Journal ArticleDOI
Recent advances in multireference second order perturbation CI: The CIPSI method revisited
TLDR
The evolution of the CIPSI method, with the latest modifications recently implemented in our laboratory, is described in this paper, where a new version, based on a diagrammatic technique, is presented.Abstract:
The evolution of the CIPSI method, with the latest modifications recently implemented in our laboratory, is described. A new version, based on a diagrammatic technique, is presented. Test calculations which have been run on water, ethylene, and transacrolein, show that the new method is a powerful tool for the study of medium-size molecular systems.read more
Citations
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Quantum mechanical continuum solvation models.
TL;DR: This paper presents a meta-modelling procedure called "Continuum Methods within MD and MC Simulations 3072", which automates the very labor-intensive and therefore time-heavy and expensive process of integrating discrete and continuous components into a discrete-time model.
Journal ArticleDOI
Ultrafast Excited-State Dynamics in Nucleic Acids
TL;DR: The nature and dynamics of the singlet excited electronic states created in nucleic acids and their constituents by UV light are reviewed, finding that these states are highly stable to photochemical decay, perhaps as a result of selection pressure during a long period of molecular evolution.
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Quantum Mechanical Studies on the Photophysics and the Photochemistry of Nucleic Acids and Nucleobases
TL;DR: This review provides a concise, complete picture of the computational studies carried out, approximately, in the past decade on the photophysics of DNA nucleobases in the gas phase and in solution.
Journal ArticleDOI
Magnetic interactions in molecules and highly correlated materials: physical content, analytical derivation, and rigorous extraction of magnetic Hamiltonians.
TL;DR: Physical Content, Analytical Derivation, and Rigorous Extraction of Magnetic Hamiltonians Jean Paul Malrieu, Rosa Caballol, Carmen J. Calzado, Coen de Graaf, and Nathalie Guiheŕy.
Journal ArticleDOI
Advanced aspects of ab initio theoretical optical spectroscopy of transition metal complexes: Multiplets, spin-orbit coupling and resonance Raman intensities
TL;DR: In this paper, the authors present a review of the theoretical methods for the calculation of transition metal optical spectra with ab initio methods and discuss the treatment of dynamic correlation by using multireference (MR) many body perturbation theory in form of a second order correction to the CASSCF energy (CASPT2).
References
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Journal ArticleDOI
The iterative calculation of a few of the lowest eigenvalues and corresponding eigenvectors of large real-symmetric matrices
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Iterative perturbation calculations of ground and excited state energies from multiconfigurational zeroth‐order wavefunctions
TL;DR: In this article, the effect of configuration interaction by a Rayleigh-Schrodinger perturbation expansion when starting from a multiconfigurational wave function is calculated, and a barycentric defintion of H0 is proposed to ensure the cancellation of common diagrams in the calculated transition energies.
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Applicability of the multi-reference double-excitation CI (MRD-CI) method to the calculation of electronic wavefunctions and comparison with related techniques
TL;DR: In this article, a multi-reference double-excitation CI (MRD-CI) method is discussed and its results are compared with those of related techniques, which employs a configuration selection procedure to order the various generated species according to their energy-lowering capability and then uses an energy extrapolation procedure based on perturbation theory to obtain suitably accurate estimates of the eigenvalues of the entire MRD- CI space.
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Evaluation of molecular integrals over Gaussian basis functions
TL;DR: This method is computationally simple and numerically well behaved, and has been incorporated into a new molecular SCF program HONDO, and preliminary tests indicate that it is competitive with existing methods especially for highly angularly dependent functions.
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Convergence of an improved CIPSI algorithm
TL;DR: In this paper, the configuration interaction CIPSI algorithm defines three classes of determinants of decreasing importance; the most important ones are generators, the mean class (∼ 10 3 ) is treated variationally or to the fourth order.