nanomaterials. design and simulation, 2007, p.329

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nanomaterials. design and simulation, 2007, p.329

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[...]... extended clusters and molecules were performed with the Gaussian 2003 program [23] The partial DOS, s p deg , and dt2g bands for the bulk catalysts are obtained and used to construct the self-energy matrices for Green’s function approach For the sake of consistency, both the discrete and continuous systems are calculated using the same method and basis sets The extended molecule and the bulk calculations... −121 081 44 −120 849 39 −121 658 62 −121 482 77 Table 6 Geometries and energies of PtH5 for doublet and quartet states Bond lengths and angles R1 R2 1 2 Energy (Ha) 2 4 1 560 2 792 90 0 120 0 −121 886 31 1 653 1 665 90 0 120 0 −121 994 74 Table 7 Geometries and energies of PtH6 for triplet and quintet states All bond lengths are the same and the angle between hydrogen–platinum–hydrogen is 90 Bond lengths... −123 852 47 2 28 −123 346 08 Table 10 Geometries and energies of PtH9 for doublet, quartet, and sextet states Bond lengths and angles 1–2, 1–3, 1–4 1–5, 1–6, 1–7, 1–8, 1–9, 1–10 Energy (Ha) 2 4 6 1 84 1 64 −124 298 34 2 07 2 28 −123 993 43 4 95 1 64 −124 127 34 Table 11 Geometries and energies of PtH10 for singlet, triplet, and quintet Bond lengths and angles 1–2, 1–3, 1–4, 1–5, 1–6, 1–7, 1–9, 1–10... 12 Geometries and energies of PtH11 for doublet and quartet states Bond lengths and angles 2 4 1–2 1–3, 1–5 1–4 1–6, 1–7, 1–8 1–9, 1–12 1–10, 1–11 1 86 1 92 3 45 1 86 1 70 1 92 1 62 2 08 5 17 1 62 2 05 2 08 Energy (Ha) −125 284 32 −125 366 80 The lowest energy of PtH5 PtH6 , and PtH7 correspond to multiplicities 4, 1, and 6, respectively The lowest energy singlet states of PtH8 PtH9 and PtH10 correspond... SDD basis set does not provide better results than the LANLDZ For the Pt trimer there is not a marked difference between the singlet and triplet states Using the LANDZ basis set the singlet and the triplets correspond to D3h and C2v point groups The bond lengths, angles, and energies of Pt 4 are shown in Table 2 The geometry is displayed in Figure 6 The SDD basis set provides lower energy values than... interfacing the molecule and a cluster of Bulk 2 atoms interfacing the molecule on another site 2; both clusters are followed by a semi-infinite bulk (Bulk 2 ) on the left, and a semi-infinite bulk material (Bulk 2 ), as shown in Figure 1 All the chemistry takes place at site M and the two bulk materials do not react with each other Partial DOS of the bulk materials represent the s p, and d band contributions... H21 H2C H22 ⎡ (3) The sub-matrices H11 , H22 , HCC , H12 (H21 ), H1C (HC1 ), and H2C (HC2 ) correspond to matrix elements of the left bulk and right bulk materials, the cluster, the coupling between the two bulk materials, the coupling between the cluster and left bulk, and 6 P B Balbuena et al the coupling between the cluster and right bulk, respectively Thus, the corresponding Green’s function is expressed... O, and OH Thus, in these cases (yellow and purple cases), even though there is a depletion of states (compared to pure Pt) in the range −5 to −7 eV, the DOS in that range shows a relatively high population which is attributed to the electronic states of the adsorbates In contrast, adsorption of H2 O and H2 O2 are much weaker, and those adsorbates do not contribute new states at energies between −7 and. .. shorter Pt–H distances are (a) (b) (c) (d) (e) (f) (g) (h) Figure 9 Structures of Pt7 Hm clusters: a and b Pt 7 H18 , c and d Pt 7 H12 , e Pt 7 H10 , f Pt 7 H9 , and g and h Pt7 H6 Electrical Characteristics of Bulk-Molecule Interfaces 17 Table 17 Geometry of Pt7 H6 with zero imaginary frequencies for singlet and quintet state Bond Length (Å) Pt1 –Pt2 Pt2 –Pt3 Pt1 –Pt3 Pt1 —H Pt2 —H 1 2 684 2 683 2 686 1... 20 Local DOS on the (a) tip and (b) center plane of an Si26 H32 cluster For each case the DOS on the central H, SiH, and Si are calculated DOS units are states/eV atom (a) (b) Figure 21 Structure of the benzene attached to the (a) center plane and (b) tip of a Si26 H32 cluster For each case the DOS at different distances of attachment were calculated and shown in Figures 22 and 23 . alt="" ⑦ 18 THEORETICAL AND COMPUTATIONAL CHEMISTRY Nanomaterials: Design and Simulation THEORETICAL AND COMPUTATIONAL CHEMISTRY SERIES EDITORS Professor P. Politzer Department of Chemistry University. prediction of physical and chemical properties in some cases impossible to be obtained experimentally, and in others providing an invaluable new instrument for guiding and interpreting experiments. This. 1. Fundamentals P. Schwerdtfeger (Editor) VOLUME 12 Energetic Materials, Part 1. Decomposition, Crystal and Molecular Properties P. Politzer and J.S. Murray (Editors) VOLUME 13 Energetic Materials, Part

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Mục lục

  • Front Cover

  • Title Page

  • Copyright Page

  • Table of Contents

  • Preface

  • Chapter 1 Electrical Characteristics of Bulk-Molecule Interfaces

    • 1. Introduction

    • 2. Computational Methods

    • 3. Adsorption of OOH, OH, O, H2O2 and H2O on a Platinum Surface

    • 4. Toward a Platinum Testbed

    • 5. Silicon Testbeds

    • Acknowledgements

    • References

    • Chapter 2 Structural Properties of Pure and Binary Nanoclusters Investigated by Computer Simulations

      • 1. Introduction

      • 2. Energetic Models

      • 3. Structures

      • 4. The Global Optimization of Pure and Binary Metallic Clusters

      • 5. Melting and Growth of Binary Metallic Clusters

      • 6. Conclusions

      • References

      • Chapter 3 Computer Simulation of the Solid–Liquid Phase Transition in Alkali Metal Nanoparticles

        • 1. Introduction

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