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41.
The late-3d transition-metal diatomic fluorides MF = FeF, CoF, NiF, and CuF have been studied using variational multireference (MRCI) and coupled-cluster [RCCSD(T)] methods, combined with large to very large basis sets. We examined a total of 35 (2S+1)|Lambda| states, constructing as well 29 full potential energy curves through the MRCI method. All examined states are ionic, diabatically correlating to M(+)+F(-)((1)S). Notwithstanding the "eccentric" character of the 3d transition metals and the difficulties to accurately be described with all-electron ab initio methods, our results are, in general, in very good agreement with available experimental numbers. 相似文献
42.
We construct configuration spaces for cyclic covers of the projective line that admit extra automorphisms and we describe the locus of curves with given automorphism group. As an application we provide examples of arbitrary high genus that are defined over their field of moduli and are not hyperelliptic. 相似文献
43.
Zdetsis AD 《The Journal of chemical physics》2011,134(9):094312
It is predicted by accurate density functional and coupled-cluster theory that planar [Si(5)C](2-) and [Si(5)C](1-) rings can be stabilized by flat pentacoordinate carbon-silicon bonds. The energy difference of the [Si(5)C](2-) dianion from the lowest energy three-dimensional isomer is about 12.2 kcal∕mol at the level of the density functional theory using the Becke 3-parameter (exchange), Lee, Yang and Parr functional, and the triple-ζ doubly polarized basis sets. Stable composite [Si(5)C](2) structures are formed either as nanowheels with axial C-C bonds of 1.51 A? or as isoenergetic pentagonal graphiticlike layers with double C-C distance (3.02 A?) and almost double aromaticity index, based on nucleus independent chemical shifts. Both of these structures are at least 12 kcal∕mol lower in energy than the lowest energy Si(10)C(2) structure reported in the literature, but about 5 kcal∕mol higher than the lowest energy structure found here. 相似文献
44.
Through a variety of highly correlated methods combined with large basis sets we have studied the electronic structure of FeO, FeO(+), and FeO(-). In particular, we have constructed complete potential energy curves for 48, 24, and 4 states for the FeO, FeO(+), and FeO(-) species, respectively, at the multireference level of theory. For all states examined we report energetics, common spectroscopic parameters, and dipole moments. Overall our results are in good agreement with experiment, but we have encountered as well interesting differences between experiment and theory deserving further investigation. 相似文献
45.
We derive the group structure for cyclotomic function fields obtained by applying the Carlitz action for extensions of an initial constant field. The tame and wild structures are isolated to describe the Galois action on differentials. We show that the associated invariant rings are not polynomial. 相似文献
46.
Nikolaos Chalmpes Dimitrios Moschovas Iosif Tantis Athanasios B. Bourlinos Aristides Bakandritsos Renia Fotiadou Michaela Patila Haralambos Stamatis Apostolos Avgeropoulos Michael A. Karakassides Dimitrios Gournis 《Molecules (Basel, Switzerland)》2021,26(6)
Hypergolic systems rely on organic fuel and a powerful oxidizer that spontaneously ignites upon contact without any external ignition source. Although their main utilization pertains to rocket fuels and propellants, it is only recently that hypergolics has been established from our group as a new general method for the synthesis of different morphologies of carbon nanostructures depending on the hypergolic pair (organic fuel-oxidizer). In search of new pairs, the hypergolic mixture described here contains polyaniline as the organic source of carbon and fuming nitric acid as strong oxidizer. Specifically, the two reagents react rapidly and spontaneously upon contact at ambient conditions to afford carbon nanosheets. Further liquid-phase exfoliation of the nanosheets in dimethylformamide results in dispersed single layers exhibiting strong Tyndall effect. The method can be extended to other conductive polymers, such as polythiophene and polypyrrole, leading to the formation of different type carbon nanostructures (e.g., photolumincent carbon dots). Apart from being a new synthesis pathway towards carbon nanomaterials and a new type of reaction for conductive polymers, the present hypergolic pairs also provide a novel set of rocket bipropellants based on conductive polymers. 相似文献
47.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option. 相似文献
48.
Aristides D. Zdetsis 《Physics letters. A》1979,71(4):367-369
It is shown that in phenomenological calculations, non-hermitian dynamical matrices can be formulated to be consistent with translational and other symmetry requirements. Such a formulation is proposed and discussed. 相似文献
49.
The ground state of the linear BNB molecule has been examined with multireference-based ab initio methods coupled with quantitative basis sets. Previous computational studies on BNB, even those using highly correlated single reference-based methods, e.g., the CCSD(T) and BDT methods, suggested that the two BN bond lengths were unequal. In this paper, the BN(X 3Pi) + B(2Pu) potential energy curve is constructed using a state-averaged multireference-based correlated method (SA-CASSCF+PT2). The four lowest states of BN were included in the state averaging procedure. These calculations reveal no symmetry breaking along the antisymmetric stretching mode of the molecule. 相似文献
50.
Aristides Christofides 《Journal of organometallic chemistry》1983,259(3):355-365
Bis(cycloocta-1,5-diene)platinum reacts with isopropyl isocyanide to give the trinuclear complex [Pt3(CNPri)6]. A related palladium compound was prepared by treating either [Pd(dba)2] or [Pd2(dba)2CHCl3] with 2,6-dimethylphenyl isocyanide. Reactions of the cluster [Pt3(CNC6H3-2,6-Me2)6] and its presumed palladium analogue with the olefins (NC)2C:C(CN)2, F2C:CFCl and (CN)2C:C(CF3)2, give the compounds [M(olefin)(CNC6H3-2,6-Me2)2] (M Pt, Pd) in which the metals are η2-bonded to the coordinated olefins. The compound [Pd3(CNC6H3-2,6-Me2)6] reacts with F2C:CFBr and with F2C:CFCl to give the trans complexes [Pd(X)(C2F3)(CNC6H3-2,6-Me2)2] (X Br, Cl). Similar compounds [M(L)-(CNC6H3-2,6-Me2)2] (M Pt, Pd), (L MeO2CHC:CHCO2Me, OOCH: CHCOO) have also been prepared, and characterised. Two platinum complexes [Pt(CH:NC6H3-2,6-Me2)(SiMePh2)(CNC6H3-2,6-Me2)2] and [Pt2(μ-(PhC)2CO)(CNC6H3-2,6-Me2) 4] hav been synthesized by treating the complex [Pt3(CNC6H3-2,6-Me2)6] with HSiMePh2 and cyclopropenone, respectively. NMR and IR data for the new species are reported and discussed. 相似文献