Partition functionsΒΆ
Please provide the line lists, temperature step Ntemp and the
maximum of the temperature Tmax.
Ntemp is always set as 1 K.
Tmax can be set by yourself and the definition file .def from
the ExoMol database provides the maximum temperature of each molecule
for reference.
The temperatures are start from 1 K to Tmax K in the output file.
The partition functions equation is:
\[
Q(T)=\sum_n g_n^{\textrm{tot}} e^{-c_2\tilde{E}_n/T}.
\]
Example
# Data source #
Database ExoMol
Molecule CO2
Isotopologue 12C-16O2
Dataset UCL-4000
SpeciesID 21
# File path #
ReadPath /mnt/data/exomol/exomol3_data/
SavePath /home/jingxin/data/pyexocross/
LogFilePath /home/jingxin/data/pyexocross/log/CO2_ExoMol_pf.log
# Functions #
Conversion 0
PartitionFunctions 1
SpecificHeats 0
CoolingFunctions 0
Lifetimes 0
OscillatorStrengths 0
StickSpectra 0
CrossSections 0
# Cores and chunks #
NCPUtrans 1
NCPUfiles 1
ChunkSize 1000000
# Calculate partition, specific heats or cooling functions #
Ntemp 1 # The number of temperature steps
Tmax 5000 # Maximal temperature in K
Note
For HITRAN/HITEMP input, partition functions are calculated directly from the
line list records; format conversion and quantum number settings are not
required.
At high temperature, the result may differ from HITRAN/TIPS values because a .par file is a transition list and may not contain a complete set
of high energy states.