Analytical nuclear derivatives for the parametric two-electron reduced density matrix method

Valentine, Andrew J. S.; Mazziotti, David A.

doi:10.1016/j.cplett.2017.07.064

Cited by 5 publications

(1 citation statement)

References 38 publications

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“…The efficient computation of analytic energy gradients is now under intense development in RDM based methods [9][10][11][12][13][14]. In NOFT, the general formulation of analytic gradients was presented in Ref.…”

Section: Introductionmentioning

confidence: 99%

Analytic gradients for spin multiplets in natural orbital functional theory

Mitxelena

Piris

2020

The Journal of Chemical Physics

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Analytic energy gradients with respect to nuclear motion are derived for non-singlet compounds in the natural orbital functional theory. We exploit the formulation for multiplets in order to obtain a simple formula valid for any many-electron system in its ground mixed state with a total spin S and all possible spin projection Sz values. We demonstrate that the analytic gradients can be obtained without resorting to linear response theory or involving iterative procedures. It is required a single evaluation, so integral derivatives can be computed on-the-fly along the calculation and thus improve the effectiveness of screening by the Schwarz inequality. Results for small and medium size molecules with many spin multiplicities are shown. Our results are compared with experimental data and accurate theoretical equilibrium geometries.

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Section: Introductionmentioning

confidence: 99%

Analytic gradients for spin multiplets in natural orbital functional theory

Mitxelena

Piris

2020

The Journal of Chemical Physics

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Analytic second-order energy derivatives in natural orbital functional theory

Mitxelena

Piris

2018

J Math Chem

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The analytic energy gradients in the atomic orbital representation have recently been published (J. Chem. Phys. 146, 014102, 2017) within the framework of the natural orbital functional theory (NOFT). We provide here an alternative expression for them in terms of natural orbitals, and use it to derive the analytic second-order energy derivatives with respect to nuclear displacements in the NOFT. The computational burden is shifted to the calculation of perturbed natural orbitals and occupancies, since a set of linear coupled-perturbed equations obtained from the variational Euler equations must be solved to attain the analytic Hessian at the perturbed geometry. The linear response of both natural orbitals and occupation numbers to nuclear geometry displacements need only specify the reconstruction of the second-order reduced density matrix in terms of occupation numbers.

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Analytical nuclear derivatives for the parametric two-electron reduced density matrix method

Cited by 5 publications

References 38 publications

Analytic gradients for spin multiplets in natural orbital functional theory

Analytic gradients for spin multiplets in natural orbital functional theory

Analytic second-order energy derivatives in natural orbital functional theory

The Ag+ state falls below 3Ag
Taffet
¹
,
Scholes
²

2018
Chemical Physics
16
1
7
0
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Analytical nuclear derivatives for the parametric two-electron reduced density matrix method

Cited by 5 publications

References 38 publications

Analytic gradients for spin multiplets in natural orbital functional theory

Analytic gradients for spin multiplets in natural orbital functional theory

Analytic second-order energy derivatives in natural orbital functional theory

The Ag+ state falls below 3AgTaffet1, Scholes2 2018Chemical Physics16170View full textAdd to dashboardCite

Contact Info

Product

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About

The Ag+ state falls below 3Ag
Taffet
¹
,
Scholes
²

2018
Chemical Physics
16
1
7
0
View full text Add to dashboard Cite