This chapter presents the methodology for the quantum five-dimensional (5D) calculations of the translation-rotation (TR) eigenstates of H2@C60, and the TR energy level structure that emerged from these calculations and a perturbation-theory (PT) treatment. It also presents the methodology for the quantum six-dimensional (6D) calculations of the TR eigenstates of H2O@C60 and the resulting TR energy level structure. A comprehensive description of the dynamical behavior of H2O in C60, especially the characterization of its translational excitations and their coupling to the quantized H2O rotations, which eluded experiments, had to await the rigorous quantum 6D calculations of the TR eigenstates of H2O@C60. Combined high-level theoretical and spectroscopic investigations of H2@C60 and H2O@C60 have resulted in deep understanding and quantitative description of the intricate quantum TR dynamics of the guest molecules arising from their confinement inside a nanocavity of high symmetry.
This chapter reviews the use of phase-space-lattice (PSL) basis sets in computational quantum dynamics (QD), as well as other basis sets that are truncated using PS means. It compares and contrasts these methods with respect to scaling, accuracy, and implementation, in order to establish a set of practical guidelines as to which should be used when. Throughout the discussion, the chapter attempts to make a distinction between what is known mathematically versus what appears to be suggested from the numerical evidence currently available. Very recently, other researchers have become interested in applying two specific PSL methods in the context of extremely highly accurate calculations. The chapter repeats the calculation of the coefficients to much higher precision - and provides a correspondingly more complete set of tables. It also presents some preliminary results pertaining to the application of PSL ideas to the realm of electron QD.
Photodetachment is a photoinduced process, in which an electron in a stable anionic atom or molecule is ejected. The kinetic energy of the ejected electron can be readily measured, which gives rise to the so-called photoelectron spectroscopy. This chapter focuses on theoretical studies of photodetachment dynamics of anion molecules beyond triatomics. It describes some of the latest advances in this area, driven by progress in constructing high-dimensional ab initio-based potential energy surfaces (PESs) and in quantum dynamical algorithms. The chapter discusses quantum mechanical studies as many quantum effects, such as tunneling and resonances, are important in photodetachment processes. It highlights that these theoretical studies help to better understand the experimental measurements, which in turn challenge theory. These new insights are highly relevant to reaction dynamics in polyatomic systems. The chapter reviews several examples of such systems, namely FCH4 −, HCO2 −, H2CC−, H3O−, FH2O−, HOCO−, and NH4 −.
This chapter provides a simple pedagogical presentation of the discrete variable representation (DVR). It reviews the von Neumann (vN) basis of phase-space Gaussians which include the Projected von Neumann Basis (PvN) and the Biorthogonal von Neumann Basis (PvB). The chapter includes a variety of interesting formal properties of nonorthogonal bases that are an extension of the DVR presentation and provides insight into the method. It presents an analysis of multidimensional considerations, including details of a highly efficient tensor formulation for performing pruned multidimensional DVR calculations for sparse but unstructured grids. The chapter contains illustrative applications. Pruned phase-space methods have been successfully used for computing eigenenergies of (ro-) vibrational systems. The chapter focuses on the applications in the context of solving the time-dependent Schrodinger equation (TDSE). The efficiency of phase-space versus coordinate-space methods will certainly depend on the particular system studied and the strength of coupling between degrees of freedom.
Developments in the foundations of quantum mechanics have identified several attributes and tests associated with the "quantumness" of systems, including entanglement, nonlocality, quantum erasure, Bell test, etc. Here we introduce and utilize these tools to examine the role of quantum coherence and nonclassical effects in 1 vs. N photon coherent phase control, a paradigm for an all-optical method for manipulating molecular dynamics. In addition, truly quantum control scenarios are introduced and examined. The approach adopted here serves as a template for studies of the role of quantum mechanics in other coherent control and optimal control scenarios.
This chapter summarizes the history, principles, and energetic and nanostructural designs for small-molecular-type organic solar cells. It discusses estimation of the exciton diffusion length. The chapter describes a fabrication method for pseudo-vertical superlattices. This method is generally applicable for growing high-quality phase-separated/crystalline co-deposited films for vacuum-deposited small-molecular-type organic solar cells. The chapter also summarizes "seven-nines" (7N) purification, pn-control of single and co-deposited organic semiconductors by doping, doping sensitization, and ppm-doping effects. It focuses on the high purification of organic semiconductors. The chapter shows that the science of doping in organic semiconductors is indispensable to the development of organic solar cells, which have the potential to provide the next generation of low-cost solar cells. The field of organic solar cells is closely related to many other research fields such as device physics, electronics, and synthetic chemistry, in which there are a vast number of researchers.
Chapter 5 Chemistry With Controlled Ions Stefan Willitsch, Stefan Willitsch Department of Chemistry, University of Basel, Klingelbergstrasse 80, 4056 Basel, SwitzerlandSearch for more papers by this author Stefan Willitsch, Stefan Willitsch Department of Chemistry, University of Basel, Klingelbergstrasse 80, 4056 Basel, SwitzerlandSearch for more papers by this author Book Editor(s):Stuart A. Rice, Stuart A. Rice The University of Chicago, Illinois, USSearch for more papers by this authorAaron R. Dinner, Aaron R. Dinner The University of Chicago, Illinois, USSearch for more papers by this author First published: 28 August 2017 https://doi.org/10.1002/9781119324560.ch5Citations: 16Book Series:Advances in Chemical Physics AboutPDFPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShareShare a linkShare onFacebookTwitterLinked InRedditWechat Summary This chapter focuses on the application of controlled-molecule techniques for precise studies of ion-molecule reactions in the gas phase. It gives an overview of the most important techniques presently used for the control of the translational motion, internal quantum states, and structural properties of molecular ions and neutral molecules in the gas phase. Besides the control of the translational motion, preparation of the internal quantum state of molecular ions is a main prerequisite on the way to controlling chemical reactions. Since the 1980s, (multiphoton) photoionization has been a key method for preparing molecular ions in selected internal states. Various variants of this approach have been implemented. The chapter further gives a brief outline of salient concepts of ion-molecule reaction dynamics which are relevant for the present discussion. Finally, the chapter presents some illustrative examples in which cold- and controlled-molecule techniques have been used to study the mechanisms and dynamics of ionic reactions. Citing Literature Advances in Chemical Physics, Volume 162 RelatedInformation
This chapter introduces the weak-coupling configuration interaction (CI) theory of low-lying states in organic molecules such as the oligoacenes and makes connections to more accurate computational techniques. This overview establishes the electronic structure language relevant for singlet fission and introduces the notion of charge-transfer (CT) configurations, whose importance was recognized very early on in the field of molecular excitons. The considered CT configurations are only for nearest-neighbor pairs; in principle, non-nearest-neighbor pairs could also be included, which would allow for larger exciton sizes and coupling into the manifold of dissociated exciton states (i.e., free electron-hole pairs). The chapter also discusses the difficulties and techniques associated with the quantification of CT character in low-lying excited states. The most straightforward measure of CT character is the dipole moment. Having established the generic presence of CT states, the chapter further discusses the implications for singlet fission.
We review methods of data analysis for biophysical data with a special emphasis on single molecule applications. Our review is intended for anyone, from student to established researcher. For someone just getting started, we focus on exposing the logic, strength and limitations of each method and cite, as appropriate, the relevant literature for implementation details. We review traditional frequentist and Bayesian parametric approaches to data analysis and subsequently extend our discussion to recent non-parametric and information theoretic methods.
