Subject: Gaussian 94 DFT & Opt Problems.

From: "Nathan A. Baker" <[email-masked]>
Date: Mon, 21 Jul 1997 13:52:47 -0700 (PDT)

Hi -- I have encountered several strange errors in Gaussian 94 which I 
was wondering if anyone else may have encountered and perhaps fixed.

First, when performing BPW91 DFT calculations, I often receive a 
"Spurious electron density" error which is not rectified by switching SCF 
methods.  Often this happens in potential energy scans, where one 
structure will give an error while a closely related structure will 
converge without difficulty. 

Second, during geometry optimizations with frozen redundant internal 
coordinates, Gaussian will crash without *any* error message wahtsoever.  
I'm running the package on a Power Challenge system with a very large 
memory limit (.5 Gb) so, I'm fairly sure this crash is not due to memory 
limitations even thought I'm using a big (~20 atoms) molecule with lots 
of added, frozen internal coordinates.

Finally, (this is moer of a question) why does Gaussian ignore the 
frozen redundant coordinates in the followin .COM file? :

%chk=output.chk
#BPW91/6-311+G(d,p) Opt=AddRedundant Test

A Title

0 1
Cartesian Coordinates
(also tried it with Z-matrix)

1 0 0.96 F

It does not freeze the distance between atoms 1 and 0 at 0.96 A during 
the optimization.

Thanks for your help!

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Nathan Baker * [email-masked]

Objects in Mir are closer than they appear.
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