Enthalpy of vaporization calculation in CP2K

[bharat]

Hi Samuel,
It's a semiempirical calculation. I does not have any functional forms like 
GGA or hybrid. Calculation is correct because I was able to reproduce other 
properties. Isn't internal energy "Total energy" in CP2K? if not how do I 
calculate internal energy from cp2k results?

Thanks.

Bharat

On Monday, December 8, 2014 3:52:56 AM UTC-5, Samuel Andermatt wrote:
>
> 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 
>>>
>>>
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