The spectral properties of many-electron atomic Hamiltonians and the method of configuration interaction. I. Proof of convergence of the configuration interaction method

Choudhury, M. H.; Pearson, D. B.

doi:10.1063/1.524120

Cited by 5 publications

(2 citation statements)

References 4 publications

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“…tronegativity models. QEq models with fixed electronegativities are unable to account for changes in the tendency for an atom to attract or repel electrons with changes in the bonding environments [103,125]. In contrast, our ACE model has the capability to predict changes in atomic electronegativities based on different bonding environments, which leads to more realistic charge distributions.…”

Section: Uo2mentioning

confidence: 98%

Shadow molecular dynamics and atomic cluster expansions for flexible charge models

Goff¹,

Negre²,

Rohskopf³

et al. 2023

Preprint

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A shadow molecular dynamics scheme for flexible charge models is presented, where the shadow Born-Oppenheimer potential is derived from a coarse-grained approximation of range-separated density functional theory. The interatomic potential, including the atomic electronegativities and the charge-independent short-range part of the potential and force terms, are modeled by the linear atomic cluster expansion (ACE), which provides a computationally efficient alternative to many machine learning methods. The shadow molecular dynamics scheme is based on extended Lagrangian (XL) Born-Oppenheimer molecular dynamics (BOMD) [Eur. Phys. J. B 94, 164 ( 2021)]. XL-BOMD provides a stable dynamics, while avoiding the costly computational overhead associated with solving an all-to-all system of equations, which normally is required to determine the relaxed electronic ground state prior to each force evaluation. To demonstrate the proposed shadow molecular dynamics scheme for flexible charge models using the atomic cluster expansion, we emulate the dynamics generated from self-consistent charge density functional tight-binding (SCC-DFTB) theory using a second-order charge equilibration (QEq) model. The charge-independent potentials and electronegativities of the QEq model are trained for a supercell of uranium oxide (UO2) and a molecular system of liquid water. The combined ACE + XL-QEq dynamics are stable over a wide range of temperatures both for the oxide and the molecular systems, and provide a precise sampling of the Born-Oppenheimer potential energy surfaces. Accurate ground Coulomb energies are produced by the ACE-based electronegativity model during an NVE simulation of UO2, predicted to be within 1 meV of those from SCC-DFTB on average during comparable simulations.

show abstract

Section: Uo2mentioning

confidence: 98%

Shadow molecular dynamics and atomic cluster expansions for flexible charge models

Goff¹,

Negre²,

Rohskopf³

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…QEq models with fixed electronegativities are unable to account for changes in the tendency for an atom to attract or repel electrons with changes in the bonding environments. 106,126 In contrast, our ACE model has the capability to predict changes in atomic electronegativities based on different bonding environments, which leads to more realistic charge distributions.…”

Section: Vic Ace+xl-qeq Shadow Molecular Dynamicsmentioning

confidence: 99%

Shadow Molecular Dynamics and Atomic Cluster Expansions for Flexible Charge Models

Goff

Zhang

Negre

et al. 2023

J. Chem. Theory Comput.

View full text Add to dashboard Cite

A shadow molecular dynamics scheme for flexible charge models is presented where the shadow Born−Oppenheimer potential is derived from a coarse-grained approximation of rangeseparated density functional theory. The interatomic potential, including the atomic electronegativities and the charge-independent short-range part of the potential and force terms, is modeled by the linear atomic cluster expansion (ACE), which provides a computationally efficient alternative to many machine learning methods. The shadow molecular dynamics scheme is based on extended Lagrangian (XL) Born−Oppenheimer molecular dynamics (BOMD) [Eur. Phys. J. B 2021, 94, 164]. XL-BOMD provides stable dynamics while avoiding the costly computational overhead associated with solving an all-to-all system of equations, which normally is required to determine the relaxed electronic ground state prior to each force evaluation. To demonstrate the proposed shadow molecular dynamics scheme for flexible charge models using atomic cluster expansion, we emulate the dynamics generated from self-consistent charge density functional tight-binding (SCC-DFTB) theory using a second-order charge equilibration (QEq) model. The charge-independent potentials and electronegativities of the QEq model are trained for a supercell of uranium oxide (UO 2 ) and a molecular system of liquid water. The combined ACE+XL-QEq molecular dynamics simulations are stable over a wide range of temperatures both for the oxide and for the molecular systems and provide a precise sampling of the Born−Oppenheimer potential energy surfaces. Accurate ground Coulomb energies are produced by the ACE-based electronegativity model during an NVE simulation of UO 2 , predicted to be within 1 meV of those from SCC-DFTB on average during comparable simulations.

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Convergence of the Rayleigh—Ritz method in self-consistent-field and multiconfiguration self-consistent-field calculations

Fonte

1981

Theoret. Chim. Acta

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The spectral properties of many-electron atomic Hamiltonians and the method of configuration interaction. I. Proof of convergence of the configuration interaction method

Cited by 5 publications

References 4 publications

Shadow molecular dynamics and atomic cluster expansions for flexible charge models

Shadow molecular dynamics and atomic cluster expansions for flexible charge models

Shadow Molecular Dynamics and Atomic Cluster Expansions for Flexible Charge Models

Convergence of the Rayleigh—Ritz method in self-consistent-field and multiconfiguration self-consistent-field calculations

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