Subject: Re: CCL:Units Conversion

From: <[email-masked]>
Date: Tue, 12 Dec 1995 13:00:51 +0100 (NFT)

As far as I know 1 Angstrom IS exactly 10^-10 m. The crystallographic unit
(X untit) deviates from it because in the old time people used to determine
the actual value of an Angstrom using some (cesium-oxid?) crystall of 
known crystallographyc structure, known density, the Avogadro number etc.
Then the density was corrected, so all data obtained through the callibration
mentioned, which were given in "Angstroms", need a slight correction.

Ceterum censeo: 

                 1 Angstrom = 10^-10 m, EXACTLY.

Regards,

I.M.

---

From: TOPPER ROBERT <[email-masked]>
Date: Tue, 12 Dec 1995 08:59:53 -0500

>                  1 Angstrom = 10^-10 m, EXACTLY.

Oh, absolutely. I guess, this being cyberspace, you couldn't see
that my tongue was placed firmly in my cheek when I said that...
the "crystallographic angstrom" is, for this reason, symbolized
with an asterix (*) after the A. 

best, rqt

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