A QM/QM hybrid method for MP2/plane-wave-DFT studies of extended systems [Elektronische Ressource] / von Christian Tuma

A QM/QM HYBRID METHOD FORMP2/PLANE-WAVE-DFT STUDIES OFEXTENDED SYSTEMSDissertationzurErlangungdesakademischenGradesdoctor rerum naturalium(Dr.rer.nat.)imFachChemieeingereichtanderMathematisch NaturwissenschaftlichenFakultätIderHumboldt UniversitätzuBerlinvonHerrnDipl. Chem.ChristianTumageborenam04.11.1974inBerlinPräsidentderHumboldt UniversitätzuBerlinProf.Dr.ChristophMarkschiesDekanderMathematisch NaturwissenschaftlichenFakultätIProf.Dr.ChristianLimbergGutachter: 1. Prof.Dr.JoachimSauer2. Prof.Dr.MatthiasScheffler3. Prof.PieroUgliengoTagdermündlichenPrüfung: 14.Dezember2006iiiiiAbstractDuetotheircomparativelyhighefficiencystandardmethodsindensityfunctional theory (DFT) belong to the most popular computational ap proachesinquantummechanics(QM).Incertainapplications,however,widely used density functionals do not yield reliable results. This ap plies,forexample,tothecalculationofactivationbarriersordispersiveinteractions. Problemsofthistypecanbeovercomeinprinciplebyusingelectroncorrelationmethods,butinmanycasestoohighcomputationalcosts rule out their application. The simplest QM method for electroncorrelation,second orderMøller–Plessetperturbationtheory(MP2),de scribesdispersionwell.Inthisworkahybridmethod solelybaseduponQMapproaches ispresented,combiningadvantagesofbothDFTandelectroncorrelationmethods. DFT calculations are performed for the full system and anembeddedclustermodelrepresentingtheactivesite.