Re: [Towhee-users] Problem calculating heat capacity in Towhee

[William K. <wil...@gm...>]

This requires additional ensemble averages for <H^2> and <U^2> , which is
not currently part of the towhee output. I wonder if Martin may also add
these outputs to the next version of the code.

On 10/21/08, 李晓锋 <kn...@sj...> wrote:
>
>
> One groupmember has checked the subroutines to calculate the heat capacity
> last year and he found that there is a little bug in the source code. So the
> heat capacity in the towhee output is not correct. But I think you can let
> towhee output the H, V, and so on every certain step and then write a small
> script to calculate the heat capacity.
>
> Xiafeng Li
>
> School of Chemistry and Chemical Technology
> Shanghai Jiao Tong University
> 800#, Dongchuan Rd. Shanghai,China, 200240
> ------------------------------
>  *发件人：* William Kennedy
> *发送时间：* 2008-10-21  21:30:38
> *收件人：* mar...@us...
> *抄送：* tow...@li...
> *主题：* [Towhee-users] Problem calculating heat capacity in Towhee
>
> The formula given in the towhee output for calculation of heat capacity
> (T^2<H^2>-<H>^2) does not seem to have correct dimensions. The corrected
> forms suggest:
>
> C_p=(<H^2>-<H>^2)/(T^2*k_b)
>
> C_v=(<U^2>-<U>^2)/(T^2*k_b)
>
> I wonder if anybody had checked on this in the corresponding calculating
> subroutines in the code. Also, I was comparing the experimental values for
> the heat capacity (C_p, C_v) for pure methane with the corresponding values
> obtained from the towhee code and the two values differ significantly. For
> example at T=100(K), P=100(KPa) , C_p= 54.672 (J/K*mol) from experiment and
> C_p= 0.1221E+4 (J/K*mol) from towhee). Any suggestions?
>