Time versus frequency space techniques

Abstract

Let us imagine a young student (or a not so young professor who still has time to do research by him- or herself) who wants to make an ab-initio study of the excitation properties of one of those fashionable nanostructures that fill high-impact journals nowadays. The student has heard of TDDFT, and believes that it’s just the right tool for the job. The first thing to do is to make sure that his fancy molecule is not part of the set of the difficult, “pathological” cases – not a bulk semiconductor, check!; the system does not involve charge-transfer excitations, check!; not a “strongly-correlated” system, check! As everything looks fine, the student starts the quest to find an adequate computer program to use in his or her research.