Subject: Lebedev again

From: Andrew Horsfield <[email-masked]>
Date: Tue, 7 Mar 2000 14:00:12 +0000 (GMT)

Hi,

Having had some time to think about the Lebedev tables I received
following an earlier posting, I am now struck by how wide the spacings are
between different meshes. By this I mean that tables exist for (say) l = 3
(6), l = 5 (14), l = 7 (26), l = 9 (38), l = 11 (50), but then nothing
more until l = 15 (86), where l is the maximum angular monetum that can be
integrated, and the number in brackets is the number of points. I have
checked several sources, and everyone does something similar. Is there a
reason for this apart from the inconvenience of having to type in multiple
tables (like you need to double the number of points to get an extra digit
of accuracy)?

Cheers,

Andrew

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From: Christoph van Wüllen <[email-masked]>
Date: Tue, 7 Mar 2000 18:49:26 +0100

>tables (like you need to double the number of points to get an extra digit
... Lebedev considers only grids with octahedral symmetry, so adding 
a grid point which is not on too many symmetry elements has many 
brothers and sisters on equivalent positions. Furthermore, not all 
grids theoretically possible are numerically useful (i.e. usually one 
does not want grids with negative weights).
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