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> 4.6966380876??? * 8.314 = 39.048 > (where, Gas constant, R = 8.314 J/(mol K) ) and for Silicon N = 2, so 3N=6 modes > > So, Specific heat, C_v= 38.761 / 3N = 6.5080??? J/(mol K) > > Experimentally the Specific heat, C_v of Si at 25 ??C (~298) is found equal to 9.789 J??mol???1??K???1. > > Can anybody could explain the reason behind this huge error in the calculation of specific heat ? > > Warm Regards > Amit N. Harode > C R Labs INDIA > _______________________________________________ Pw_forum mailing list Pw_forum at pwscf.org http://www.democritos.it/mailman/listinfo/pw_forum -----Inline Attachment Follows----- _______________________________________________ Pw_forum mailing list Pw_forum at pwscf.org http://www.democritos.it/mailman/listinfo/pw_forum _______________________________________________ Pw_forum mailing list Pw_forum at pwscf.org http://www.democritos.it/mailman/listinfo/pw_forum --=_3c2bcaaa63db7e8f797f418158be1bfe Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset="UTF-8" <br /> Dear Prof. Eyvaz Isaev<br /> <br /> Thank your explanations!<br /> <br /> On Tue, 25 May 2010 04:26:33 +0530 wrote<br /> >Hi,<br /> > One can see there is excellent agreement with the experimental data. >So,= the conversion prescribed in F_QHA.f90 is correct. Please check >again exp= erimental data for Si (may be it is in cal/mol/K?).<br /> <br /> > You can note that 4.6966*1.985=3D9.32 cal/mol/K, not too far from >experi= mental data you provided C_v(300K)=3D9.789. Besides, may be >experimental v= alue is C_p, but not C_v.<br /> <br /> I would like to correct a mistake in last post, for Si, C (298 K) =3D 19.7= 89 J.mol^{-1}.K^{-1} (and not 9.789 J.mol^{-1}.K^{-1} ) (Sorry for it.)<br = /> <br /> For Si, C_p - C_v < 0.004 (Ref.:Flubacher et.al, Phil Mag, 4: 39, 273 =E2= =80=94 294)<br /> <br /> Also, from PRB, 50, 14587, C_v {~300} ~ 20 J.mol^{-1}.K^{-1}<br /> <br /> <br /> Regards<br /> Amit N. Harode<br /> <br /> <br /> <br /> <br /> Well, let me add that I have found experimental C_v for Al (Phys. Rev. 162,= 549). From Table II CV(300K)=3D22.91(J/mol/K) and C_v(500K)=3D24.23(J/mol/= K)<br /> <br /> <br /> <br />
