On the structure and vibrational frequencies of C20

Martin, Jan M. L.; El-Yazal, Jamal; François, J

doi:10.1016/0009-2614(95)01334-2

Cited by 79 publications

(59 citation statements)

References 30 publications

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“…Bond lengths of ns, nt, a-a, a-b, c-c, and b-c are shown in Fig. 1 [12][13][14][15][16][17][18][19][20][21] In neutral compounds, the HF and B3LYP geometries were almost the same as those reported previously using a similar basis set. 15,16 However, the relative energies of the cage with respect to the ground state of ring isomer were lower than those reported previously.…”

Section: Resultssupporting

confidence: 70%

“…[12][13][14][15][16][17][18][19][20][21] The stability of the different geometrical forms has been the center of a dispute that has lasted for many years. There is general consensus that there are three main candidates for the ground state structure: the cage, ring, and bowl isomers.…”

Section: Resultsmentioning

confidence: 99%

“…Theoretical methods provide a variety of relative energies. [12][13][14][15][16][17][18][19][20][21] Hartree-Fock Self Consistence Field (HF-SCF) calculations favor a ring structure. 12 Møller-Plesset second order perturbation theory (MP2) method with a small and large basis set favors a cage geometry 12 and bowl, respectively.…”

Section: Introductionmentioning

confidence: 99%

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Uptake Effects of Two Electrons for Relative Stability and Atomic Structures of Carbon Cluster Isomers of C₂₀: ab initio Methods

Lee¹,

Lee²,

Kang³

et al. 2009

Bulletin of the Korean Chemical Society

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This study examined the effect of the uptake of one and two electrons on the atomic structure of three isomers of C20 clusters, namely the ring, bowl (corannulene like), and cage (the smallest fullerene). Geometry optimizations were performed using the hybrid density functional (B3LYP) methods for neutral, singly and doubly charged C20, C20 -, and C20 2-. These results show that the symmetry of the lowest energies for ring and bowl isomers were not changed, whereas the increasing order of energy for the cage (the smallest fullerene) isomers was changed from D2h < C2h ≤ C2 of C20 through Ci < C2h < C2 < D2h of C20 -to Ci < C2 < D2h < C2h of C20 2-. The reduced symmetry isomers of the cage have comparative energy and the ground state symmetry of the neutral and single and double charged C20 decreased with increasing number of electrons taken up in the point of energetics. Interestingly, the difference in energy between the ground state and the next higher energy state of C20 2-was 3.5kcal/mol, which is the largest energy gap of the neutral, single anion and double anion of the cage isomers examined.Key Words: C 20 cluster isomers, Electron uptake effects, Atomic structures, Hybrid density functional (B3LYP) calculations BowlCage Ring Figure 1. Three classes of structures of C20 cluster isomers (Bowl, cage, and ring). Here a, b, c, and the numbers in bowl and cage isomers represent the specific atomic site, but ns and nt in ring the nominal single and triple bonds.

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Section: Resultssupporting

confidence: 70%

Section: Resultsmentioning

confidence: 99%

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Uptake Effects of Two Electrons for Relative Stability and Atomic Structures of Carbon Cluster Isomers of C₂₀: ab initio Methods

Lee¹,

Lee²,

Kang³

et al. 2009

Bulletin of the Korean Chemical Society

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“…18,19 C 20 has several isomers with approximately the same energies, [20][21][22][23][24][25][26] including the monocyclic ring, the corranulene-like bowl, and the fullerene cage.…”

Section: Introductionmentioning

confidence: 99%

Raman spectra and calculated vibrational frequencies of size-selected C16, C18, and C20 clusters

Ott

Rechtsteiner

Félix

et al. 1998

The Journal of Chemical Physics

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The surface plasmon polariton-enhanced Raman spectra of size-selected C 16 , C 18 , and C 20 clusters isolated in nitrogen matrices are presented along with the calculated vibrational frequencies for the ring and linear chain isomers. The Raman spectra, recorded at a range of excitation wavelengths from 457.9 to 670 nm, show strong resonance enhancement for the three clusters. The calculated vibrational frequencies for ring and linear chain isomers and the cage and bowl structures for C 20 are compared to the experimental frequencies. Systematic shifts in the series of peaks in the 200 cm Ϫ1 region for C 16 , C 18 , and C 20 suggest that the observed isomers have the same geometry, thereby ruling out the bowl and cage isomers for C 20 . The measured spectra appear to be most consistent with the linear chain isomer. This high-energy isomer may be produced during neutralization of the deposited cluster ions.

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“…Several recent studies have examined the minimum energy geometry of C 20 . 14,15 Since many of the interesting properties of fullerenes come from the addition or substitution of metal atoms, it was of great interest when a class of stable 20-atom molecular clusters ͑8 metal atoms and 12 carbon atoms, referred to as metallocarbohedrenes, or metcars͒ were reported. In particular, Guo and co-workers have reported the formation of M 8 C 12 , where MϭTi, V, Zr, Hf, Mo, or W, through the reaction of laser vaporized titanium with a variety of hydrocarbon gases.…”

Section: Characterization Of the Minimum Energy Structures Of Simentioning

confidence: 99%

Fast computation of analytical second derivatives with effective core potentials: Application to Si8C12, Ge8C12, and Sn8C12

Bode

Gordon

1999

The Journal of Chemical Physics

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An improved method is described for the computation of integrals involving effective core potentials. The improved method provides better scalability to higher angular momenta as well as improved speed. The new method is also applied to the determination of the minimum energy structures of Si8C12, Ge8C12, and Sn8C12, main group analogs of the Ti8C12compounds (known as metcars). Relative energies, geometries, and vibrational frequencies are reported for several novel structures. Keywords Elemental semiconductors, Germanium Disciplines Chemistry CommentsThe following article appeared in Journal of Chemical Physics 111 (1999): 8778, and may be found at doi:10.1063/1.480225. An improved method is described for the computation of integrals involving effective core potentials. The improved method provides better scalability to higher angular momenta as well as improved speed. The new method is also applied to the determination of the minimum energy structures of Si 8 C 12 , Ge 8 C 12 , and Sn 8 C 12 , main group analogs of the Ti 8 C 12 compounds ͑known as metcars͒. Relative energies, geometries, and vibrational frequencies are reported for several novel structures.

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On the structure and vibrational frequencies of C20

Cited by 79 publications

References 30 publications

Uptake Effects of Two Electrons for Relative Stability and Atomic Structures of Carbon Cluster Isomers of C₂₀: ab initio Methods

Uptake Effects of Two Electrons for Relative Stability and Atomic Structures of Carbon Cluster Isomers of C₂₀: ab initio Methods

Raman spectra and calculated vibrational frequencies of size-selected C16, C18, and C20 clusters

Fast computation of analytical second derivatives with effective core potentials: Application to Si8C12, Ge8C12, and Sn8C12

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On the structure and vibrational frequencies of C20

Cited by 79 publications

References 30 publications

Uptake Effects of Two Electrons for Relative Stability and Atomic Structures of Carbon Cluster Isomers of C20: ab initio Methods

Uptake Effects of Two Electrons for Relative Stability and Atomic Structures of Carbon Cluster Isomers of C20: ab initio Methods

Raman spectra and calculated vibrational frequencies of size-selected C16, C18, and C20 clusters

Fast computation of analytical second derivatives with effective core potentials: Application to Si8C12, Ge8C12, and Sn8C12

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Product

Resources

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Uptake Effects of Two Electrons for Relative Stability and Atomic Structures of Carbon Cluster Isomers of C₂₀: ab initio Methods

Uptake Effects of Two Electrons for Relative Stability and Atomic Structures of Carbon Cluster Isomers of C₂₀: ab initio Methods