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xiii | |
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1 Advances in Electronic Structure Methods for Defects and Impurities in Solids |
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1 | (16) |
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1 | (2) |
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1.2 Formalism and Computational Approach |
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3 | (3) |
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1.2.1 Defect Formation Energies and Concentrations |
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3 | (1) |
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1.2.2 Transition Levels or Ionization Energies |
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4 | (1) |
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5 | (1) |
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1.3 The DFT-LDA/GGA Band-Gap Problem and Possible Approaches to Overcome It |
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6 | (7) |
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1.3.1 LDA+U for Materials with Semicore States |
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6 | (3) |
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9 | (3) |
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1.3.3 Many-Body Perturbation Theory in the GW Approximation |
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12 | (1) |
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1.3.4 Modified Pseudopotentials |
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12 | (1) |
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13 | (4) |
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14 | (3) |
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2 Accuracy of Quantum Monte Carlo Methods for Point Defects in Solids |
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17 | (16) |
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17 | (1) |
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2.2 Quantum Monte Carlo Method |
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18 | (5) |
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2.2.1 Controlled Approximations |
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20 | (1) |
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20 | (1) |
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2.2.1.2 Configuration Population |
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20 | (1) |
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20 | (1) |
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21 | (1) |
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2.2.2 Uncontrolled Approximations |
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22 | (1) |
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2.2.2.1 Fixed-Node Approximation |
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22 | (1) |
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22 | (1) |
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2.2.2.3 Pseudopotential Locality |
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23 | (1) |
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2.3 Review of Previous DM C Defect Calculations |
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23 | (2) |
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23 | (2) |
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2.3.2 MgO Schottky Defect |
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25 | (1) |
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2.3.3 Si Interstitial Defects |
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25 | (1) |
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25 | (4) |
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26 | (1) |
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26 | (1) |
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2.4.3 Fixed-Node Approximation |
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26 | (3) |
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29 | (4) |
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29 | (4) |
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3 Electronic Properties of Interfaces and Defects from Many-body Perturbation Theory. Recent Developments and Applications |
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33 | (28) |
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33 | (1) |
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3.2 Many-Body Perturbation Theory |
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34 | (4) |
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34 | (2) |
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36 | (1) |
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3.2.3 Beyond the GW Approximation |
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37 | (1) |
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3.3 Practical Implementation of GW and Recent Developments Beyond |
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38 | (10) |
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3.3.1 Perturbative Approach |
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38 | (2) |
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3.3.2 QP Self-Consistent GW |
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40 | (1) |
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3.3.3 Plasmon Pole Models Versus Direct Calculation of the Frequency Integral |
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41 | (3) |
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3.3.4 The Extrapolar Method |
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44 | (1) |
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3.3.4.1 Polarizability with a Limited Number of Empty States |
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45 | (1) |
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3.3.4.2 Self-Energy with a Limited Number of Empty States |
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46 | (1) |
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3.3.5 MBPT in the PAW Framework |
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46 | (2) |
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3.4 QP Corrections to the BOs at Interfaces |
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48 | (6) |
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3.5 QP Corrections for Defects |
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54 | (3) |
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3.6 Conclusions and Prospects |
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57 | (4) |
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58 | (3) |
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4 Accelerating GW Calculations with Optimal Polarizability Basis |
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61 | (18) |
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61 | (1) |
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62 | (2) |
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4.3 The Method: Optimal Polarizability Basis |
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64 | (4) |
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4.4 Implementation and Validation |
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68 | (4) |
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69 | (1) |
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70 | (1) |
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70 | (2) |
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4.5 Example: Point Defects in a-Si3N4 |
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72 | (5) |
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72 | (1) |
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73 | (1) |
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4.5.3 Electronic Structure |
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74 | (3) |
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77 | (2) |
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77 | (2) |
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5 Calculation of Semiconductor Band Structures and Defects by the Screened Exchange Density Functional |
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79 | (18) |
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79 | (1) |
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5.2 Screened Exchange Functional |
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80 | (2) |
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5.3 Bulk Band Structures and Defects |
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82 | (11) |
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5.3.1 Band Structure of ZnO |
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83 | (2) |
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85 | (4) |
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5.3.3 Band Structure of MgO |
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89 | (1) |
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5.3.4 Band Structures of SnO2 and CdO |
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90 | (1) |
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5.3.5 Band Structure and Defects of HfO2 |
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91 | (1) |
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92 | (1) |
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93 | (4) |
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94 | (3) |
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6 Accurate Treatment of Solids with the HSE Screened Hybrid |
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97 | (14) |
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6.1 Introduction and Basics of Density Functional Theory |
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97 | (3) |
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100 | (3) |
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103 | (1) |
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104 | (3) |
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107 | (4) |
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108 | (3) |
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7 Defect Levels Through Hybrid Density Functionals: Insights and Applications |
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111 | (28) |
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111 | (1) |
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7.2 Computational Toolbox |
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112 | (5) |
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7.2.1 Defect Formation Energies and Charge Transition Levels |
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113 | (1) |
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7.2.2 Hybrid Density Functionals |
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114 | (1) |
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7.2.2.1 Integrable Divergence |
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115 | (2) |
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7.3 General Results from Hybrid Functional Calculations |
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117 | (8) |
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7.3.1 Alignment of Bulk Band Structures |
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118 | (2) |
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7.3.2 Alignment of Defect Levels |
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120 | (2) |
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7.3.3 Effect of Alignment on Defect Formation Energies |
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122 | (2) |
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7.3.4 "The Band-Edge Problem" |
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124 | (1) |
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7.4 Hybrid Functionals with Empirically Adjusted Parameters |
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125 | (4) |
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7.5 Representative Case Studies |
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129 | (3) |
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129 | (2) |
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7.5.2 Charge State of O2 During Silicon Oxidation |
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131 | (1) |
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132 | (7) |
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134 | (5) |
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8 Accurate Gap Levels and Their Role in the Reliability of Other Calculated Defect Properties |
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139 | (16) |
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139 | (2) |
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8.2 Empirical Correction Schemes for the KS Levels |
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141 | (2) |
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8.3 The Role of the Gap Level Positions in the Relative Energies of Various Defect Configurations |
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143 | (3) |
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8.4 Correction of the Total Energy Based on the Corrected Gap Level Positions |
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146 | (2) |
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8.5 Accurate Gap Levels and Total Energy Differences by Screened Hybrid Functionals |
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148 | (3) |
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151 | (4) |
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152 | (3) |
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9 LDA + U and Hybrid Functional Calculations for Defects in ZnO, SnO2, and TiOz |
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155 | (10) |
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155 | (1) |
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156 | (7) |
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158 | (2) |
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160 | (1) |
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161 | (2) |
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163 | (2) |
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163 | (2) |
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10 Critical Evaluation of the LDA + U Approach for Band Gap Corrections in Point Defect Calculations: The Oxygen Vacancy in ZnO Case Study |
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165 | (18) |
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165 | (1) |
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166 | (2) |
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10.3 LDA + L7 Band Structures Compared to GW |
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168 | (2) |
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10.4 Improved LDA + U Model |
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170 | (2) |
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10.5 Finite Size Corrections |
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172 | (1) |
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173 | (1) |
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10.7 Results for New LDA + U |
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174 | (2) |
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10.8 Comparison with Other Results |
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176 | (2) |
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10.9 Discussion of Experimental Results |
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178 | (1) |
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179 | (4) |
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180 | (3) |
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11 Predicting Polaronic Defect States by Means of Generalized Koopmans Density Functional Calculations |
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183 | (18) |
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183 | (2) |
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11.2 The Generalized Koopmans Condition |
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185 | (2) |
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11.3 Adjusting the Koopmans Condition using Parameterized On-Site Functionals |
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187 | (2) |
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11.4 Koopmans Behavior in Hybrid-functionals: The Nitrogen Acceptor in ZnO |
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189 | (4) |
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11.5 The Balance Between Localization and Delocalization |
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193 | (3) |
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196 | (5) |
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197 | (4) |
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12 SiO2 in Density Functional Theory and Beyond |
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201 | (12) |
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201 | (1) |
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12.2 The Band Gap Problem |
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202 | (2) |
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204 | (3) |
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207 | (2) |
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209 | (4) |
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210 | (3) |
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13 Overcoming Bipolar Doping Difficulty in Wide Gap Semiconductors |
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213 | (28) |
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213 | (1) |
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13.2 Method of Calculation |
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214 | (3) |
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13.3 Symmetry and Occupation of Defect Levels |
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217 | (1) |
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13.4 Origins of Doping Difficulty and the Doping Limit Rule |
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218 | (2) |
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13.5 Approaches to Overcome the Doping Limit |
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220 | (17) |
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13.5.1 Optimization of Chemical Potentials |
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220 | (1) |
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13.5.1.1 Chemical Potential of Host Elements |
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220 | (2) |
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13.5.1.2 Chemical Potential of Dopant Sources |
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222 | (1) |
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223 | (1) |
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13.5.3 Surfactant Enhanced Doping |
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224 | (2) |
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13.5.4 Appropriate Selection of Dopants |
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226 | (3) |
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13.5.5 Reduction of Transition Energy Levels |
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229 | (3) |
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13.5.6 Universal Approaches Through Impurity-Band Doping |
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232 | (5) |
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237 | (4) |
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238 | (3) |
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14 Electrostatic Interactions between Charged Defects in Supercelis |
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241 | (18) |
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241 | (2) |
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14.2 Electrostatics in Real Materials |
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243 | (7) |
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14.2.1 Potential-based Formulation of Electrostatics |
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245 | (1) |
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14.2.2 Derivation of the Correction Scheme |
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246 | (3) |
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14.2.3 Dielectric Constants |
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249 | (1) |
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250 | (4) |
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14.3.1 Ga Vacancy in GaAs |
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250 | (2) |
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14.3.2 Vacancy in Diamond |
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252 | (2) |
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254 | (5) |
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257 | (2) |
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15 Formation Energies of Point Defects at Finite Temperatures |
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259 | (26) |
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259 | (2) |
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261 | (17) |
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15.2.1 Analysis of Approaches to Correct for the Spurious Elastic Interaction in a Supercell Approach |
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261 | (1) |
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15.2.1.1 The Volume Optimized Aapproach to Point Defect Properties |
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262 | (2) |
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15.2.1.2 Derivation of the Constant Pressure and Rescaled Volume Approach |
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264 | (2) |
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15.2.2 Electronic, Quasiharmonic, and Anharmonic Contributions to the Formation Free Energy |
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266 | (1) |
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15.2.2.1 Free Energy Born--Oppenheimer Approximation |
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266 | (3) |
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15.2.2.2 Electronic Excitations |
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269 | (2) |
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15.2.2.3 Quasiharmonic Atomic Excitations |
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271 | (1) |
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15.2.2.4 Anharmonic Atomic Excitations: Thermodynamic Integration |
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272 | (2) |
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15.2.2.5 Anharmonic Atomic Excitations: Beyond the Thermodynamic Integration |
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274 | (4) |
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15.3 Results: Electronic, Quasiharmonic, and Anharmonic Excitations in Vacancy Properties |
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278 | (4) |
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282 | (3) |
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282 | (3) |
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16 Accurate Kohn--Sham DFT With the Speed of Tight Binding: Current Techniques and Future Directions in Materials Modelling |
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285 | (20) |
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285 | (1) |
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16.2 The AIMPRO Kohn--Sham Kernel: Methods and Implementation |
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286 | (4) |
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16.2.1 Gaussian-Type Orbitals |
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286 | (2) |
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288 | (1) |
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16.2.3 The Energy Kernel: Parallel Diagonalisarion and Iterative Methods |
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288 | (1) |
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16.2.4 Forces and Structural Relaxation |
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289 | (1) |
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289 | (1) |
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290 | (2) |
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16.3.1 Energetics: Equilibrium and Kinetics |
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290 | (1) |
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16.3.2 Hyperfine Couplings and Dynamic Reorientation |
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291 | (1) |
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291 | (1) |
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16.3.4 Vibrational Modes and Infrared Absorption |
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291 | (1) |
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16.3.5 Piezospectroscopic and Uniaxial Stress Experiments |
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291 | (1) |
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16.3.6 Electron Energy Loss Spectroscopy (EELS) |
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292 | (1) |
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16.4 Filter Diagonalisarion with Localisation Constraints |
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292 | (6) |
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294 | (2) |
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296 | (2) |
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16.5 Future Research Directions and Perspectives |
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298 | (4) |
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16.5.1 Types of Calculations |
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299 | (1) |
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16.5.1.1 Thousands of Atoms on a Desktop PC |
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299 | (1) |
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16.5.1.2 One Atom Per Processor |
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299 | (1) |
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16.5.2 Prevailing Application Trends |
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299 | (1) |
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16.5.3 Methodological Developments |
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300 | (2) |
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302 | (3) |
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302 | (3) |
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17 Ab Initio Green's Function Calculation of Hyperfine Interactions for Shallow Defects in Semiconductors |
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305 | (36) |
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305 | (1) |
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17.2 From DFT to Hyperfine Interactions |
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306 | (5) |
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17.2.1 DFT and Local Spin Density Approximation |
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306 | (2) |
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17.2.2 Scalar Relativistic Hyperfine Interactions |
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308 | (3) |
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17.3 Modeling Defect Structures |
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311 | (8) |
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17.3.1 The Green's Function Method and Dyson's Equation |
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311 | (2) |
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17.3.2 The Linear Muffin-Tin Orbital (LMTO) Method |
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313 | (2) |
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17.3.3 The Size of The Perturbed Region |
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315 | (2) |
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17.3.4 Lattice Relaxation: The AsGa-Family |
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317 | (2) |
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17.4 Shallow Defects: Effective Mass Approximation (EMA) and Beyond |
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319 | (9) |
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320 | (2) |
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17.4.2 Conduction Bands with Several Equivalent Minima |
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322 | (1) |
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17.4.3 Empirical Pseudopotential Extensions to the EMA |
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322 | (2) |
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17.4.4 Ab Initio Green's Function Approach to Shallow Donors |
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324 | (4) |
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17.5 Phosphorus Donors in Highly Strained Silicon |
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328 | (4) |
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17.5.1 Predictions of EMA |
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329 | (1) |
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17.5.2 Ab Initio Treatment via Green's Functions |
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330 | (2) |
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17.6 N-Type Doping of SiC with Phosphorus |
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332 | (2) |
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334 | (7) |
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336 | (5) |
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18 Time-Dependent Density Functional Study on the Excitation Spectrum of Point Defects in Semiconductors |
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341 | (18) |
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341 | (4) |
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18.1.1 Nitrogen-Vacancy Center in Diamond |
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342 | (2) |
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18.1.2 Divacancy in Silicon Carbide |
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344 | (1) |
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345 | (6) |
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18.2.1 Model, Geometry, and Electronic Structure |
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345 | (1) |
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18.2.2 Time-Dependent Density Functional Theory with Practical Approximations |
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346 | (5) |
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18.3 Results and Discussion |
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351 | (5) |
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18.3.1 Nitrogen-Vacancy Center in Diamond |
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351 | (2) |
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18.3.2 Divacancy in Silicon Carbide |
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353 | (3) |
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356 | (3) |
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356 | (3) |
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19 Which Electronic Structure Method for The Study of Defects: A Commentary |
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359 | (22) |
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19.1 Introduction: A Historic Perspective |
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359 | (3) |
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19.2 Themes of the Workshop |
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362 | (11) |
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19.2.1 Periodic Boundary Artifacts |
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362 | (5) |
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19.2.2 Band Gap Corrections |
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367 | (3) |
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19.2.3 Self-Interaction Errors |
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370 | (2) |
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372 | (1) |
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373 | (8) |
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375 | (6) |
| Index |
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381 | |