Скачать или смотреть Rotational Partition Function and Entropy of Symmetric Tops

You may run the python code here:
https://www.w3schools.com/python/tryp...
(Replace "IS LESS THAN" in the following code with the angled bracket.)

import math

def Qrot(T):
Qrot=0.0
for J in range (0, Jmax+1):
for K in range(-J, J+1): # K can be -J, -J+1, ..., 0, ..., J
Erot=B*J*(J+1)+(A-B)*K*K # Rotational energy of a symmetric top
if (Erot IS LESS THAN Emax):
Qrot=Qrot+(2*J+1)*math.exp(-Erot/T)
print("Emax= %.2f T= %.2f Qrot= %.5f" % (Emax, T, Qrot))
return(Qrot)

def Srot(T):
dT=0.01 # Finite difference method
x=Qrot(T)
y=Qrot(T+dT)
S = R(lnq + d(lnq)/d(lnT))
Srot=8.31446*(math.log(x)+math.log(y/x)/math.log((1+dT/T)))
return(Srot)

Emax=200.0 # Maximum rotational temperature in K
T=180.0 # in K
A=5.0 # in K calculated with a computational chemistry program
B=0.5 # in K calculated with a computational chemistry program
Jmax=int(math.sqrt(Emax/B)+1) # the maximum value of J
print("Emax= %.2f T= %.2f Qrot= %.3f Srot= %.3f J/(mol K)" % (Emax, T, Qrot(T), Srot(T)))