task gradient failed


Clicked A Few Times
Hi...I am new to nwchem ...As I am trying to do task SCF with tweleve Au atoms with one Cr in center...but getting an error in the end of the compilation of the input file i.e



scf_gradient: scf energy failed        0
------------------------------------------------------------------------
This type of error is most commonly associated with calculations not reaching convergence criteria
------------------------------------------------------------------------
For more information see the NWChem manual at http://nwchemgit.github.io/index.php/NWChem_Documentation


As my input file is

title "Au-Cr scf geometry optimization"
charge 0
memory total 800 heap 200 stack 200 global 400 mb
geometry units angstoms print xyz autosym

Au 22.76000 -17.51900 -23.53900
Au 22.79300 -17.55300 -17.96000
Au 24.18900 -19.50800 -19.39000
Au 21.36500 -15.56400 -22.10800
Au 24.32500 -15.57700 -21.97200
Au 21.22800 -19.49500 -19.52600
Au 20.40600 -18.32200 -21.94800
Au 25.14800 -16.75100 -19.55000
Au 25.10600 -18.42900 -21.95700
Au 20.44900 -16.64400 -19.54200
Au 22.75100 -15.05800 -19.53100
Au 22.80300 -20.01500 -21.96700
Cr 22.77700 -17.53600 -20.75000
end
basis
Cr library cc-pvdz
Au library lanl2dz_ecp
end
ecp
Au library lanl2dz_ecp
end
scf
thresh 1.0e-4
level nr 0
maxiter 50
end
task scf optimize

Please help me to solve error.....
Thanks in advance
Regards
Satvinder

Forum Vet
Please submit the output file
Thanks

Clicked A Few Times
hello .. thanx alot for your reply.... here is some problem in sending the output file... how can i attach my output file here ?

Forum Regular
Hi Satvinder,

In this case the problem is that the SCF calculation for the energy did not converge. The calculation seems to be heading in the right direction but it is slow getting there. In any case when the gradient calculation fails it is often (not always) associated the SCF part not reaching convergence. So a good practice is to search from the end of the output file backwards for

    Total SCF

in the case of a Hartree-Fock calculation or

    Total DFT

in the case of a DFT calculation and see why the SCF step terminated. If something unexpected happened it will usually say that.

Best wishes, Huub


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