The original NASA thermo data file format was documented in:
S. Gordon and B.J. McBride, "Computer Program for Calculation of Complex
Chemical Equilibrium Composition, Rocket Performance, Incident and Reflected
Shocks and Chapman-Jouguet Detonations", NASA SP-273 (1971).
The following information is quoted directly from that document.
Eqs. 90, 91, and 92 give polynomial functions for the specific heat,
enthalpy, and entropy. The coefficients are given as data.
Eq. 90: cp0/R=a1+a2T+a3*T^2+a4*T^3+a5*T^4
Eq. 91: H0_T/(RT)=a1+a2/2*T+a3/3*T^2+a4/4*T^3+a5/5*T^4+a6/T
Eq. 92: S0_T/R=a1*ln(T)+a2*T+a3/2*T^2+a4/3*T^3+a5/4*T^4+a7
Appendix D: Thermo Data (Format and Listing)
Card Contents Format Card
Order Column
1 THERMO 3A4 1 to 6
2 Temperature ranges for 2 sets of coefficients: 3F10.3 1 to 30
lowest T, common T, and highest T
3 Species name 3A4 1 to 12
Date 2A3 19 to 24
Atomic symbols and formula 4(A2,F3.0) 25 to 44
Phase of species (S, L, or G for solid, liquid, A1 45
or gas, respectively)
Temperature range 2F10.3 46 to 65
Integer 1 I5 80
4 Coefficients ai (i=1 to 5) in equations (90) 5(E15.8) 1 to 75
to (92) (for upper temperature interval)
Integer 2 I5 80
5 Coefficients in equations (90) to (92) (a6, a7, 5(E15.8) 1 to 75
for upper temperature interval, and a1, a2, and
a3 for lower)
Integer 3 I5 80
6 Coefficients in equations (90) to (92) (a4, a5, 4(E15.8) 1 to 60
a6, a7 for lower temperature interval)
Integer 4 I20 80
(a) Repeat cards numbered 1 to 4 in cc 80 for each
species
(Final END (Indicates end of thermodynamic data) 3A4 1 to 3
card)
Gaseous species and condensed species with only one condensed phase can be in
any order. However, the sets for two or more condensed phases of the same
species must be adjacent. If there are more than two condensed phases of
a species, their sets must be either in increasing or decreasing order
according to their temperature intervals.
The following example illustrates a thermo data file with a single species.
Additional species would be added by duplicating lines 3 through 6:
THERMO
200.0 1000.0 6000.0
Br J6/82BR 1 0 0 0G 200.000 6000.000 1
2.08851053E+00 7.12118611E-04-2.70003073E-07 4.14986299E-11-2.31188294E-15 2
1.28568767E+04 9.07351144E+00 2.48571711E+00 1.50647525E-04-5.37267333E-07 3
7.20921065E-10-2.50205558E-13 1.27092168E+04 6.86030804E+00 1.34535890E+04 4
END
Notes:
1. The minimum and maximum temperatures given on the second line of the
file are meant to be global min and max values, where each species
provides a specific, presumably more restrictive, range. The middle
temperature on the second line is the common temperature for the high
and low temperature ranges for all species in the file.
2. Some files (such as the example, above) provide an additional value
in the normally unused last field. This is the enthalpy of formation,
divided by the gas constant, and is redundant with Eq. 91.
3. Although the use of columns 66 to 79 of the first line of species data
is not specified, it is often used for the molecular weight.