The calculation of NSCD spectra has so far only been implemented within the framework of time-dependent (TD-) density functional theory (DFT). One TD-DFT protocol for NSCD is based on the complex polarization propagator (CPP) method. This approach allows to simulate directly the absorption spectra with broadened bands and to investigate regions of arbitrary energy without the explicit need to calculate all excited states of lower energy. However, it partly obscures the contributions of individual excited states as the resulting spectrum is a sum of all contributions that are implicitly convoluted with Lorentzian broadening bands. More recently, a TD-DFT quadratic-response-based approach has been developed for calculating the NSCD strengths of individual transitions. This approach produces NSCD data in the form of "stick spectra", i.e., NSCD strengths of a particular nucleus K over a given set of excited states, known as NSCD B K terms.