Enthalpy of vaporization calculation in CP2K

[Samuel Andermatt]

You will need to post your input and output files. Do you do GGA or hybrid 
calculations, how do you account for the vdW forces?

On Friday, December 5, 2014 4:17:45 PM UTC+1, bharat wrote:
>
> Hello,
> This is friendly reminder. Any suggestions?
>
> Bharat
>
> On Wednesday, December 3, 2014 12:56:10 PM UTC-5, bharat wrote:
>>
>> Hello Experts,
>>
>> I am trying to reproduce Enthalpy of vaporization using PM3.
>> Here are my calculation: 
>> (I took Total energy value from CP2K output file as an Internal energy, 
>> average is calculated over the MD. Experimental density is used for the 
>> constant volume for both liquid and vapor calculation). Am I taking correct 
>> energy value for internal energy? 
>>
>> U_vapor(Avg) = -20797.3 eV 
>> U_liquid(Avg) = -20802.9 eV
>>
>> Delta_U = 5.6 eV 
>> I divided with 64 (# of water molecules) and converted to kcal/mol
>> = 2.02 kcal/mol
>>
>> I got the half value (reported value is 4.00 kcal/mol in G. Murdachaew et 
>> al. J. Phys. Chem. A 115, 6046 (2011)). Because of this value, I got only 
>> ~2.60 kcal/mol (RT= ~0.60 kcal/mol) of enthalpy of vaporization (Delta_H = 
>> delta_U + RT). 
>>
>> Can anyone please tell me where I am doing wrong? Where is the factor 2 
>> missing?
>>
>> Thank you.
>>
>> Bharat 
>>
>>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20141208/fe06e384/attachment.htm>