| 1. |
- Estreicher, S.K., et al.
(författare)
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Stable and metastable states of C60H: buckminsterfullerene monohydride
- 1992
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Ingår i: Chemical Physics Letters. - 0009-2614 .- 1873-4448. ; 196:3-4, s. 311-316
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Tidskriftsartikel (refereegranskat)abstract
- Approximate ab initio Hartree-Fock and first-principles density functional calculations of potential energy surfaces and electronic structures of C60H show that the stable state has H attached to one C atom, outside the buckyball. This C atom is displaced radially outward and is close to being sp3 hybridized. The unpaired electron of C60H is delocalized. The calculated Fermi contact density at the proton is in good agreement with recent low-temperature μSR data. A metastable configuration has atomic H at the center of the ball (H@C60). Once trapped there, H must overcome a large barrier to go through the surface of C60. Other configurations we considered include H attached to one C atom but inside the buckyball, and H bridging one of the two inequivalent CC bonds. The barrier for diffusion of H from outside to the center of C60 have also been calculated. The results are compared to recent muon spin rotation studies in solid C60 and to the states of hydrogen in other forms of carbon.
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| 2. |
- Jones, R, et al.
(författare)
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Ab initio calculations of the structure and dynamics of C60 and C3- 60
- 1992
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Ingår i: Philosophical Magazine Letters. - : Informa UK Limited. - 0950-0839 .- 1362-3036. ; 65:6, s. 291-298
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Tidskriftsartikel (refereegranskat)abstract
- A local-density-functional cluster method is used to calculate the structure and vibrational modes of C60. We find C–C lengths in good agreement with observed values. The effect of doping the molecule with three extra electrons is investigated and shown to result in a surprising shortening of the longer bonds. The second derivatives of the energy are evaluated and have enabled, for the first time, all the normal modes of the molecule to be found. We find these to be in fair agreement with the available experimental results.
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| 3. |
- Jones, R., et al.
(författare)
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Theory of dislocations in GaAs
- 1994
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Ingår i: Proceedings of the 17th International Conference on Defects in Semiconductors. - : Trans Tech Publications Inc.. ; , s. 1605-1610
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Konferensbidrag (refereegranskat)
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| 4. |
- Stich, P., et al.
(författare)
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Structures of dislocations in GaAs and their modification by impurities
- 1994
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Ingår i: Physical Review B Condensed Matter. - 0163-1829 .- 1095-3795. ; 50, s. 17717-17720
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Tidskriftsartikel (refereegranskat)abstract
- Local density functional theory is used to show that both α and β dislocations in GaAs are reconstructed. This is done by relaxing large 158-atom H-terminated clusters of GaAs containing 90° partial dislocations. The reconstruction is strongly influenced by impurities: acceptor pairs destroy the reconstruction of β partials but strengthen it for α dislocations. Donors have opposite effects. The implication of these results for the pinning of dislocations in GaAs is discussed.
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