Focusing on spectroscopic properties of molecular systems, Quantum Modeling of Molecular Materials presents the state-of-the-art methods in theoretical chemistry that are used to determine molecular properties relevant to different spectroscopies. This timely reference gives a basic presentation of response theory and its application to the simulation of spectroscopic properties of molecular materials. This in-depth presentation of time-dependent response theory and its applications in spectroscopy provides an important advance towards a modern vision of theoretical tools for researchers in academia and industry and postgraduate students.