  Two new high-resolution X-ray spectroscopy missions, XRISM and Athena, will
observe deeper and with higher X-ray resolution than ever before possible.
Interpreting these new X-ray spectra will require understanding the impact that
uncertainties on fundamental atomic quantities such as collisional cross
sections, transition rates, and wavelengths have on spectral models. As
millions of values are required to generate even a simple model of an
optically-thin hot plasma, most such rates exist only as theoretical
calculations. We have developed methods to estimate the uncertainty in the
final spectral calculations based on published experimental data and plausible
approximations to the uncertainties in the underlying atomic data. We present
an extension to the pyatomdb code that implements these methods and investigate
the sensitivity of selected strong diagnostic lines in the X-ray bandpass
(0.3-12 keV).
