Anharmonic force field from coupled-cluster methods and accurate computation of infrared spectra

Ermiş, Betül; Ünal, Aslı; Soydaş, Emine; Bozkaya, Uğur

doi:10.1016/bs.aiq.2021.05.003

Cited by 4 publications

(3 citation statements)

References 75 publications

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“…Finally, analytical force constants are not always available for all QC methods and computational packages. A well-known alternative strategy is based on the use of analytical gradients computed at the same geometries for performing the finite differences , f i j j = f i ( + δ q j ) + f i ( − δ q j ) − 2 f i ( boldq e q ) δ q j 2 and by the following expressions to estimate P i and P ii P i = bold-italicP ( + δ q i ) − bold-italicP ( − δ q i ) 2 δ q i P i i = bold-italicP ( + δ q i ) + bold-italicP ( − δ q i ) − 2 bold-italicP ( bold-italicq e q ) δ q i 2 …”

Section: Methodsmentioning

confidence: 99%

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Unbiased Comparison between Theoretical and Experimental Molecular Structures and Properties: Toward an Accurate Reduced-Cost Evaluation of Vibrational Contributions

Mendolicchio,

Barone

2024

J. Chem. Theory Comput.

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The tremendous development of hardware and software is constantly increasing the role of quantum chemical (QC) computations in the assignment and interpretation of experimental results. However, an unbiased comparison between theory and experiment requires the proper account of vibrational averaging effects. In particular, high-resolution spectra in the gas phase are now available for molecules containing up to about 50 atoms, which are too large for a brute-force approach with the available QC methods of sufficient accuracy. In the present paper, we introduce hybrid approaches, which allow the accurate evaluation of vibrational averaging effects for molecules of this size beyond the harmonic approximation, with special attention being devoted to rotational constants. After the validation of new tools for relatively small molecules, the β-estradiol hormone and a prototypical molecular motor have been considered to witness the feasibility of accurate computations for large molecules.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Unbiased Comparison between Theoretical and Experimental Molecular Structures and Properties: Toward an Accurate Reduced-Cost Evaluation of Vibrational Contributions

Mendolicchio,

Barone

2024

J. Chem. Theory Comput.

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“…Highly accurate predictions of anharmonic frequencies using correlated wave function methods are therefore limited to small molecules (<15 atoms). 17,19 Alternatively, the impact of anharmonicity on vibrational spectra can be examined by computing velocity autocorrelation functions from ab initio molecular dynamics (AIMD) simulations. However, AIMD is also computationally demanding and is not guaranteed to capture full anharmonic behavior.…”

Section: ■ Introductionmentioning

confidence: 99%

Recent Advances toward Efficient Calculation of Higher Nuclear Derivatives in Quantum Chemistry

et al. 2022

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In this paper, we provide an overview of state-of-the-art techniques that are being developed for efficient calculation of second and higher nuclear derivatives of quantum mechanical (QM) energy. Calculations of nuclear Hessians and anharmonic terms incur high costs and memory and scale poorly with system size. Three emerging classes of methodsmachine learning (ML), automatic differentiation (AD), and matrix completion (MC)have demonstrated promise in overcoming these challenges. We illustrate studies that employ unsupervised ML methods to reduce the need for multiple Hessian calculations in dynamics simulations and those that utilize supervised ML to construct approximate potential energy surfaces and estimate Hessians and anharmonic terms at reduced cost. By extension, if electronic structure operations could be written in a manner similar to functions underlying ML methods, rapid differentiation or AD routines can be employed to inexpensively calculate higher arbitrary-order derivatives. While ML approaches are typically black-box, we describe methods such as compressed sensing (CS) and MC, which explicitly leverage problem-specific mathematical properties of higher derivatives such as sparsity and low-rank, to complete higher derivative information using only a small, incomplete sample. The three classes of methods facilitate reliable predictions of observables ranging from infrared spectra to thermal conductivity and constitute a promising way forward in accurately capturing otherwise intractable higher-order responses of QM energy to nuclear perturbations.

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Accurate Vibrational and Ro-Vibrational Contributions to the Properties of Large Molecules by a New Engine Employing Curvilinear Internal Coordinates and Vibrational Perturbation Theory to Second Order

Mendolicchio,

Barone

2024

J. Chem. Theory Comput.

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Anharmonic force field from coupled-cluster methods and accurate computation of infrared spectra

Cited by 4 publications

References 75 publications

Unbiased Comparison between Theoretical and Experimental Molecular Structures and Properties: Toward an Accurate Reduced-Cost Evaluation of Vibrational Contributions

Unbiased Comparison between Theoretical and Experimental Molecular Structures and Properties: Toward an Accurate Reduced-Cost Evaluation of Vibrational Contributions

Recent Advances toward Efficient Calculation of Higher Nuclear Derivatives in Quantum Chemistry

Accurate Vibrational and Ro-Vibrational Contributions to the Properties of Large Molecules by a New Engine Employing Curvilinear Internal Coordinates and Vibrational Perturbation Theory to Second Order

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