3.2. Species Data

Each chemical species in a problem must be identified on one or more species line(s). Any set of up to 16 upper or lower case characters can be used as a species name. In addition each species must be composed of elements that have been identified in the element data. As for the element data, one of the primary purposes of the species data is to identify the order in which arrays of species information are referenced in the Gas-phase Kinetics Subroutine Library.

Species data must start with the word SPECIES (or SPEC), followed by any number of species symbols on any number of lines. Species symbols may appear anywhere on a line, but those on the same line must be separated by blank spaces. Any line or portion of a line starting with an exclamation mark (!) is considered to be a comment and will be ignored. Blank lines are ignored. Figure 3.2: Examples of Species Data shows several equivalent ways to describe species information.

Figure 3.2: Examples of Species Data

SPECIES    H2  O2  H  O  OH  HO2  N2  N  NO  END

SPEC                                      ! SPEC is equivalent to SPECIES
  H2  O2
  H  O  OH  HO2  N2  N  NO
END

SPEC H2
spec O2

The rules for species data are summarized in Table 3.2: Summary of the Rules for Species Data .

Table 3.2: Summary of the Rules for Species Data

Rule	Description
1	Species data must start with the word `SPECIES` (or `SPEC`).
2	Species names are composed of up to 16-character upper- or lower- case symbols. The names cannot begin with the characters `+`, `=`, or a number; an ionic species name may end with one or more `+` 's or `-` 's.
3	Each species should be declared only once; however, duplicated species symbols will be ignored.
4	Each species that subsequently appears in a reaction must be declared.
5	A species name may appear anywhere on the line.
6	Any number of species names may appear on a line, and more than one line may be used.
7	Species named on the same line must be separated by at least one blank space.
8	A species name that begins on one line may not continue to the next line.
9	There may be more than one `SPECIES` statement.
10	All characters following an exclamation mark are comments.
11	For best results, an `END` statement should follow a species group.