Species input parameters (parameter -- description -- options, with default given first):

species_option -- determines how species parameters are specified -- 'analytic' or 'iterdb'
species_file -- file with species input data (if using 'iterdb' option) -- path of geo input file
species_time -- time during discharge to sample experimental data in seconds (if using 'iterdb option)
ntspec -- number of species to evolve -- default 2
qi -- reference ion species charge (in units of proton charge) -- default 1
mi -- reference ion species mass (in units of proton mass) -- default 2.0
zeff -- average effective charge (only needed if profile of zeff not given by ITER db file -- default 1.0
deuterium -- x-label in ITER db to look for deuterium density ("NMx") -- default 1
tritium -- x-label in ITER db to look for tritium density ("NMx") -- default 2
impurity -- x-label in ITER db to look for impurity density ("NMx") -- default 3