$DAMPGS group (relevant if $DAMP was given)
This is a free-format, line by line input group that
sets the initial values damping functions used to screen
the multipole expansion. A check run may be helpful in
listing the names of the expansion points that are chosen
by MAKEFP jobs. Very often the input group contains only
type -1- lines, and only in its second form.
----------------------------------------------------------
-1-
or =
This line gives the name of the expansion point, and how
many terms are in the damping function (always 1 at
present). The second form of this line lets you equate the
current point to some previous point's values in $DAMPGS,
skipping line -2-.
----------------------------------------------------------
-2-
The linear coefficient (usually 1.0) and exponent of this
term in the damping function. Repeat -2- times.
If not given, the starting exponent for atoms is 2.0, and
for bond midpoints, 4.0.
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An example, for water, enforcing equivalent points, is:
$dampgs or much more simply,
O1 1 since the left is default exponents,
1.0 2.0 $dampgs
H2 1 H3=H2
1.0 2.0 BO31=BO21
H3=H2 $end
BO21 1
1.0 4.0
BO31=BO21 The "BO" is short for bond midpoint.
$end
39 lines are written.
Edited by Shiro KOSEKI on Tue May 17 15:19:38 2022.