Title: Semiclassical Molecular Dynamics for Spectroscopic Calculations
Abstract: We present some historical and recently developed techniques to perform semiclassical spectroscopy calculations with both ground and excited state dynamics. The illustrated topics begin with a derivation of the basic semiclassical van Vleck propagator starting from Feynman's path integral formulation, followed by the description of the initial value representation formalism and a derivation of the Heller–Herman–Kluk–Kay semiclassical propagator. The chapter continues by introducing the time averaging technique and its very recent developments consisting in the multiple coherent, divide-and-conquer, and mixed semiclassical approaches. The main features of each method are described through examples with the intent of helping readers have a gentle learning curve. The chapter ends with a workflow chart, a few representative applications, a summary, and some conclusions.