Insight: archive file number ??

Andras Szilagyi szia at
Wed Mar 24 10:14:58 EST 1999

On Wed, 24 Mar 1999 13:07:00 +0000, Benny Lo <benny at> wrote:

>Does anyone know why? What's the significance of the figure after
>"archive file number". I couldn't find this in the extremely brief
>Discover manual.

Archive files can contain several segments. Each segment can contain one
coordinate set. In this way, you can store several coordinate sets (eg.
several snapshots of a molecular dynamics simulation) in a single *.arc
file. The number after "archive file number" tells Discover to which
segment in the given archive file it should write the coordinate set. Of
course, it makes not much sense to write the coordinates to segment 2 if
segment 1 has never been written. When you read in the coordinates into
Insight using the Get Molecule command, you can enter the segment number
from which Insight should load the coordinate set. The default for this
number is 1, so if you try to read in an archive file that contains no
segment #1 because you only wrote data to segment 2 then all sorts of
curious things might happen.

So if you want to write the coordinate sets into separate archive files
then you should use "archive file number 1" for all files. But you could
as well store all coordinate sets into one single archive file; in that
case you have to start with "archive file number 1" and then increment
the number after "archive file number" for each set, but the same file
name should be used in each case.

By the way, this is clearly documented in the Discover manual, you should
find it if you study the manuals carefully.

Andras Szilagyi, PhD (szia at
Institute of Enzymology, Hungarian Academy of Sciences
Karolina ut 29., H-1113 Budapest, HUNGARY
Fax: +36 1 466 5465, phone: +36 1 466 5633

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