This note presents revised detector parameters applicable to data from the
First Science Run of the ZEPLIN-III dark matter experiment; these datasets were
acquired in 2008 and reanalised in 2011. This run demonstrated electron recoil
discrimination in liquid xenon at the level of 1 part in 10,000 below 40 keV
nuclear recoil energy, at an electric field of 3.8 kV/cm; this remains the best
discrimination reported for this medium to date. Building on relevant
measurements published in recent years, the calibration of the scintillation
and ionisation responses for both electron and nuclear recoils, which had been
mapped linearly to Co-57 gamma-ray interactions, is converted here into optical
parameters which are better suited to relate the data to the emerging liquid
xenon response models. Additional information is given on the fitting of the
electron and nuclear recoil populations at low energy. The aim of this note is
to support the further development of these models with valuable data acquired
at high field.