<br /> <br /> <br /> Doing this, one gets (from calculated):<br /> <br /> C_v(300K)=3D2.7491*8.314=3D22.856 J/mol/K, C_v(500K)=3D24.164 J/mol/K<br /> <br /> <br /> <br /> <br /> <br /> By the way, you have mistaken. 3N in F_QHA.f90 refers to the total number o= f phonon modes and has no commons with "mol" unit. <br /> <br /> <br /> <br /> Bests,<br /> <br /> Eyvaz.<br /> <br /> 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<br /> <br /> <br /> <br /> -------------------------------------------------------------------<br /> <br /> Prof. Eyvaz Isaev, <br /> <br /> Department of Physics, Chemistry, and Biology (IFM), Linkoping University, = Sweden <br /> <br /> Theoretical Physics Department, Moscow State Institute of Steel & Alloys, R= ussia, <br /> <br /> isaev at ifm.liu.se, eyvaz_isaev at yahoo.com<br /> <br /> <br /> <br /> --- On Mon, 5/24/10, Yamit <amit99266 at rediffmail.com> wrote:<br /> <br /> <br /> <br /> From: Yamit <[email protected]><br /> <br /> Subject: Re: [Pw_forum] About F_QHA.x<br /> <br /> To: pw_forum at pwscf.org<br /> <br /> Date: Monday, May 24, 2010, 6:28 PM<br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> Dear Prof Nicola Marzari<br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> Thank you for your reply! The phonon values from this work are in good agre= ement (with error of ~1-2 %) with the values reported in Giannozzi, PRB 43-= 7231-1991.<br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D<br /> <br /> <br /> <br /> Table :(Frequency in cm^{-1},)<br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> - & Current work & PRB 43-7231-1991 <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> Gamma_{TO/LO} & 525.350461 & 517 <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> L_{TA} & 109 & 111 <br /> <br /> <br /> <br /> L_{LA} & 379 & 378 <br /> <br /> <br /> <br /> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D<br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> As the output of "F_QHA.x", I have obtained the following results, (in QHA.= out file)<br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> ###########################################################################= #################################<br /> <br /> <br /> <br /> <br /> <br /> <br /> <br /> # T in K, F_vib in Ry/cell, C_v in R (the universal gas constant by 3N mode= s), S in k_B<br /> <br /> <br /> <br /> ###########################################################################= #################################<br /> <br /> <br /> <br /> # T E_internal F_vibration Specific heat (C_v) Entropy<br /> <br /> <br /> <br /> ###########################################################################= #################################<br /> <br /> <br /> <br /> :<br /> <br /> <br /> <br /> :<br /> <br /> <br /> <br /> 295.00 0.0139740852 0.0055747646 4.6621714979 4.4956255367<br /> <br /> <br /> <br /> 300.00 0.0141222695 0.0054311560 4.6966380876 4.5742737931<br /> <br /> <br /> <br /> 305.00 0.0142715257 0.0052850687 4.7298757363 4.6521815403<br /> <br /> <br /> <br /> 310.00 0.0144218157 0.0051365259 4.7619351485 4.7293532915<br /> <br /> <br /> <br /> :<br /> <br /> <br /> <br /> :<br /> <br /> <br /> <br /> :<br /> <br /> <br /> <br /> ###########################################################################= #################################<br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />
