New developments in state-specific multireference coupled-cluster theory [Elektronische Ressource] / von Eric Prochnow

New Developments in State-Speci cMultireference Coupled-Cluster TheoryDissertation zur Erlangung des Grades,,Doktor der Naturwissenschaften"im Promotionsfach Chemieam Fachbereich Chemie, Pharmazie und Geowissenschaftender Johannes Gutenberg-Universit at in MainzvonEric Prochnowgeboren in RadebeulMainz, 2010ContentsContents1 Introduction 52 Theoretical Background 112.1 The Electronic Schr odinger Equation . . . . . . . . . . . . . . . . . . . . 112.2 Hartree-Fock Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122.3 Two-Con gurational Self-Consistent Field Theory . . . . . . . . . . . . . 152.4 Coupled-Cluster Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . 172.5 State-Speci c Multireference Coupled-Cluster Theory . . . . . . . . . . . 212.6 Molecular Properties as Analytical Derivatives . . . . . . . . . . . . . . . 282.7 Analytic Gradients in Coupled-Cluster Theory . . . . . . . . . . . . . . . 293 Development of an E cient Multireference Algorithm in CFOUR 333.1 Implementation of Mk-MRCCSD . . . . . . . . . . . . . . . . . . . . . . 333.2tation ofCCSDT . . . . . . . . . . . . . . . . . . . . . 364 Analytic First Derivatives for the Mk-MRCC Ansatz 384.1 The Lagrangian of the Mk-MRCC Ansatz . . . . . . . . . . . . . . . . . 394.2 Mk-MRCC Energy Gradient Expression . . . . . . . . . . . . . . . . . . 404.3 Lambda Equations and Lagrange Multipliers c in the Mk-MRCC Approach 414.