Results 221 to 230 of about 71,384 (267)

Toward generalized tensor algebra for ab initio quantum chemistry methods

Proceedings of the 6th ACM SIGPLAN International Workshop on Libraries, Languages and Compilers for Array Programming, 2019
The widespread use of tensor operations in describing electronic structure calculations has motivated the design of software frameworks for productive development of scalable optimized tensor-based electronic structure methods. Whereas prior work focused on Cartesian abstractions for dense tensors, we present an algebra to specify and perform tensor ...
Erdal Mutlu, Karol Kowalski, Sriram Krishnamoorthy   +2 more
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Ab initio coupled cluster calculations for nuclei using methods of quantum chemistry

The European Physical Journal A, 2005
We report preliminary large scale ab initio calculations of ground and excited states of 16O using quantum chemistry inspired coupled cluster methods and realistic two-body interactions. By using the renormalized Hamiltonians obtained with a no-core G-matrix approach, we obtain the virtually converged results at the level of two-body interactions.
M. Włoch, D. J. Dean, J. R. Gour, P. Piecuch, M. Hjorth-Jensen, T. Papenbrock, K. Kowalski   +6 more
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Some Comparisons of Quantum Chemistry ab-initio Methods in Studying Peptide Bond Energy Variation

AIP Conference Proceedings, 2009
The peptide bond energy variation of methionine‐alanine dipeptide was calculated using HF, DFT and MP2 ab‐initio methods with 6‐31G and 6‐31++G** basis sets. The energy variation for MP2 method shows that as the distance between the two amino acid moieties is increased, the interaction energy between them decreases to negative infinity.
Hadieh Monajemi, Sharifuddin M. Zain, Wan Ahmad Tajuddin Wan Abdullah, Swee-Ping Chia, Kurunathan Ratnavelu, Muhamad Rasat Muhamad   +5 more
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Mathematical Models and Methods for Ab Initio Quantum Chemistry

2000
General topics: B. Sutcliffe: Is a molecule in chemistry explicable as a broken symmetry in quantum mechanics?- E. Cances: SCF algorithms for HF electronic calculations.- M. Caffarel, R. Assaraf: A pedagogical introduction to Quantum Monte-Carlo.- G. Turinici: On the controllability of bilinear quantum systems. Condensed phases: I. Catto, C. Le Bris, P-
Mireille Defranceschi, Claude Le Bris
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Quantum Chemistry: The Development ofab initioMethods in Molecular Electronic Structure Theory

Physics Bulletin, 1985
Henry F Schaefer III 1984 Clarendon Press: Oxford University Press xxiii + 144 pp price £15 ISBN 0 19 855183 5 This book was originally planned as a 'highly selective' collection of reprints tracing the development of ab initio methods in molecular electronic structure theory but, because of the limited space available, it was reduced to a brief ...
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Are ab initio quantum chemistry methods able to predict vibrational states up to the dissociation limit for multi-electron molecules close to spectroscopic accuracy?

Phys. Chem. Chem. Phys., 2011
The aim of the study was to explore the limits of ab initio methods towards the description of excited vibrational levels up to the dissociation limit for molecules having more than two electrons. To this end a high level ab initio potential energy function was constructed for the four-electron LiH molecule in order to accurately predict a complete set
Péter G, Szalay, Filip, Holka, Julien, Fremont, Michael, Rey, Kirk A, Peterson, Vladimir G, Tyuterev   +5 more
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The role of ab initio quantum chemistry and other theoretical methods in the understanding of protein conformations

Journal of Molecular Structure: THEOCHEM, 1995
Abstract For the determination of the conformation of a protein on the basis of its amino acid sequence extensive ab initio quantum chemical calculations on oligopeptides are first briefly described. From these computations determination of the secondary structure of polypeptide segments is expected.
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From Model Hamiltonians to ab Initio Hamiltonians and Back Again: Using Single Excitation Quantum Chemistry Methods To Find Multiexciton States in Singlet Fission Materials

Journal of Chemical Theory and Computation, 2016
Due to the promise of significantly enhanced photovoltaic efficiencies, significant effort has been directed toward understanding and controlling the singlet fission mechanism. Although accurate quantum chemical calculations would provide a detail-rich view of the singlet fission mechanism, this is complicated by the multiexcitonic nature of one of the
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A Miscellany of AB Initio Quantum Chemistry the Helium Atom Studied by Various Methods

1992
The aim of the following Problem is not to make the participants of this Institute experts of ab initio computational quantum chemistry (AICQC), but rather give them a ″flavour″ of this science.
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