We have discovered, thanks to Michael Loewenstein, a mistake in the AtomDB v2.0.0 release which has necessitated the release of v2.0.1. The error was in the iron radiative recombination continuum, which was overestimated for certain iron ions (specifically Fe XVIII and Fe XXI) by up to a factor of ~8 due to incorrect data in the database for the recombination to the ground state. In addition, we have identified other ions where the ground state recombination was mistakenly omitted. In both equilibrium and ionizing plasmas, the recombination continua from iron ions is a minor term relative to the bremsstrahluing continuum, so this omission did not create any noticeable impact. Nonetheless, it has been fixed in the new release.
Since the error was limited to recombination to the ground state, there is no impact to any line emission.
We recommend all users of AtomDB update to the new version immediately, and not use the Version 2.0.0 data. We apologize for any confusion or mistakes caused by the error.