Are non-selfconsistend DFT optimizations possible?

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Hi All,

There is an interesting possibility to run DFT non-selfconsistently, using density from another, previous DFT run. It takes two dft ... end group, the last one with 'noscf' keyword, and two 'task dft energy' computations. The gradient also seem to be available -- but how to do optimizations? If I run 'task dft optimize', it would probably refer to the last dft .. end group only? Is there a way?

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With best regards,
Grigory Shamov
Chemistry,
University of Manitoba

  • Niri Forum:Admin, Forum:Mod, NWChemDeveloper, bureaucrat, sysop
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Hi Grigory,

Give it a try and let me know. I implemented the noscf keyword to get non-selfconsistent energies based on vectors from a different calculation (xc functional) but I didn't check optimizations. Try the following in your input.

dft
xc some_functional_1
end
task dft energy

dft
noscf
xc some_functional_2
end
task dft optimize

This should do an optimize based on the second_functional

Best regards,
-Niri Govind

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tried
Dear Niri,

Thank you for the reply. I've tried it, it works but optimizes wrt only the last DFT group. I.e., orbitals are always taken from the first geometry.

What would i like to do is actally optimize with orbitals relaxed with DFT1 then non-self-consistently done with DFT2, for each geometry point. Seems not to pass through the syntax though!

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With best regards,
Grigory Shamov

  • Niri Forum:Admin, Forum:Mod, NWChemDeveloper, bureaucrat, sysop
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Hi Grigory,

As I mentioned in my earlier message I didn't intend noscf for geometry optimizations but I appreciate the value in this Harris functional like approach. I'll consider this and try to implement it as soon as time permits.

Best,
-Niri


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