| 1. |
- Andersen, J. N., et al.
(författare)
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Differences in the Cs 4d and 5p surface and interface core-level shifts
- 1994
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Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614. ; 226:1-2, s. 106-110
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Tidskriftsartikel (refereegranskat)abstract
- Core-level binding energy shifts of Cs induced by changes in the surroundings of the Cs atoms are measured for two different Cs core levels, 5p and 4d, and are found to be different for these two levels. The surface core-level shift of Cs is found to differ by 25 meV between the two levels. In the case of the Cs core-level shifts between bulk Cs atoms and Cs atoms at an interface between Cs and an Al(111) surface the difference between the two levels is found to be as large as 60 meV. The implications of these results for the precision of the Z+1 approximation are discussed.
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| 2. |
- Erman, P, et al.
(författare)
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Autoionization Widths of the No Rydberg-valence State Complex In the 11-12 Ev Region
- 1995
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Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614. ; 239:1-3, s. 6-10
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Tidskriftsartikel (refereegranskat)abstract
- The photoion excitation spectra of (NO)-N-14 and (NO)-N-15 have been studied in the 105-112 Mn excitation region using high-order harmonic laser spectroscopy. Utilizing the small bandwidth offered by this technique, the natural widths of prominent lines in this region have been measured. These lines originate from interactions between high-lying Rydberg levels converging to the NO+ electronic ground state and a 'new' NO valence state situated close to the latter state. The present measurements show broad resonances corresponding to a decay time of 20-50 fs. This supports the interpretation that the decay takes place via rapid electronic autoionization.
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| 3. |
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| 4. |
- Joakim Persson, B., et al.
(författare)
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A theoretical investigation of the two lowest potential energy surfaces for the reaction C(3P)+NO (2Π)
- 1995
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Ingår i: Chemical Physics Letters. - 0009-2614. ; 234:4-6, s. 382-389
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Tidskriftsartikel (refereegranskat)abstract
- The two lowest potential energy surfaces for C(3P)+NO(2Π) have been investigated. The stationary points were first located using CASSCF gradient calculations and the geometries reoptimized using complete active space second-order perturbation theory. Zero-point corrections have been included in the energetics. In addition to the three linear conformations CNO, NCO and CON, a previously unreported triangular conformation has been found. We found no barrier to carbon attack to the oxygen end of NO, leading to CON. This channel would lead to direct production of N+CO but is expected to be entropically disfavoured. No barrier to CNO formation has been found, in accord with experimental predictions. Experimentalists found no evidence of CO production and concluded that CN+O are the main products, but our investigation gives no reason to exclude formation of N+CO. It is suggested that the discrepancy may be due to the fact that no monitoring of CO production was performed.
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| 5. |
- Klavins, J, et al.
(författare)
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Ionization In Collisions Between Excited Sodium Dimers and Atoms
- 1994
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Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614. ; 228:4-5, s. 346-350
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Tidskriftsartikel (refereegranskat)abstract
- Associative ionizing molecule-atom collisions Na-2(A(1) Sigma(u)(+)) + Na(3p) --> Na-3(+) + e have been observed at simultaneous excitation of dimers and atoms by means of two lasers. Measurements of the relevant ionization current show that the cross section of molecule-atom ionizing collisions exceeds by an order of magnitude the cross section of the well-known atom-atom associative ionization Na(3p) + Na(3p) --> Na-2(+) + e.
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| 6. |
- Nilsson, A., et al.
(författare)
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Photoabsorption and the unoccupied partial density of states of chemisorbed molecules
- 1992
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Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614. ; 197:1-2, s. 12-16
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Tidskriftsartikel (refereegranskat)abstract
- The 1s to 2π* resonances have been studied for CO strongly chemisorbed on Ni(100) and weakly chemisorbed on Cu(100) using high resolution X-ray absorption spectroscopy. We show that the spectra can be consistently described in terms of the local density of unoccupied 2π* electron states with the Fermi level obtained from corresponding X-ray photoelectron spectra. The core hole is demonstrated to induce large shifts in the unoccupied 2π* density of states.
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| 7. |
- Suenaga, K, et al.
(författare)
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Carbon nitride nanotubulite - densely-packed and well-aligned tubular nanostructures
- 1999
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Ingår i: Chemical Physics Letters. - 0009-2614. ; 300:5-6, s. 695-700
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Tidskriftsartikel (refereegranskat)abstract
- Tubular carbon nitride (CNx, x=0.01–0.32) nanoparticles were successfully synthesized by d.c. magnetron sputtering. These tubes were grown in a highly packed form perpendicularly on a sodium chloride substrate. Their number density is estimated to be ∼1×104 per μm2 and is constant over macroscopic regions. Sub-nanometer scale chemical mapping shows that the nitrogen to carbon atomic ratio is rather constant across these tubes. This successful synthesis of a nanotubulite – made of a rather compact aggregation of tubular nanoparticles – could facilitate experimental approaches to measure mechanical or electrical transport properties of such nanotubes and to open the way to variable nanotube applications.
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| 8. |
- Barnes, Leslie A, et al.
(författare)
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Symmetry breaking in O+4 : an application of the Brueckner coupled-cluster method
- 1994
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Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614 .- 1873-4448. ; 223:3, s. 207-214
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Tidskriftsartikel (refereegranskat)abstract
- A recent calculation of the antisymmetric stretch frequency for the rectangular structure of quartet O4+ using the QCISD(T) method gave a value of 3710 cin-1. This anomalous frequency is shown to be a consequence of symmetry-breaking effects, which occur even though the QCISD(T) solution derived from a delocalized SCF reference function lies energetically well below the two localized (symmetry-broken) solutions at the equilibrium geometry. The symmetry breaking is almost eliminated at the CCSD level of theory, but the small remaining symmetry-breaking effects are magnified at the CCSD (T) level of theory so that the antisymmetric stretch frequency is still significantly in error. The Brueckner coupled-cluster method, however, leads to a symmetrical solution which is free of symmetry-breaking effects, with an antisymmetric stretch frequency of 1322 cm-1, in good agreement with our earlier calculations using the CASSCF/CASSI method.
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| 9. |
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| 10. |
- Berggren, Magnus, et al.
(författare)
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Controlling inter-chain and intra-chain excitations of a poly(thiophene) derivative in thin films
- 1999
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Ingår i: Chemical Physics Letters. - : Elsevier. - 0009-2614 .- 1873-4448. ; 304:1-2, s. 84-90
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Tidskriftsartikel (refereegranskat)abstract
- The decay of photoexcitations in polythiophene chains has been studied in solid solutions of the polymer from room temperature to 4 K. A strong blue shift of the emission spectrum is observed in the polymer blend, as compared to the homopolymer. Dispersion of the polythiophene suppresses the non-radiative processes, which are suggested to be correlated to close contacts of polymer chains. Quantum chemistry modeling of the excited state distributed on two chains corroborate this conclusion.
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