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Lepetit C Chermette H Gicquel M Heully JL Chauvin R 《The journal of physical chemistry. A》2007,111(1):136-149
Mono- and polycyclic valence isomers of carbo-[3]oxocarbon C(9)O(3) and carbo-[5]oxocarbon C(15)O(5) have been characterized on the singlet spin state potential energy surface. By contrast to their geometry, their relative stability is highly sensitive to the calculation level. The performance of LDA, GGA, meta-GGA, and hybrid functionals is compared to that of HF, post-HF, and multiconfigurational calculations. The results obtained for C(9)O(3) are compared to those obtained for hydrocarbon analogues such as &[3]pericyclyne C9(H2)3 and carbo-[3]radialene C9(CH2)3 and are analyzed on the basis of an energy decomposition scheme. The respective role of the exchange and correlation counterparts of the functional in the discrepancy of the results is discussed. 相似文献
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Lebon E Bastin S Sutra P Vendier L Piau RE Dixon IM Boggio-Pasqua M Alary F Heully JL Igau A Juris A 《Chemical communications (Cambridge, England)》2012,48(5):741-743
Unexpected room temperature luminescence is observed and rationalized by highly challenging excited state calculations for a functionalized phosphine ligand coordinated on the [Ru(bpy)(tpy)](2+) core. 相似文献
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José Sánchez-Marín Ignacio Nebot-Gil Jean Paul Malrieu Jean Louis Heully Daniel Maynau 《Theoretical chemistry accounts》1996,95(5-6):215-241
Using the intermediate hamiltonian theory as a unique conceptual frame and the technique of CI matrix dressing, a wide series of single-reference methods for the treatment of the ground state correlation are reviewed, compared, and sometimes improved. These methods range from independent excitation approximation (the very next step beyond MP2) to coupled cluster, going through the so-called electron pair approximations and the (SC)2CI formalism. A hierarchy of these methods can be established according to two criteria:
- The physical effects incorporated in the model space, the choice of which is flexible.
- The quality of the evaluation of the coefficients of the external space determinants. This evaluation, which remains based on a single reference expansion of the wave function, may simply ensure the size consistency or incorporate the linked contributions from the outer space.
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Gicquel M Heully JL Lepetit C Chauvin R 《Physical chemistry chemical physics : PCCP》2008,10(24):3578-3589
Various isomers of carbo-[3]oxocarbon C9O3 have been characterized on the singlet and triplet spin state potential energy surfaces. Despite its localized structure, the ring carbo-mer of [3]oxocarbon is thermodynamically protected from subsequent isomerization and stable versus dissociation into C3O. It therefore appears as a reasonable synthetic target. In contrast, the less stable tetracyclic isomer exhibits electron delocalization both in the central six-membered ring and in the external three-membered rings, as evidenced from structural, magnetic and electron localization function (ELF) analysis. Another monocyclic isomer may be considered as a planar C6(CO)3 "carbon-complex", a carbon version of the related iron carbonyl complex Fe(PH3)2(CO)3. C6 and Fe(PH3)2 are indeed isolobal on the basis of frontier orbital analysis. 相似文献
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