[Pw_forum] problem to convert Cv (R) to Cv(in J/mol.K)

[Stefano de Gironcoli]

Dear Bramha Prasad Pandey,
  the question rather seams to me how is it that your phonon DOS 
normalization is zero...
  this means that the code thinks your system has zero atoms.
stefano


On 02.02.2012 11:40, bramha pandey wrote:
> Sorry to disturbing all of you.
>  But Really i need your's help to understand the the following
> results. Here i am attaching some more information which is obtained
> through the F_QHA.X code.
>
> # Zero vibration energy:      0.0000000005  (Ry/cell)
> # Phonon DOS norm      :      0.000000      ! 3N for check purpose, N
> number of atoms in the unit cell
> # 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
> 
> ############################################################################################################
>     5.00      0.0000000005      0.0000000005           0.0000000000
>       0.0000000000
>    10.00      0.0000000005      0.0000000005           0.0000000000
>       0.0000000000
>    15.00      0.0000000005      0.0000000005           0.0000000001
>       0.0000000000
>    20.00      0.0000000005      0.0000000005           0.0000000002
>       0.0000000001
>    25.00      0.0000000005      0.0000000005           0.0000000004
>       0.0000000001
>    30.00      0.0000000005      0.0000000005           0.0000000010
>       0.0000000002
>    35.00      0.0000000005      0.0000000005           0.0000000020
>       0.0000000005
>    40.00      0.0000000005      0.0000000005           0.0000000036
>       0.0000000008
>    45.00      0.0000000005      0.0000000005           0.0000000059
>       0.0000000014
>    50.00      0.0000000005      0.0000000005           0.0000000090
>       0.0000000021
>    55.00      0.0000000005      0.0000000005           0.0000000128
>       0.0000000032
>    60.00      0.0000000005      0.0000000005           0.0000000172
>       0.0000000045
>    65.00      0.0000000005      0.0000000005           0.0000000223
>       0.0000000060
>    70.00      0.0000000006      0.0000000005           0.0000000278
>       0.0000000079
>    75.00      0.0000000006      0.0000000005           0.0000000338
>       0.0000000100
>    80.00      0.0000000006      0.0000000005           0.0000000402
>       0.0000000124
>    85.00      0.0000000006      0.0000000005           0.0000000468
>       0.0000000150
>    90.00      0.0000000006      0.0000000005           0.0000000537
>       0.0000000179
>    95.00      0.0000000006      0.0000000005           0.0000000607
>       0.0000000210
>
> Now sir question remain same how i will get the Cv value in J/Mol.K 
> from R.?
>
> Your valuable help is needed to me.
>
> On Wed, Feb 1, 2012 at 9:54 PM, bramha pandey
> <pandey.bramha at gmail.com> wrote:
>>
>>
>> Hi..Dear  QE users
>>
>> I have a problem to calculate the Cv value in J/mol.K from Cv(R gas 
>> constant). At 300K, the value of Cv is  0.0000002506 . I multiplied  
>> 0.0000002506  by 3NR(3*2*8.314) which comes 1.25*10^-5 which was very 
>> less compare to experimental Cv value.
>>
>> Please someone help me.
>> Thanks in advanced for your kind help.
>> --
>> Thanks and Regards
>> Bramha Prasad Pandey
>> Assistant Professor (Electronics and Communication Engg)
>> GLA Group of Institutions, Mathura.
>> Ph. No. 08954143009
>> email id pandey.bramha at gmail.com
>>             bpglaitm at yahoo.co.in