The tardy dance of molecular orbitals. Issue 20 (4th September 2018)

• Record Type: Journal Article
• Authors: Frank, Irmgard; Kraus, Peter
• Is Part Of: International journal of quantum chemistry. Volume 118:Issue 20(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-09-04
• Subjects: density functional theory -- molecular dynamics -- orbitals; Quantum chemistry -- Periodicals; 541.28
• DOI: 10.1002/qua.25718
• Languages: English
• ISSNs: 0020-7608

Abstract

Abstract: Molecular orbitals are obtained readily from quantum chemical calculations. Their densities sum up to the total electronic cloud which determines structure and reactivity of every system consisting of atoms, that is, of any kind of matter. The present study shows the flexibility but also the tardiness of molecular orbitals in slow motion movies. With such movies it is easy to get familiar with orbitals and with their motion on the picometer and femtosecond scales, but there are phenomena which also surprise the expert. As an example, the photochemistry and photophysics of butadiene is investigated. Abstract : The spontaneous, ultra‐fast ground state dimerization of cyclobutadiene is taken as an example for a chemical reaction that can be modeled by first‐principles molecular dynamics. Movies of the simulations show either the role of single orbitals or that of the total energy. Such 3D movies are easy to understand and, at the same time, transport a lot of information about chemical reactions. Nevertheless, some features are not to be over‐interpreted as the comparison between different program packages shows.