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Shee J, Weber JL, Reichman DR, Friesner RA, Zhang S. On the potentially transformative role of auxiliary-field quantum Monte Carlo in quantum chemistry: A highly accurate method for transition metals and beyond. J Chem Phys 2023; 158:140901. [PMID: 37061483 PMCID: PMC10089686 DOI: 10.1063/5.0134009] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 02/01/2023] [Indexed: 04/17/2023] Open
Abstract
Approximate solutions to the ab initio electronic structure problem have been a focus of theoretical and computational chemistry research for much of the past century, with the goal of predicting relevant energy differences to within "chemical accuracy" (1 kcal/mol). For small organic molecules, or in general, for weakly correlated main group chemistry, a hierarchy of single-reference wave function methods has been rigorously established, spanning perturbation theory and the coupled cluster (CC) formalism. For these systems, CC with singles, doubles, and perturbative triples is known to achieve chemical accuracy, albeit at O(N7) computational cost. In addition, a hierarchy of density functional approximations of increasing formal sophistication, known as Jacob's ladder, has been shown to systematically reduce average errors over large datasets representing weakly correlated chemistry. However, the accuracy of such computational models is less clear in the increasingly important frontiers of chemical space including transition metals and f-block compounds, in which strong correlation can play an important role in reactivity. A stochastic method, phaseless auxiliary-field quantum Monte Carlo (ph-AFQMC), has been shown to be capable of producing chemically accurate predictions even for challenging molecular systems beyond the main group, with relatively low O(N3 - N4) cost and near-perfect parallel efficiency. Herein, we present our perspectives on the past, present, and future of the ph-AFQMC method. We focus on its potential in transition metal quantum chemistry to be a highly accurate, systematically improvable method that can reliably probe strongly correlated systems in biology and chemical catalysis and provide reference thermochemical values (for future development of density functionals or interatomic potentials) when experiments are either noisy or absent. Finally, we discuss the present limitations of the method and where we expect near-term development to be most fruitful.
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Affiliation(s)
- James Shee
- Kenneth S. Pitzer Center for Theoretical Chemistry, Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - John L. Weber
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, USA
| | - David R. Reichman
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, USA
| | - Richard A. Friesner
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, USA
| | - Shiwei Zhang
- Center for Computational Quantum Physics, Flatiron Institute, 162 5th Avenue, New York, New York 10010, USA
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2
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Eskridge B, Krakauer H, Shi H, Zhang S. Ab initio calculations in atoms, molecules, and solids, treating spin-orbit coupling and electron interaction on an equal footing. J Chem Phys 2022; 156:014107. [PMID: 34998316 DOI: 10.1063/5.0075900] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
We incorporate explicit, non-perturbative treatment of spin-orbit coupling into ab initio auxiliary-field quantum Monte Carlo (AFQMC) calculations. The approach allows a general computational framework for molecular and bulk systems in which material specificity, electron correlation, and spin-orbit coupling effects can be captured accurately and on an equal footing, with favorable computational scaling vs system size. We adopt relativistic effective-core potentials that have been obtained by fitting to fully relativistic data and that have demonstrated a high degree of reliability and transferability in molecular systems. This results in a two-component spin-coupled Hamiltonian, which is then treated by generalizing the ab initio AFQMC approach. We demonstrate the method by computing the electron affinity in Pb, the bond dissociation energy in Br2 and I2, and solid Bi.
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Affiliation(s)
- Brandon Eskridge
- Department of Physics, College of William and Mary, Williamsburg, Virginia 23187, USA
| | - Henry Krakauer
- Department of Physics, College of William and Mary, Williamsburg, Virginia 23187, USA
| | - Hao Shi
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
| | - Shiwei Zhang
- Center for Computational Quantum Physics, Flatiron Institute, New York, New York 10010, USA
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3
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Shen T, Liu Y, Yu Y, Rubenstein BM. Finite temperature auxiliary field quantum Monte Carlo in the canonical ensemble. J Chem Phys 2020; 153:204108. [DOI: 10.1063/5.0026606] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Tong Shen
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Yuan Liu
- Center for Ultracold Atoms, Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Yang Yu
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
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4
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Morales MA, Malone FD. Accelerating the convergence of auxiliary-field quantum Monte Carlo in solids with optimized Gaussian basis sets. J Chem Phys 2020; 153:194111. [DOI: 10.1063/5.0025390] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Miguel A. Morales
- Quantum Simulations Group, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Fionn D. Malone
- Quantum Simulations Group, Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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Malone FD, Zhang S, Morales MA. Accelerating Auxiliary-Field Quantum Monte Carlo Simulations of Solids with Graphical Processing Units. J Chem Theory Comput 2020; 16:4286-4297. [DOI: 10.1021/acs.jctc.0c00262] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Fionn D. Malone
- Quantum Simulations Group, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Shuai Zhang
- Quantum Simulations Group, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Miguel A. Morales
- Quantum Simulations Group, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
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6
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Kent PRC, Annaberdiyev A, Benali A, Bennett MC, Landinez Borda EJ, Doak P, Hao H, Jordan KD, Krogel JT, Kylänpää I, Lee J, Luo Y, Malone FD, Melton CA, Mitas L, Morales MA, Neuscamman E, Reboredo FA, Rubenstein B, Saritas K, Upadhyay S, Wang G, Zhang S, Zhao L. QMCPACK: Advances in the development, efficiency, and application of auxiliary field and real-space variational and diffusion quantum Monte Carlo. J Chem Phys 2020; 152:174105. [DOI: 10.1063/5.0004860] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Affiliation(s)
- P. R. C. Kent
- Center for Nanophase Materials Sciences Division and Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Abdulgani Annaberdiyev
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695-8202, USA
| | - Anouar Benali
- Computational Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Lemont, Illinois 60439, USA
| | - M. Chandler Bennett
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Edgar Josué Landinez Borda
- Quantum Simulations Group, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94551, USA
| | - Peter Doak
- Center for Nanophase Materials Sciences Division and Computational Sciences and Engineering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Hongxia Hao
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Kenneth D. Jordan
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | - Jaron T. Krogel
- Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
| | - Ilkka Kylänpää
- Computational Physics Laboratory, Tampere University, P.O. Box 692, 33014 Tampere, Finland
| | - Joonho Lee
- Department of Chemistry, Columbia University, New York, New York 10027, USA
| | - Ye Luo
- Computational Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Lemont, Illinois 60439, USA
| | - Fionn D. Malone
- Quantum Simulations Group, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94551, USA
| | - Cody A. Melton
- Sandia National Laboratories, Albuquerque, New Mexico 87123, USA
| | - Lubos Mitas
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695-8202, USA
| | - Miguel A. Morales
- Quantum Simulations Group, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94551, USA
| | - Eric Neuscamman
- Department of Chemistry, University of California, Berkeley, California 94720, USA
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Fernando A. Reboredo
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | - Brenda Rubenstein
- Department of Chemistry, Brown University, Providence, Rhode Island 02912, USA
| | - Kayahan Saritas
- Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA
| | - Shiv Upadhyay
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | - Guangming Wang
- Department of Physics, North Carolina State University, Raleigh, North Carolina 27695-8202, USA
| | - Shuai Zhang
- Laboratory for Laser Energetics, University of Rochester, 250 E River Rd., Rochester, New York 14623, USA
| | - Luning Zhao
- Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
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7
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Lee J, Malone FD, Morales MA. An auxiliary-Field quantum Monte Carlo perspective on the ground state of the dense uniform electron gas: An investigation with Hartree-Fock trial wavefunctions. J Chem Phys 2019. [DOI: 10.1063/1.5109572] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Joonho Lee
- College of Chemistry, University of California, Berkeley, California 94720, USA
| | - Fionn D. Malone
- Quantum Simulations Group, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94551, USA
| | - Miguel A. Morales
- Quantum Simulations Group, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94551, USA
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8
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Eskridge B, Krakauer H, Zhang S. Local Embedding and Effective Downfolding in the Auxiliary-Field Quantum Monte Carlo Method. J Chem Theory Comput 2019; 15:3949-3959. [DOI: 10.1021/acs.jctc.8b01244] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Brandon Eskridge
- Department of Physics, William & Mary, Williamsburg, Virginia 23187, United States
| | - Henry Krakauer
- Department of Physics, William & Mary, Williamsburg, Virginia 23187, United States
| | - Shiwei Zhang
- Department of Physics, William & Mary, Williamsburg, Virginia 23187, United States
- Center for Computational Quantum Physics, The Flatiron Institute, New York, New York 10010, United States
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9
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Mihm TN, McIsaac AR, Shepherd JJ. An optimized twist angle to find the twist-averaged correlation energy applied to the uniform electron gas. J Chem Phys 2019; 150:191101. [PMID: 31117769 DOI: 10.1063/1.5091445] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
We explore an alternative to twist averaging in order to obtain more cost-effective and accurate extrapolations to the thermodynamic limit (TDL) for coupled cluster doubles (CCD) calculations. We seek a single twist angle to perform calculations at, instead of integrating over many random points or a grid. We introduce the concept of connectivity, a quantity derived from the nonzero four-index integrals in an MP2 calculation. This allows us to find a special twist angle that provides appropriate connectivity in the energy equation, which yields results comparable to full twist averaging. This special twist angle effectively makes the finite electron number CCD calculation represent the TDL more accurately, reducing the cost of twist-averaged CCD over Ns twist angles from Ns CCD calculations to Ns MP2 calculations plus one CCD calculation.
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Affiliation(s)
- Tina N Mihm
- Department of Chemistry, University of Iowa, Iowa City, Iowa 52242-1002, USA
| | - Alexandra R McIsaac
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - James J Shepherd
- Department of Chemistry, University of Iowa, Iowa City, Iowa 52242-1002, USA
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10
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On Achieving High Accuracy in Quantum Chemical Calculations of 3d Transition Metal-Containing Systems: A Comparison of Auxiliary-Field Quantum Monte Carlo with Coupled Cluster, Density Functional Theory, and Experiment for Diatomic Molecules. J Chem Theory Comput 2019; 15:2346-2358. [DOI: 10.1021/acs.jctc.9b00083] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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11
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Landinez Borda EJ, Gomez J, Morales MA. Non-orthogonal multi-Slater determinant expansions in auxiliary field quantum Monte Carlo. J Chem Phys 2019; 150:074105. [DOI: 10.1063/1.5049143] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
| | - John Gomez
- Applied Physics Program and Department of Chemistry, Rice University, Houston, Texas 77005-1892, USA
| | - Miguel A. Morales
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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12
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Lee J, Small DW, Head-Gordon M. Open-shell coupled-cluster valence-bond theory augmented with an independent amplitude approximation for three-pair correlations: Application to a model oxygen-evolving complex and single molecular magnet. J Chem Phys 2018; 149:244121. [DOI: 10.1063/1.5052667] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Joonho Lee
- Department of Chemistry, University of California, Berkeley, California 94720, USA and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - David W. Small
- Department of Chemistry, University of California, Berkeley, California 94720, USA and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Martin Head-Gordon
- Department of Chemistry, University of California, Berkeley, California 94720, USA and Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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13
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Zhang S, Malone FD, Morales MA. Auxiliary-field quantum Monte Carlo calculations of the structural properties of nickel oxide. J Chem Phys 2018; 149:164102. [DOI: 10.1063/1.5040900] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Shuai Zhang
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Fionn D. Malone
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - Miguel A. Morales
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
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14
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Shee J, Arthur EJ, Zhang S, Reichman DR, Friesner RA. Phaseless Auxiliary-Field Quantum Monte Carlo on Graphical Processing Units. J Chem Theory Comput 2018; 14:4109-4121. [DOI: 10.1021/acs.jctc.8b00342] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- James Shee
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
| | - Evan J. Arthur
- Schrödinger
Inc., 120 West 45th Street, New York, New York 10036, United States
| | - Shiwei Zhang
- Department of Physics, College of William and Mary, Williamsburg, Virginia 23187-8795, United States
| | - David R. Reichman
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
| | - Richard A. Friesner
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
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15
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Ab initio computations of molecular systems by the auxiliary‐field quantum Monte Carlo method. WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE 2018. [DOI: 10.1002/wcms.1364] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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16
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Kim J, Baczewski AT, Beaudet TD, Benali A, Bennett MC, Berrill MA, Blunt NS, Borda EJL, Casula M, Ceperley DM, Chiesa S, Clark BK, Clay RC, Delaney KT, Dewing M, Esler KP, Hao H, Heinonen O, Kent PRC, Krogel JT, Kylänpää I, Li YW, Lopez MG, Luo Y, Malone FD, Martin RM, Mathuriya A, McMinis J, Melton CA, Mitas L, Morales MA, Neuscamman E, Parker WD, Pineda Flores SD, Romero NA, Rubenstein BM, Shea JAR, Shin H, Shulenburger L, Tillack AF, Townsend JP, Tubman NM, Van Der Goetz B, Vincent JE, Yang DC, Yang Y, Zhang S, Zhao L. QMCPACK: an open source ab initio quantum Monte Carlo package for the electronic structure of atoms, molecules and solids. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:195901. [PMID: 29582782 DOI: 10.1088/1361-648x/aab9c3] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
QMCPACK is an open source quantum Monte Carlo package for ab initio electronic structure calculations. It supports calculations of metallic and insulating solids, molecules, atoms, and some model Hamiltonians. Implemented real space quantum Monte Carlo algorithms include variational, diffusion, and reptation Monte Carlo. QMCPACK uses Slater-Jastrow type trial wavefunctions in conjunction with a sophisticated optimizer capable of optimizing tens of thousands of parameters. The orbital space auxiliary-field quantum Monte Carlo method is also implemented, enabling cross validation between different highly accurate methods. The code is specifically optimized for calculations with large numbers of electrons on the latest high performance computing architectures, including multicore central processing unit and graphical processing unit systems. We detail the program's capabilities, outline its structure, and give examples of its use in current research calculations. The package is available at http://qmcpack.org.
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Affiliation(s)
- Jeongnim Kim
- Intel Corporation, Hillsboro, OR 987124, United States of America
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Ranjan P, Chakraborty T, Kumar A. Computational Investigation of Cationic, Anionic and Neutral Ag2AuN (N = 1–7) Nanoalloy Clusters. PHYSICAL SCIENCES REVIEWS 2017. [DOI: 10.1515/psr-2016-0112] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractThe study of bimetallic nanoalloy clusters is of immense importance due to their diverse applications in the field of science and engineering. A deep theoretical insight is required to explain the physico-chemical properties of such compounds. Among such nanoalloy clusters, the compound formed between Ag and Au has received a lot of attention because of their marked electronic, catalytic, optical and magnetic properties. Density Functional Theory (DFT) is one of the most successful approaches of quantum mechanics to study the electronic properties of materials. Conceptual DFT-based descriptors have turned to be indispensable tools for analysing and correlating the experimental properties of compounds. In this report, we have investigated the ground state configurations and physico-chemical properties of Ag2AuNλ(N= 1–7,λ=±1, 0) nanoalloy clusters invoking DFT methodology. Our computed data exhibits interesting odd-even oscillation behaviour. A close agreement between experimental and our computed bond length supports our theoretical analysis.
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18
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Bonfim VS, Borges NM, Martins JBL, Gargano R, Politi JRDS. Quantum Monte Carlo with density matrix: potential energy curve derived properties. J Mol Model 2017; 23:104. [DOI: 10.1007/s00894-017-3272-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Accepted: 02/06/2017] [Indexed: 11/30/2022]
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Changlani HJ, Zheng H, Wagner LK. Density-matrix based determination of low-energy model Hamiltonians from ab initio wavefunctions. J Chem Phys 2015; 143:102814. [PMID: 26374007 DOI: 10.1063/1.4927664] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Affiliation(s)
- Hitesh J. Changlani
- Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green St., Urbana, Illinois 61801, USA
| | - Huihuo Zheng
- Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green St., Urbana, Illinois 61801, USA
| | - Lucas K. Wagner
- Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green St., Urbana, Illinois 61801, USA
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Purwanto W, Zhang S, Krakauer H. An auxiliary-field quantum Monte Carlo study of the chromium dimer. J Chem Phys 2015; 142:064302. [DOI: 10.1063/1.4906829] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Affiliation(s)
- Wirawan Purwanto
- Department of Physics, College of William and Mary, Williamsburg, Virginia 23187-8795, USA
| | - Shiwei Zhang
- Department of Physics, College of William and Mary, Williamsburg, Virginia 23187-8795, USA
| | - Henry Krakauer
- Department of Physics, College of William and Mary, Williamsburg, Virginia 23187-8795, USA
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Virgus Y, Purwanto W, Krakauer H, Zhang S. Stability, energetics, and magnetic states of cobalt adatoms on graphene. PHYSICAL REVIEW LETTERS 2014; 113:175502. [PMID: 25379922 DOI: 10.1103/physrevlett.113.175502] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Indexed: 06/04/2023]
Abstract
We investigate the stability and electronic properties of single Co atoms on graphene with near-exact many-body calculations. A frozen-orbital embedding scheme was combined with auxiliary-field quantum Monte Carlo calculations to increase the reach in system sizes. Several energy minima are found as a function of the distance h between Co and graphene. Energetics only permit the Co atom to occupy the top site at h=2.2 Å in a high-spin 3d(8)4s(1) state, and the van der Waals region at h=3.3 Å in a high-spin 3d(7)4s(2) state. The findings provide an explanation for recent experimental results with Co on free-standing graphene.
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Affiliation(s)
- Yudistira Virgus
- Department of Physics, College of William and Mary, Williamsburg, Virginia 23187-8795, USA
| | - Wirawan Purwanto
- Department of Physics, College of William and Mary, Williamsburg, Virginia 23187-8795, USA
| | - Henry Krakauer
- Department of Physics, College of William and Mary, Williamsburg, Virginia 23187-8795, USA
| | - Shiwei Zhang
- Department of Physics, College of William and Mary, Williamsburg, Virginia 23187-8795, USA
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