Re: Energy conversation

From: Alexander A. Vakhrushev (makaveli.lcf_at_gmail.com)
Date: Fri Dec 05 2008 - 23:06:30 CST

Hi Roman, thank you for your help!

The tricks is that I can't use NAMD as a reference for my own
calculations without exact value. So I also found those translations
for calories to Joules, but you see they are different:-) In large
systems they will lead to different conformations after minimization
process in NAMD and self implemented progs. Estimating Coulomb factor
and after test it seems value of 332.0636 is the correct one.

2008/12/6 Roman Petrenko <rpetrenko_at_gmail.com>:
> taken from wiki page http://en.wikipedia.org/wiki/Calorie
>
> 1 cal = 4.1868 J (1 J = 0.23885 calIT) (International Steam Table
> calorie, 1956)
> 1 cal = 4.184 J (1 J = 0.23901 calth) (Thermochemical calorie)
> 1 cal = 4.18580 J (1 J = 0.23890 cal15) (15°C calorie)
>
> as to the factor in coulomb interactions i think you got it right, it
> should be around 332 if the energy is in kcal/mol units.
>
>
> On Fri, Dec 5, 2008 at 8:51 AM, Alexander A. Vakhrushev
> <makaveli.lcf_at_gmail.com> wrote:
>> Hi all!
>>
>> Would you please help, what actual factor should be used to translate
>> NAMD's energy from "ccal*mol^-1" to "kJ*mol^-1"?
>> And what is the constant in Coloumb energy: U=f*q^2/r?
>> Is it
>> 00044 #define COLOUMB 332.0636
>> deffined in common.h?
>>
>> Thank you!
>>
>> --
>> Best regards,
>>
>> Dr. Alexander Vakhrushev
>> Institute of Applied Mechanics
>> Dep. of Mech. and Phys.-Chem.
>> of heterogeneous media
>> UB of Russian Academy of Sciences
>> 34 T. Baramzinoy St.
>> Izhevsk, Russia 426067
>>
>>
>
>
>
> --
> Roman Petrenko.
> Physics Department
> University of Cincinnati
>

-- 
Best regards,
Dr. Alexander Vakhrushev
Institute of Applied Mechanics
Dep. of Mech. and Phys.-Chem.
of heterogeneous media
UB of Russian Academy of Sciences
34 T. Baramzinoy St.
Izhevsk, Russia 426067
----------------------------------
С уважением,
    Вахрушев Александр Александрович
к.ф.-м.н., с.н.с.
Институт прикладной механики
Уральского Отделения
Российской Академии Наук
426067, г. Ижевск
ул. Т. Барамзиной 34
+7(3412)21-45-83

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