No subject

Doing this, one gets (from calculated):

C_v(300K)=2.7491*8.314=22.856 J/mol/K, C_v(500K)=24.164 J/mol/K





By the way, you have mistaken. 3N in F_QHA.f90 refers to the total number of phonon modes and has no commons with "mol" unit. 



Bests,

Eyvaz.

P.S. In Kittel's textbook provided C_p is about 4.7 cal/mol/K (most likely per atom) Introduction to solid state physics (1996); Fig.5.8



-------------------------------------------------------------------

Prof. Eyvaz Isaev, 

Department of Physics, Chemistry, and Biology (IFM), Linkoping University, Sweden 

Theoretical Physics Department, Moscow State Institute of Steel & Alloys, Russia, 

isaev at ifm.liu.se, eyvaz_isaev at yahoo.com



--- On Mon, 5/24/10, Yamit  wrote:



From: Yamit 

Subject: Re: [Pw_forum] About F_QHA.x

To: pw_forum at pwscf.org

Date: Monday, May 24, 2010, 6:28 PM







Dear Prof Nicola Marzari







Thank you for your reply! The phonon values from this work are in good agreement (with error of ~1-2 %) with the values reported in Giannozzi, PRB 43-7231-1991.







=====================================================



Table :(Frequency in cm^{-1},)







- & Current work & PRB 43-7231-1991 







Gamma_{TO/LO} & 525.350461 & 517 







L_{TA} & 109 & 111 



L_{LA} & 379 & 378 



=========================================================











As the output of "F_QHA.x", I have obtained the following results, (in QHA.out file)







############################################################################################################







# T in K, F_vib in Ry/cell, C_v in R (the universal gas constant by 3N modes), S in k_B



############################################################################################################



# T E_internal F_vibration Specific heat (C_v) Entropy



############################################################################################################



:



:



295.00 0.0139740852 0.0055747646 4.6621714979 4.4956255367



300.00 0.0141222695 0.0054311560 4.6966380876 4.5742737931



305.00 0.0142715257 0.0052850687 4.7298757363 4.6521815403



310.00 0.0144218157 0.0051365259 4.7619351485 4.7293532915



:



:



:



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