The aim of the present work is to benchmark Slatertype approaches for core-level XPS. With the introduction of one element-specific parameter, we find that an empirically-shifted STM provides accuracy that is competitive with the contemporary many-body methods. Because this method connects CEBEs directly to oneparticle energy levels, it may provide direct chemical insight into the nature of chemical shifts, e.g., in timeresolved x-ray photoelectron spectroscopy experiments. As an example of a more complicated spectroscopy, we apply this method to compute valence-to-core (VtC) emission for a benchmark set of small molecules.