Another question from Ashcroft and Mermin: Fermi-Dirac Distribution

[hagopbul]

TL;DR

this time about fermi -dirac distribution

Good Day :

i reached the page 40 of Ashcroft Mermin book and after the equation 2.38 there is this expression of E(a,N) which is equal to Helmoltez Free energy F = U - TS , how this two terms F , E are related ? anyone can provide adequate explanation , and few useful references

Best Regards
HB

 

[anuttarasammyak]

I do not have the book. What is a ?

 

[hagopbul]

ath stationary state of N-electron system

 

[Lord Jestocost]

Summary:: this time about fermi -dirac distribution

i reached the page 40 of Ashcroft Mermin book and after the equation 2.38 there is this expression of E(a,N) which is equal to Helmoltez Free energy F = U - TS , how this two terms F , E are related ? anyone can provide adequate explanation , and few useful references

The sum in the denominator of eq. 2.38 is the “canonical ensemble partition function” Q(N, V, T) of the considered N-electron system at volume V and temperature T. From statistical thermodynamics one has for the Helmholtz free energy F(N, V, T) of a closed system: F(N, V, T) = -kT lnQ(N, V, T)

https://en.wikipedia.org/wiki/Helmholtz_free_energy