Subject: Units Conversion

From: <[email-masked]>
Date: Thu, 7 Dec 95 15:38:10 EST

Regarding the recent inquiry on units conversion,
> Could anyone come up with reasonable accuracy (at least 6 significant
> figures) for
>
> Hartrees to Joules
> Calories to Joules
> Bohr     to Angstrom
>
> Non of my texts even have the definition of a Hartree.
>
> Thanks in advance
>
> Alex
>
> +--------------------------------------------------+
> |Alternate E-mail [email-masked]            |
> |www home @ http://www.bath.ac.uk/~chpajt/home.html|
> +--------------------------------------------------+
     I can recommend a WWWeb site which will carry out such 
conversions interactively:

http://www.chemie.fu-berlin.de/chemistry/general/units.html

     Instructions are given in English and German, but it is 
simple to use.  Submitting the requested conversion queries to 
this resource gave the following answers.

1 hartree = 4.359748e-18 joule
1 calorie = 4.1868 joule  (fewer than the requested six 
                           significant figures)
1 bohrradius = 0.5291772 angstrom

     This server is often busy, so reference to a manual will 
often provide the answer quicker.

---

From: [email-masked] (Hinsen Konrad)
Date: Sun, 10 Dec 1995 09:25:18 -0500

...

My recommendation for people who have to deal with unit conversions
often is to get a copy of GNU-Calc, a free calculator add-on for the
GNU-Emacs editor. Among other useful features (ranging from matrix
computations to graphics, and including even elemetary symbolic
calculations) it has a very flexible unit conversion system that
lets you even complicated units easily. It can be found wherever
you can get GNU software.

Because 4.1868 J is exact - by definition.

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