| 11:28:29 AM PST - Fri, Nov 25th 2011 |
|
Hello. I'm using nwchem to calculate binding energies of small molecules on an transition metal clusters. As some of these clusters are very large (particularly in comparison to the adsorbates) it would be useful if I could use the KS-orbitals/densities from the previously calculated bare cluster when starting the calculation of the cluster+adsorbate system. This should speed things up a bit, particularly on the first SCF cycle since whatever the electronic structure of the bare cluster was will be a better initial guess than the usual atomic density. I would have hoped that if the atoms were all in the same order in the input file, it would have sufficed to do the following:
start
echo
memory 4600 mb
geometry bridge1 noautoz noautosym
Pd 2.398765852 0 1.388678926
Pd 0 0 2.776431822
Pd 0.744233156 -2.228737442 1.472444413
Pd 0 0 0
H 0.760264707 0.749454007 1.44434155
H 1.38625867 -1.0868673 0.378189346
H -0.569927871 -0.01838549 -1.060303572
H -0.566033065 0.721597247 -1.057081848
end
basis set info etc....
dft
mult 1
xc PBE0
grid fine
vectors input bare_Pd4.movecs output nwchem.movecs
convergence energy 1.000000E-07
convergence density 1.000000E-05
convergence gradient 1E-05
iterations 1600
mulliken
end
task dft optimize
and that this would use the previously calculated density with just the usual atomic density guess for the
hydrogen atoms.
However, the output file indicates that the old .movecs were not used:
Either an incorrect movecs file was specified, or linear dependence has changed, or the basis name was changed.
Loading old vectors from job with title :
Load of old vectors failed. Forcing atomic density guess
It seems like there MUST be a way of doing this. Also, if there is a way, can someone please explain if anything special needs to be done if the total spin state of the system changes (say if it's O2 instead of H2 and total system goes from a triplet to a quintet).
Thanks for any help you can give.
|