiro , Javier Segarra-Martí , Francesco Segatta , Luis Seijo , Saumik Sen , Dumitru-Claudiu Sergentu , Christopher J. Stein , Liviu Ungur , Morgane Vacher , Alessio Valentini , and Valera Veryazov J. Chem. Phys. 152, 214117 (2020); https://doi.org/10.1063/5.0004835 152, 214117 © 2020 Author(s). The Journal ARTICLE of Chemical Physics scitation.org/journal/jcp Modern quantum chemistry with [Open]Molcas Cite as: J. Chem. Phys. 152, 214117 (2020); doi: 10.1063/5.0004835 Submitted: 17 February 2020 • Accepted: 11 May 2020 • Published Online: 5 June 2020 Francesco Aquilante,1,a) Jochen Autschbach,2,b) Alberto Baiardi,3,c) Stefano Battaglia,4,d) Veniamin A. Borin,5,e) Liviu F. Chibotaru,6,f) Irene Conti,7,g) Luca De Vico,8,h) Mickaël Delcey,9,i) Ignacio Fdez. Galván,4,j) Nicolas Ferré,10,k) Leon Freitag,3,l) Marco Garavelli,7,m) Xuejun Gong,11,n) Stefan Knecht,3,o) Ernst D. Larsson,12,p) Roland Lindh,4,q) Marcus Lundberg,9,r) Per Åke Malmqvist,12,s) Artur Nenov,7,t) Jesper Norell,13,u) Michael Odelius,13,v) Massimo Olivucci,8,14,w) Thomas B. -
Møller–Plesset Perturbation Theory: from Small Molecule Methods to Methods for Thousands of Atoms Dieter Cremer∗
Advanced Review Møller–Plesset perturbation theory: from small molecule methods to methods for thousands of atoms Dieter Cremer∗ The development of Møller–Plesset perturbation theory (MPPT) has seen four dif- ferent periods in almost 80 years. In the first 40 years (period 1), MPPT was largely ignored because the focus of quantum chemists was on variational methods. Af- ter the development of many-body perturbation theory by theoretical physicists in the 1950s and 1960s, a second 20-year long period started, during which MPn methods up to order n = 6 were developed and computer-programed. In the late 1980s and in the 1990s (period 3), shortcomings of MPPT became obvious, espe- cially the sometimes erratic or even divergent behavior of the MPn series. The physical usefulness of MPPT was questioned and it was suggested to abandon the theory. Since the 1990s (period 4), the focus of method development work has been almost exclusively on MP2. A wealth of techniques and approaches has been put forward to convert MP2 from a O(M5) computational problem into a low- order or linear-scaling task that can handle molecules with thousands of atoms. In addition, the accuracy of MP2 has been systematically improved by introducing spin scaling, dispersion corrections, orbital optimization, or explicit correlation. The coming years will see a continuously strong development in MPPT that will have an essential impact on other quantum chemical methods. C 2011 John Wiley & Sons, Ltd. WIREs Comput Mol Sci 2011 1 509–530 DOI: 10.1002/wcms.58 INTRODUCTION Hylleraas2 on the description of two-electron prob- erturbation theory has been used since the early lems with the help of perturbation theory. -
Arxiv:1911.06836V1 [Physics.Chem-Ph] 8 Aug 2019 A
Multireference electron correlation methods: Journeys along potential energy surfaces Jae Woo Park,1, ∗ Rachael Al-Saadon,2 Matthew K. MacLeod,3 Toru Shiozaki,2, 4 and Bess Vlaisavljevich5, y 1Department of Chemistry, Chungbuk National University, Chungdae-ro 1, Cheongju 28644, Korea. 2Department of Chemistry, Northwestern University, 2145 Sheridan Rd., Evanston, IL 60208, USA. 3Workday, 4900 Pearl Circle East, Suite 100, Boulder, CO 80301, USA. 4Quantum Simulation Technologies, Inc., 625 Massachusetts Ave., Cambridge, MA 02139, USA. 5Department of Chemistry, University of South Dakota, 414 E. Clark Street, Vermillion, SD 57069, USA. (Dated: November 19, 2019) Multireference electron correlation methods describe static and dynamical electron correlation in a balanced way, and therefore, can yield accurate and predictive results even when single-reference methods or multicon- figurational self-consistent field (MCSCF) theory fails. One of their most prominent applications in quantum chemistry is the exploration of potential energy surfaces (PES). This includes the optimization of molecular ge- ometries, such as equilibrium geometries and conical intersections, and on-the-fly photodynamics simulations; both depend heavily on the ability of the method to properly explore the PES. Since such applications require the nuclear gradients and derivative couplings, the availability of analytical nuclear gradients greatly improves the utility of quantum chemical methods. This review focuses on the developments and advances made in the past two decades. To motivate the readers, we first summarize the notable applications of multireference elec- tron correlation methods to mainstream chemistry, including geometry optimizations and on-the-fly dynamics. Subsequently, we review the analytical nuclear gradient and derivative coupling theories for these methods, and the software infrastructure that allows one to make use of these quantities in applications. -
Coupled Cluster Methods in Quantum Chemistry
Title: Coupled Cluster methods in quantum chemistry Name: Thorsten Rohwedder, Reinhold Schneider Al./Addr.: Technische UniversitatBerlin Coupled Cluster methods in quantum chemistry Short description Coupled Cluster methods applied in quantum chemistry reformulate the electronic Schrodinger equation as a nonlinear equation, enabling the computation of size- consistent high-precision approximations of the ground state solution for weakly cor- related systems. Introduction The Coupled Cluster method (CC method) is one of the most successful and frequently used approaches for the computation of atomic and molecular electronic structure, i.e. for the solution of the stationary electronic Schrodinger equation, whenever high ac- curacy is required. In contrast to Hartree-Fock type methods (HF) or methods from density functional theory (see the respective entries in this work), high accuracy meth- ods have to account in particular for the quantum-mechanical phenomenon of electronic correlation. If a preliminarily calculated reference solution { usually provided by a HF calculation { already is a good approximation to the sought ground state wave func- tion, the problem is said to be weakly correlated. CC as a post-Hartree-Fock method (also see the entry by M. Lewin) then enables an ecient, accurate and size-extensive description of solutions of the electronic Schrodingerequation. In this context, the 2 size-extensivity of the CC approach is a key aspect, re ecting the correct scaling of correlation energy with respect to the number of electrons. CC methods were initially developed for the treatment of many body quantum systems in nuclear physics in the 1950s and were used for quantum chemical calculations since the 1966 initial work by Paldus and Czek,see (Czek,1991) for a historical overview.