Re: Dummies in Gaussian
On Tue, 16 Nov 1993, Jack Houser wrote:
> Dear Netters:
>
> I am trying to construct a Z-matrix for Gaussian 90 using two dummy atoms,
> but the program crashes with the message "Too many symbols in
list", or
> something like that. I am using variable names, but they all are spelled
> correctly and none are missing. The only thing I can figure is that the
> id number of the second dummy never appears in the distance column, though
it
> does in the angle and dihedral columns. Does every dummy have to be shown
as
> having some other atom bonded to it (as opposed to its being bonded to
another
> atom), or can you only have one dummy in the Z-matrix? Thanks.
>
> Jack Houser
>
You have to specify an arbitrary distance for connecting the two dummy atoms
(I always use 1.0). Here is an example:
This is a 3,5-difluoroaniline with two dummy atoms used to help define
various angles and bond distances needed to complete an inversion on the
NH2 centre:
%mem=4500000
%chk=90_tmp
# test rhf/6-31g* opt optcyc=40 iop(2/16=1)
Aniline nh2 invert <x2c1n7h7 = opt, lone pair = 90
0 1
x1
x2 x1 1.0
c1 x2 1.0 x1 90.0
c2 c1 c1c2 x2 90.0 x1 x1x2c1c2
c6 c1 c1c2 x2 90.0 x1 -x1x2c1c2
c3 c2 c2c3 c1 c1c2c3 x2 90.0
c5 c6 c2c3 c1 c1c2c3 x2 -90.0
c4 c1 c1c4 x2 90.0 x1 180.0
h2 c2 c2h2 c1 c1c2h2 x2 -90.0
h6 c6 c2h2 c1 c1c2h2 x2 90.0
h3 c3 c3h3 c2 c2c3h3 c1 180.0
h5 c5 c3h3 c6 c2c3h3 c1 180.0
h4 c1 c1h4 x2 90.0 x1 180.0
n7 c1 c1n7 x2 x2c1n7 x1 0.0
h71 n7 n7h7 c1 c1n7h7 x2 x2c1n7h7
h72 n7 n7h7 c1 c1n7h7 x2 -x2c1n7h7
c1c2 1.3927
c2c3 1.3836
c1c4 2.7991
c2h2 1.0765
c3h3 1.0758
c1h4 3.8737
c1n7 1.3972
n7h7 0.9976
c1c2c3 120.3959
c1c2h2 119.5893
c2c3h3 119.1773
x2c1n7 91.9838
c1n7h7 114.1984
x1x2c1c2 120.6366
x2c1n7h7 64.3533
Hope this helps,
Rob
=============================================================================
schurko -x- at -x- ccu.umanitoba.ca Robert Schurko
Chemistry Department
(204)-474-9335 University of Manitoba
Winnipeg, MB, CANADA
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