Strange/unexpected behaviour when running dft job for propane(C3H8)
Clicked A Few Times
12:18:46 PM PST - Mon, Feb 17th 2020
Dear All

I have run into a strange behaviour with the following input
propane.nw

Contents

==

memory stack 1500 mb heap 1000 mb global 1000 mb
start propane
geometry units angstrom
symmetry c2v
load propane.xyz
end
basis
  • library 3-21g
end
dft
XC slater pw91lda

 vectors output propane.movecs
end
task dft
dplot 
 TITLE DENSITY

 vectors propane.movecs

 LimitXYZ units bohr

 -6.0	6.0 200

 -6.0  6.0 200

 -6.0  6.0 200

 spin total

 gaussian

 output density.cube
end
task dplot

==

with the xyz file
propane.xyz

=

11
propane
C 0.0000 0.5863 0.0000
C 1.2681 -0.2626 0.0000
C 1.2681 -0.2626 0.0000
H 0.0000 1.2449 0.8760
H -0.0003 1.2453 -0.8758
H -2.1576 0.3743 0.0000
H 2.1576 0.3743 0.0000
H -1.3271 -0.9014 0.8800
H -1.3271 -0.9014 -0.8800
H 1.3271 -0.9014 -0.8800
H 1.3272 -0.9014 0.8800
=

running nwchem with the above input
fails in a strange way
the autoz procedure arrives at a species with 22 atoms!
the output is to big to include
the version of nwchem is 6.8.1-5
any assistance will be appreciated.

Regards

Moritz

Forum Vet
10:54:02 AM PST - Tue, Feb 18th 2020
Moritiz.
please
1) delete the symmetry c2v line from your input file
and
2)
atom 2 and 3 of your xyz file have the very same coordinates
C 1.2681 -0.2626 0.0000

C 1.2681 -0.2626 0.0000
You might to change the x coordinate of atom number 3

C 0.0000 0.5863 0.0000
C 1.2681 -0.2626 0.0000
C -1.2681 -0.2626 0.0000
H 0.0000 1.2449 0.8760
H -0.0003 1.2453 -0.8758
H -2.1576 0.3743 0.0000
H 2.1576 0.3743 0.0000
H -1.3271 -0.9014 0.8800
H -1.3271 -0.9014 -0.8800
H 1.3271 -0.9014 -0.8800
H 1.3272 -0.9014 0.8800

Clicked A Few Times
3:58:06 AM PST - Wed, Feb 19th 2020
Thank you
I had discovered the identical coordinates yesterday and
fixed them. I also received the symmetry directive.
Now NWChem runs!

Regards

Moritz


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