The Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey:
  BAO and RSD measurements from anisotropic clustering analysis of the Quasar
  Sample in configuration space between redshift 0.8 and 2.2
  We measure the anisotropic clustering of the quasar sample from Data Release
16 (DR16) of the Sloan Digital Sky Survey IV extended Baryon Oscillation
Spectroscopic Survey (eBOSS). A sample of $343,708$ spectroscopically confirmed
quasars between redshift $0.8<z<2.2$ are used as tracers of the underlying dark
matter field. In comparison with DR14 sample, the final sample doubles the
number of objects as well as the survey area. In this paper, we present the
analysis in configuration space by measuring the two-point correlation function
and decompose using the Legendre polynomials. For the full-shape analysis of
the Legendre multipole moments, we measure the BAO distance and the growth rate
of the cosmic structure. At an effective redshift of $z_{\rm eff}=1.48$, we
measure the comoving angular diameter distance $D_{\rm M}(z_{\rm eff})/r_{\rm
drag} = 30.66\pm0.88$, the Hubble distance $D_{\rm H}(z_{\rm eff})/r_{\rm drag}
= 13.11\pm0.52$, and the growth rate $f\sigma_8(z_{\rm eff}) = 0.439\pm0.048$.
The accuracy of these measurements is confirmed using an extensive set of mock
simulations developed for the quasar sample. The uncertainties on the distance
and growth rate measurements have been reduced substantially ($\sim 45\%$ and
$\sim30\%$) with respect to the DR14 results. We also perform a BAO-only
analysis to cross check the robustness of the methodology of the full-shape
analysis. Combining our analysis with the Fourier space analysis, we arrive at
$D^{\bf{c}}_{\rm M}(z_{\rm eff})/r_{\rm drag} = 30.22 \pm 0.79$,
$D^{\bf{c}}_{\rm H}(z_{\rm eff})/r_{\rm drag} = 13.26 \pm 0.47$, and
$f\sigma_8^{\bf{c}}(z_{\rm eff}) = 0.464 \pm 0.045$.
