A5079494932- Advanced Chemical Physics Studies
- Spectroscopy and Quantum Chemical Studies
- Quantum Computing Algorithms and Architecture
- Atmospheric Ozone and Climate
- Quantum and electron transport phenomena
- Quantum Information and Cryptography
- Quantum, superfluid, helium dynamics
- Photochemistry and Electron Transfer Studies
- Machine Learning in Materials Science
- Advanced NMR Techniques and Applications
- Catalysis and Oxidation Reactions
- Quantum many-body systems
- Inorganic Fluorides and Related Compounds
- Molecular spectroscopy and chirality
- Parallel Computing and Optimization Techniques
- Spectroscopy and Laser Applications
- Physics of Superconductivity and Magnetism
- Molecular Junctions and Nanostructures
- Scientific Computing and Data Management
- Distributed and Parallel Computing Systems
- Atomic and Molecular Physics
- Catalytic Processes in Materials Science
- Quantum Dots Synthesis And Properties
- Seismic Waves and Analysis
- Methane Hydrates and Related Phenomena
Pacific Northwest National Laboratory
2016-2025
Environmental Molecular Sciences Laboratory
2013-2024
Battelle
2013-2024
John Wiley & Sons (United States)
2013-2024
ETH Zurich
2006-2023
Microsoft (United States)
2023
Technical University of Munich
2009-2023
Microsoft (Switzerland)
2023
University of Washington
2020-2022
Wroclaw Medical University
2017-2021
A discussion of many the recently implemented features GAMESS (General Atomic and Molecular Electronic Structure System) LibCChem (the C++ CPU/GPU library associated with GAMESS) is presented. These include fragmentation methods such as fragment molecular orbital, effective potential orbital methods, hybrid MPI/OpenMP approaches to Hartree-Fock, resolution identity second order perturbation theory. Many new coupled cluster theory have been in GAMESS, multiple levels density functional/tight...
Specialized computational chemistry packages have permanently reshaped the landscape of chemical and materials science by providing tools to support guide experimental efforts for prediction atomistic electronic properties. In this regard, structure played a special role using first-principle-driven methodologies model complex processes. Over past few decades, rapid development computing technologies tremendous increase in power offered unique chance study transformations sophisticated...
This paper is the first in a series of papers on new approach to many-electron correlation problem, termed method moments coupled-cluster equations (MMCC). A hierarchy MMCC approximations, including renormalized and completely CCSD[T], CCSD(T), CCSD(TQ), CCSDT(Q) methods, which can be viewed as generalizations well-known perturbative CCSD(TQf), CCSDT(Qf) schemes, introduced. In this initial study, an emphasis placed ability describe bond breaking large effects due connected triples...
The single-reference ab initio methods for high accuracy calculations of potential energy surfaces (PESs) excited electronic states, termed the completely renormalized equation-of-motion coupled-cluster approaches with singles, doubles, and noniterative triples [CR-EOMCCSD(T)], are developed. In CR-EOMCCSD(T) methods, which based on formalism method moments equations, suitably designed corrections due to triple excitations added, in a state-selective manner, excited-state energies obtained...
The full version of the equation-of-motion coupled-cluster (EOMCC) method with all singles and doubles, a selected set triples defined through active orbitals (EOMCCSDt) has been implemented tested using H8, H2O, N2, C2, CH+ systems. It is demonstrated that EOMCCSDt provides results EOMCCSDT (EOMCC singles, triples) quality at fraction computer effort associated calculations. This includes excited states are dominated by doubles have large triexcited components. excellent performance...
The recently developed new approach to the many-electron correlation problem in atoms and molecules, termed method of moments coupled-cluster (CC) equations (MMCC), is reviewed. ground-state MMCC formalism its extension excited electronic states via equation-of-motion (EOMCC) are discussed. main principle all methods that non-iterative energy corrections which, when added ground- excited-state energies obtained standard CC calculations, such as CCSD or EOMCCSD, recover exact, full...
The recently proposed renormalized and completely CCSD(T) CCSD(TQ) methods, which can be viewed as generalizations of the noniterative perturbative CCSD(TQf) schemes result from more general method moments coupled-cluster equations, are applied to dissociation ground-state N2 molecule. It is shown that methods provide significantly better results for large N–N separations than their unrenormalized counterparts.
Several levels of theory, including both Gaussian-based and plane wave density functional theory (DFT), second-order perturbation (MP2), coupled cluster methods (CCSD(T)), are employed to study Au6 Au8 clusters. All predict that the lowest energy isomer is planar. For Au8, DFT two isomers In contrast, MP2 CCSD(T) be nonplanar.
The power of quantum chemistry to predict the ground and excited state properties complex chemical systems has driven development computational software, integrating advances in theory, applied mathematics, computer science. emergence new paradigms associated with exascale technologies also poses significant challenges that require a flexible forward strategy take full advantage existing forthcoming resources. In this context, sustainability interoperability software are among most pressing...
Abstract Elementary quantum mechanics proposes that a closed physical system consistently evolves in reversible manner. However, control and readout necessitate the coupling of to external environment, subjecting it relaxation decoherence. Consequently, system-environment interactions are indispensable for simulating physically significant theories. A broad spectrum systems condensed-matter high- energy physics, vibrational spectroscopy, circuit cavity QED necessitates incorporation bosonic...
The idea of selecting the most important higher-than-doubly excited configurations in single-reference coupled-cluster (CC) calculations for quasidegenerate ground states molecular systems through use active orbitals is extended to electronic via equation-of-motion (EOM) CC formalism. resulting EOMCCSDt method, which triexcited clusters T3 and corresponding three-body components EOMCC excitation operator R are restricted internal semiinternal defined orbitals, capable significantly improving...
The standard and renormalized coupled cluster methods with singles, doubles, noniterative triples their generalizations to excited states, based on the equation of motion approach, are applied 4He 16O nuclei. A comparison results exact diagonalization Hamiltonian in same model space shows that quantum chemistry inspired approximations provide an excellent description ground states bulk correlation effects is obtained at singles doubles level. Triples, treated noniteratively, virtually description.
Vertical excitation energies in uracil the gas phase and water solution are investigated by equation-of-motion coupled-cluster multireference configuration interaction methods. Basis set effects found to be important for converged results. The analysis of electronic wave functions reveals that lowest singlet states predominantly a singly excited character therefore well described single-reference methods augmented perturbative triples correction account dynamical correlation. Our best...
The low-lying excited states (La and Lb) of polyacenes from naphthalene to heptacene (N = 2-7) are studied using various time-dependent computational approaches. We perform high-level excited-state calculations equation motion coupled cluster with singles doubles (EOMCCSD) completely renormalized singles, doubles, perturbative triples (CR-EOMCCSD(T)) use these results evaluate the performance range-separated exchange-correlation functionals within linear-response (LR) real-time (RT) density...
Parallel hardware has become readily available to the computational chemistry research community. This perspective will review current state of parallel software utilizing high-performance computing platforms. Hardware and trends their effect on quantum methodologies, algorithms, development also be discussed.
The details of the graphical processing unit (GPU) implementation most computationally intensive (T)-part recently introduced regularized CCSD(T) (Reg-CCSD(T)) method [Kowalski, K.; Valiev, M.J. Chem. Phys. 2009, 131, 234107] for calculating electronic energies strongly correlated systems are discussed. Parallel tests performed several molecular show very good scalability triples part Reg-CCSD(T) approach. We also discuss performance GPU as a function parameters defining partitioning...
Criteria to assess charge-transfer (CT) and CT-like character of electronic excitations are examined. Time-dependent density functional theory (TDDFT) calculations with non-hybrid, hybrid, tuned long-range corrected (LC) functionals compared coupled-cluster (CC) benchmarks. The test set comprises an organic CT complex, two push-pull donor-acceptor chromophores, a cyanine dye, several polycyclic aromatic hydrocarbons. Proper is easily identified. Excitations significant changes upon...