Výsledky vyhledávání - "John M. Millam"

Density matrix search using direct inversion in the iterative subspace as a linear scaling alternative to diagonalization in electronic structure calculations

Autor: H. Bernhard Schlegel, John M. Millam, Michael J. Frisch, Xiaosong Li, Gustavo E. Scuseria

Publikováno v: The Journal of Chemical Physics. 119:7651-7658

For electronic structure calculations on large systems, solving the self-consistent-field (SCF) equations is one of the key bottlenecks. Density matrix search methods provide an efficient linear scaling approach for circumventing the traditional O(N3

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::9b63ab9295ea65ad3637bc05d33ba1a1
https://doi.org/10.1063/1.1607961

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Ab initio molecular dynamics: Propagating the density matrix with gaussian orbitals. IV. Formal analysis of the deviations from born-oppenheimer dynamics

Autor: Michael J. Frisch, Gustavo E. Scuseria, John M. Millam, H. Bernhard Schlegel, Srinivasan S. Iyengar, Gregory A. Voth

Publikováno v: Israel Journal of Chemistry. 42:191-202

In the context of the recently developed Atom-centered Density Matrix Propagation (ADMP) approach to ab initio molecular dynamics, a formal analysis of the deviations from the Born—Oppenheimer surface is conducted. These deviations depend on the fi

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::4adc837a312b1aa501c617057ea603a7
https://doi.org/10.1560/glw2-8nvq-4n6t-6c92

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Ab initio molecular dynamics: Propagating the density matrix with Gaussian orbitals. III. Comparison with Born–Oppenheimer dynamics

Autor: John M. Millam, Gregory A. Voth, Srinivasan S. Iyengar, Xiaosong Li, Michael J. Frisch, H. Bernhard Schlegel, Gustavo E. Scuseria

Publikováno v: The Journal of Chemical Physics. 117:8694-8704

In a recently developed approach to ab initio molecular dynamics (ADMP), we used an extended Lagrangian to propagate the density matrix in a basis of atom centered Gaussian functions. Results of trajectory calculations obtained by this method are com

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::e2ab3019075bd8ebef1c252c1fe9c84d
https://doi.org/10.1063/1.1514582

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An ab initio direct classical trajectory study of s-tetrazine photodissociation

Autor: Smriti Anand, Xiaosong Li, John M. Millam, H. Bernhard Schlegel

Publikováno v: Physical Chemistry Chemical Physics. 4:2554-2559

The photodissociation of s-tetrazine via a three-body fragmentation channel (C2N2H2→2HCN+N2) has been studied by ab initio direct classical trajectory calculations using Hartree–Fock and density functional methods with split valence and polarized

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::113b86c402728eaf26b6649f91e72e53
https://doi.org/10.1039/b111390a

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Glyoxal photodissociation. II. An ab initio direct classical trajectory study of C2H2O2→CO+H2CO

Autor: H. Bernhard Schlegel, John M. Millam, Xiaosong Li

Publikováno v: The Journal of Chemical Physics. 115:6907-6912

Photodissociation of glyoxal via the H2CO+CO channel has been investigated by ab initio classical trajectory calculations using Becke’s three-parameter hybrid functional method with split valence and polarized basis set [B3LYP/6-311G(d,p)]. To mode

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::5759870a72e4e136b29e7c3a7c126d56
https://doi.org/10.1063/1.1404141

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Ab initiomolecular dynamics: Propagating the density matrix with Gaussian orbitals

Autor: Srinivasan S. Iyengar, John M. Millam, Michael J. Frisch, H. Bernhard Schlegel, Gustavo E. Scuseria, Gregory A. Voth, Andrew D. Daniels

Publikováno v: The Journal of Chemical Physics. 114:9758-9763

We propose and implement an alternative approach to the original Car–Parrinello method where the density matrix elements (instead of the molecular orbitals) are propagated together with the nuclear degrees of freedom. Our new approach has the advan

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::752184a5dafd183d14faf12cd3479186
https://doi.org/10.1063/1.1372182

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Ab initio classical trajectories on the Born–Oppenheimer surface: Updating methods for Hessian-based integrators

Autor: Vebjørn Bakken, H. Bernhard Schlegel, John M. Millam

Publikováno v: The Journal of Chemical Physics. 111:8773-8777

For the integration of the classical equations of motion in the Born–Oppenheimer approach, each time the energy and gradient of the potential energy surface are needed, a properly converged wave function is calculated. If Hessians (second derivativ

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::556a20771516f54f0bad4acdbf1eb2aa
https://doi.org/10.1063/1.480224

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Ab initio classical trajectories on the Born–Oppenheimer surface: Hessian-based integrators using fifth-order polynomial and rational function fits

Autor: Wei Chen, H. Bernhard Schlegel, William L. Hase, John M. Millam, Vebjo, rn Bakken

Publikováno v: The Journal of Chemical Physics. 111:3800-3805

Classical trajectories can be computed directly from electronic structure calculations without constructing a global potential-energy surface. When the potential energy and its derivatives are needed during the integration of the classical equations

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::bab6ea9a9dc0d5c6b20c3e321408ad74
https://doi.org/10.1063/1.480037

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Linear scaling conjugate gradient density matrix search as an alternative to diagonalization for first principles electronic structure calculations

Autor: Gustavo E. Scuseria, John M. Millam

Publikováno v: The Journal of Chemical Physics. 106:5569-5577

Advances in the computation of the Coulomb, exchange, and correlation contributions to Gaussian-based Hartree–Fock and density functional theory Hamiltonians have demonstrated near-linear scaling with molecular size for these steps. These advances

Externí odkaz: https://explore.openaire.eu/search/publication?articleId=doi_________::b00faface3c8c61fa27a668b1766724d
https://doi.org/10.1063/1.473579

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