[Pw_forum] a questoin about pressure and bulk modulus of system

[meysam pazoki]

Dear  Stefano

Thanks for your good answer.I am an experimentalist and I learn good new
things from your answer.
My mistake was that I didnt know in calculation of pressure,we neglect
electronic degrres of freedom(I will be thankfull to you,if you introduce a
reference about this subject).
I have another question :Is these terms are right?
E=-PV+uN+TS => dE=-PdV-VdP+udN+Ndu+Tds+SdT
and we know from first law of thermodynamics that dE=-PdV+udN+Tds
and we conclude that -VdP+Ndu+SdT=0 and in zero temrature and fixed number
of atoms
we have dE=-PdV and P=-dE/dV

Thanks
Meysam pazoki
SUT
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