There are some cases where you may want to define very large molecules that contain many
elements or that may be composed of a very large number of atoms for a particular element.
For this purpose, Chemkin extends the thermodynamic data format to allow you to provide an
unlimited number of elements and unconstrained composition. Figure 2.3: Examples of Very Large Molecules shows an example (for
illustration purposes only) of using this extended format to describe a molecule called
CLUSTER1 that consists of 2326 carbon atoms, 895 hydrogen atoms, 18
nitrogen atoms, 53 oxygen atoms, and 32 sulfur atoms. The extended format is enabled by
putting a & character at the end of Line 3 (Table 2.1: Summary of the Rules for Thermodynamic Data), in column 81. Any number of
continuation lines may subsequently be included by adding an ampersand
(&) at the end of a preceding line. The composition information
used on these continuation lines is in free format, which consists of an element symbol,
followed by the number of those atoms in the molecule, followed by another element symbol,
and so forth.
Figure 2.3: Examples of Very Large Molecules
CLUSTER1 121086 G 300.000 5000.000 1000.00 1& C 2326 H 895 N 18 O 53 S 32 2.60208700e+00-1.78708100e-04 9.08704100e-08-1.14993300e-11 3.31084400e-16 2 8.54215400e+04 4.19517700e+00 2.49858500e+00 8.08577700e-05-2.69769700e-07 3 3.04072900e-10-1.10665200e-13 8.54587800e+04 4.75345900e+00 4