Journal ArticleDOI
Extending the molecular size in accurate quantum-chemical calculations: the equilibrium structure and spectroscopic properties of uracil
TLDR
It has been proved that the computational procedure presented is able to provide parameters with the proper accuracy to support experimental investigations of large molecules of biological interest.Abstract:
The equilibrium structure of uracil has been investigated using both theoretical and experimental data. With respect to the former, quantum-chemical calculations at the coupled-cluster level in conjunction with a triple-zeta basis set have been carried out. Extrapolation to the basis set limit, performed employing the second-order Moller–Plesset perturbation theory, and inclusion of core-correlation and diffuse-function corrections have also been considered. Based on the available rotational constants for various isotopic species together with corresponding computed vibrational corrections, the semi-experimental equilibrium structure of uracil has been determined for the first time. Theoretical and semi-experimental structures have been found in remarkably good agreement, thus pointing out the limitations of previous experimental determinations. Molecular and spectroscopic properties of uracil have then been studied by means of the composite computational approach introduced for the molecular structure evaluation. Among the results achieved, we mention the revision of the dipole moment. On the whole, it has been proved that the computational procedure presented is able to provide parameters with the proper accuracy to support experimental investigations of large molecules of biological interest.read more
Citations
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A new criterion for the determination of molecular structures from ground state rotational constants
TL;DR: In this article, it was shown that the effects of zero point vibrations are such that the coordinates obtained by substitution from the ground state moments of inertia I0 are systematically less than r0.
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Accuracy and Interpretability: The Devil and the Holy Grail. New Routes across Old Boundaries in Computational Spectroscopy.
TL;DR: This Review aims at being a comprehensive, authoritative, critical, and readable account of general interest to the chemistry community because of the wealth of qualitative and quantitative information that can be obtained from spectroscopic investigations.
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Implementation and validation of a multi-purpose virtual spectrometer for large systems in complex environments
Vincenzo Barone,Alberto Baiardi,Malgorzata Biczysko,Julien Bloino,Chiara Cappelli,Filippo Lipparini +5 more
TL;DR: This contribution summarises ongoing efforts in the research group toward the implementation and validation of a robust and user-friendly multi-frequency virtual spectrometer with special reference to the building blocks of biomolecules in their natural environment.
Journal ArticleDOI
Accurate structure, thermodynamic and spectroscopic parameters from CC and CC/DFT schemes: the challenge of the conformational equilibrium in glycine
TL;DR: The structures, relative stabilities, and infrared spectra of the six low-energy conformers of glycine have been characterized using a state-of-the-art quantum-mechanical approach allowing the bond distances, conformational enthalpies and vibrational frequencies to be determined well within the chemical accuracy.
Journal ArticleDOI
Accurate Characterization of the Peptide Linkage in the Gas Phase: A Joint Quantum-Chemical and Rotational Spectroscopy Study of the Glycine Dipeptide Analogue
Cristina Puzzarini,Malgorzata Biczysko,Vincenzo Barone,Laura Largo,Isabel Peña,Carlos Cabezas,José L. Alonso +6 more
TL;DR: An accurate characterization of the simplest dipeptide analogue (N-acetyl-glycinamide) involving peptidic bonds is presented, paving the route to the elucidation of the inherent behavior of peptides.
References
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Journal ArticleDOI
Gaussian basis sets for use in correlated molecular calculations. I. The atoms boron through neon and hydrogen
TL;DR: In this paper, a detailed study of correlation effects in the oxygen atom was conducted, and it was shown that primitive basis sets of primitive Gaussian functions effectively and efficiently describe correlation effects.
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Electron affinities of the first-row atoms revisited. Systematic basis sets and wave functions
TL;DR: In this paper, a reliable procedure for calculating the electron affinity of an atom and present results for hydrogen, boron, carbon, oxygen, and fluorine (hydrogen is included for completeness).
Journal ArticleDOI
Note on an Approximation Treatment for Many-Electron Systems
Chr. Møller,Milton S. Plesset +1 more
TL;DR: In this article, a perturbation theory for treating a system of n electrons in which the Hartree-Fock solution appears as the zero-order approximation was developed, and it was shown by this development that the first order correction for the energy and the charge density of the system is zero.
Journal ArticleDOI
A fifth-order perturbation comparison of electron correlation theories
TL;DR: In this paper, a new augmented version of coupled-cluster theory, denoted as CCSD(T), is proposed to remedy some of the deficiencies of previous augmented coupledcluster models.
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Basis-set convergence of correlated calculations on water
TL;DR: In this paper, the basis-set convergence of the electronic correlation energy in the water molecule is investigated at the second-order Mo/ller-Plesset level and at the coupled-cluster singles-and-doubles level with and without perturbative triples corrections applied.