List of Examples and Exercises Example 8.1:Electron Densities of Substituted Benzenes....165 Example 8.2:Hydration Reactions166 Example 8.3:CH2OH2+CO IRC... …176 Example 8.4:CHOHCOH IRC.......... …179 Example 8.5:AH for an Isodesmic Reaction.............. …182 Example 8.6:Predicting the Heat of Formation of CO via an Isodesmic Reaction.................182 Example 8.7:Limitations of Isodesmic Reactions............. .183 Exercise 8.1:Hydration Reactions..... .185 Exercise 8.2:Bond Dissociation... 186 Exercise 8.3:HCO Potential Energy Surface.191 Exercise 8.4:Atomic Charge Analysis.. 4…194 Exercise 8.5:Group Charges....... …197 Advanced Exercise 8.6:Atoms in Molecules Charges and Bond Orders.... …198 Advanced Exercise 8.7:Si+Silane Potential Energy Surface......... 199 Advanced Exercise 8.8:Isodesmic Reactions....................... …204 Advanced Exercise 8.9:Heats of Formation via Isodesmic Reactions....... …206 Advanced Exercise 8.10:An SN2 Reaction.... .208 Example 9.1:Ethylene Excited States................. .214 Example 9.2:Formaldehyde Excited State Optimization.... .216 Exercise 9.1:Methylenecyclopropene Excited States............... .218 Exercise 9.2:Formaldehyde Excited State Optimization.220 Exercise 9.3:Acrolein Excited State Optimization.223 Advanced Exercise 9.4:Benzene Excitation Energies........................ 224 Advanced Exercise 9.5:Using the CASSCF Method to Study Excited State Systems.................. …228 Advanced Exercise 9.6:Using CASSCF to Study Butadiene Photochemistry............2.32 Example 10.1:Dichloroethane Conformer Energy Difference by Solvent...... …239 Example 10.2:Formaldehyde Frequencies in Acetonitrile................. .241 Exercise 10.1:Dichloroethane Conformer Energy Differences ........ .242 Exercise 10.2:Formaldehyde Frequencies..244 Exercise 10.3:Carbonyl Stretch in Solution............... 244 Advanced Exercise 10.4:Rotational Barrier in Solution for N-Methyl-2-Nitrovinylamine...........................246 Advanced Exercise 10.5:Comparing SCRF Methods on Furfuraldehyde.................. 247 Example A.1:Comparing Integration Grids..276 Exercise B.1:Z-Matrices for 1,2-Dichloro-1,2-Difluoroethane Isomers.................291 Exercise B.2:Mixed Cartesian and Internal Coordinates.........293 Exploring Chemistry with Electronic Structure Methods 湖List ofExamples and EuTci5es Example 8.1: Electron Densities of Substituted Benzenes 165 Example 8.2: Hydration Reactions 166 Example 8.3: CH20 -t H2+CO IRC 176 Example 8.4: CH20 -t HCOH IRC 179 Example 8.5: dH for an Isodesmic Reaction 182 Example 8.6: Predicting the Heat of Formation ofC02 via an Isodesmic Reaction 182 Example 8.7: Limitations ofIsodesmic Reactions 183 Exercise 8.1: Hydration Reactions 185 Exercise 8.2: Bond Dissociation 186 Exercise 8.3: H2CO Potential Energy Surface 191 Exercise 8.4: Atomic Charge Analysis 194 Exercise 8.5: Group Charges 197 Advanced Exercise 8.6: Atoms in Molecules Charges and Bond Orders 198 Advanced Exercise 8.7: Si+ +Silane Potential Energy Surface 199 Advanced Exercise 8.8: Isodesmic Reactions 204 Advanced Exercise 8.9: Heats ofFormation via Isodesmic Reactions 206 Advanced Exercise 8.10: An SN2 Reaction 208 Example 9.1: Ethylene Excited States 214 Example 9.2: Formaldehyde Excited State Optimization 216 Exercise 9.1: Methylenecyclopropene Excited States 218 Exercise 9.2: Formaldehyde Excited State Optimization 220 Exercise 9.3: Acrolein Excited State Optimization 223 Advanced Exercise 9.4: Benzene Excitation Energies 224 Advanced Exercise 9.5: Using the CASSCF Method to Study Excited State Systems 228 Advanced Exercise 9.6: Using CASSCF to Study Butadiene Photochemistry 232 Example 10.1: Dichloroethane Conformer Energy Difference by Solvent 239 Example 10.2: Formaldehyde Frequencies in AcetonitriIe 241 Exercise 10.1: Dichloroethane Conformer Energy Differences 242 Exercise 10.2: Formaldehyde Frequencies 244 Exercise 10.3: Carbonyl Stretch in Solution 244 Advanced Exercise 10.4: Rotational Barrier in Solution for N-Methyl-2-Nitrovinylamine 246 Advanced Exercise 10.5: Comparing SCRF Methods on Furfuraldehyde 247 Example A.I: Comparing Integration Grids 276 Exercise B.1: Z-Matrices for 1,2-Dichloro-l,2-Difluoroethane Isomers 291 Exercise B.2: Mixed Cartesian and Internal Coordinates 293 Exploring Chemistry with Electronic Structure Methods