  This work presents the catalogue of optical spectral properties for all X-ray
selected SPIDERS active galactic nuclei (AGN) up to SDSS DR14. SPIDERS
(SPectroscopic IDentification of eROSITA Sources) is an SDSS-IV programme that
is currently conducting optical spectroscopy of the counterparts to the X-ray
selected sources detected in the ROSAT all-sky survey and the XMM-Newton slew
survey in the footprint of the Extended Baryon Oscillation Spectroscopic Survey
(eBOSS). The SPIDERS DR14 sample is the largest sample of X-ray selected AGN
with optical spectroscopic follow-up to date. The catalogue presented here is
based on a clean sample of 7344 2RXS ($\rm \bar{z}$ = 0.5) and 1157 XMM-Newton
slew survey ($\rm \bar{z}$ = 0.4) type 1 AGN with spectroscopic coverage of the
H$\rm \beta$ and/or MgII emission lines. Visual inspection results for each
object in this sample are available from a combination of literature sources
and the SPIDERS group, which provide both reliable redshifts and source
classifications. The spectral regions around the H$\rm \beta$ and MgII emission
lines have been fit in order to measure both line and continuum properties,
estimate bolometric luminosities, and provide black hole mass estimates using
the single-epoch (or photoionisation) method. The use of both H$\rm \beta$ and
MgII allows black hole masses to be estimated up to z $\rm \simeq$ 2.5. A
comparison is made between the spectral properties and black hole mass
estimates derived from H$\rm \beta$ and MgII using the subsample of objects
which have coverage of both lines in their spectrum. These results have been
made publicly available as an SDSS-IV DR14 value added catalogue.
