  Accurate atomic data and plasma models are essential for interpreting the
upcoming high-quality spectra from missions like XRISM and Athena. Estimating
physical quantities, like temperature, abundance, turbulence, and resonance
scattering factor, is highly dependent on the underlying atomic data. We use
the AtomDB tool variableapec to estimate the impact of atomic data
uncertainties in Einstein A coefficients, collisional rate coefficient,
ionization and recombination rates in H-, He- and Li-like iron in modeling the
spectrum of Perseus observed by Hitomi. The best-fit temperature, abundance,
resonance scattering factor, and turbulence including atomic data
uncertainties, varied approximately 17%, 35%, 30%, and 3%, respectively, from
the best-fit temperature, abundance, resonance scattering factor, and
turbulence estimated without atomic data uncertainties. This indicates that,
approximately 32%, 35%, and 25% of the best-fit temperatures, abundances, and
resonance scattering factors, including uncertainties lie outside the 3$\sigma$
error regions of their corresponding best-fit values computed with zero atomic
data error. Expanding the energy range to 1.8-20.0 keV shows less variability,
with 26% of the abundances and 22% of the resonance scattering factors lying
outside the 3$\sigma$ error of the best-fit values.
  We also studied correlations between physical parameters and atomic rate
uncertainties to identify key atomic quantities requiring precise lab
measurements. We report negative correlations between best-fit temperature and
z (1s.2s $^{3}\rm S_{1}\rightarrow 1s^{2}$) collisional rate coefficient,
abundance and y (1s.2p $^{3}\rm P_{1}\rightarrow 1s^{2}$) collisional rate
coefficient, abundance and z collisional rate coefficient, and positive
correlation between resonance scattering factor and w (1s.2p $^{1}\rm
P_{1}\rightarrow 1s^{2}$) collisional rate coefficient.
