Molecular Oxygen Trimer: Multiplet Structures and Stability |
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Authors: | L Beatriz Castro-Gómez Dr José Campos-Martínez Dr Marta I Hernández Dr Ramón Hernández-Lamoneda |
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Institution: | 1. Centro de Investigaciones Químicas, Universidad Autónoma del Estado de Morelos, 62210 Cuernavaca, Morelos, Mexico;2. Instituto de Física Fundamental, Consejo, Superior de Investigaciones Científicas (IFF-CSIC), Serrano 123, 28006 Madrid, Spain |
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Abstract: | We present a detailed theoretical study of the molecular oxygen trimer where the potential energy surfaces of the seven multiplet states have been calculated by means of a pair approximation with very accurate dimer ab initio potentials. In order to obtain all the states a matrix representation of the potential using the uncoupled spin representation has been applied. The and states are nearly degenerate and low-lying isomers appear for most multiplicities. A crucial point in deciding the relative stabilities is the zero-point energy which represents a sizable fraction of the electronic well-depth. Therefore, we have performed accurate diffusion Monte Carlo studies of the lowest state in each multiplicity. Analysis of the wavefunction allows a deeper interpretation of the cluster structures, finding that they are significantly floppy in most cases. |
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Keywords: | van der Waals clusters Diffusion Monte Carlo Spin coupling ab initio potentials multiplet states |
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