pkReadSpecies reads in the input file the
NAMELIST instructions characterizing the chemical species and processes
this information. If the species is an excited species or an ion, the value of
some properties are inherited from the parent species; vibrational series
are split into individual species and species concentration and energy are
calculated; and finally the species are classified and sorted according to the
classification of Figure F-2.
pkReadSpecies( UNIT[, IOSTAT] )