Author Topic: DFT-D frequency calculations with aoforce or numforce  (Read 7612 times)

Stefan

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DFT-D frequency calculations with aoforce or numforce
« on: September 09, 2008, 07:07:54 PM »
Hello,

I have carried out a frequency calculation with aoforce of a Argon dimer with BP86 and BP86-D at the same geometry. For both calculations with aoforce I obtained the same frequencies. This is in opposite to the numforce calculations, where I find differences between both calculations, see below:
BP86 (aoforce): 42.05
BP86-D (aoforce): 42.05
BP86 (numforce): 31.46
BP86-D (numforce): 25.93
Does aoforce not support frequency calculations with DFT-D? However, I find no information in the output of numforce if numforce has employed the DFT-D approach. Can I trust the results of numforce?

Best regards, Stefan   
 

uwe

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Re: DFT-D frequency calculations with aoforce or numforce
« Reply #1 on: September 10, 2008, 10:55:27 AM »
Hi,

DFT-D does not work with aoforce. aoforce uses the molecular orbitals from DFT-D runs, but does not contain itself the DFT-D contribution.

NumForce on the other hand just needs energy and gradients which both have DFT-D implemented, so the NumForce results should be o.k.

Regards,

Uwe

Stefan

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Re: DFT-D frequency calculations with aoforce or numforce
« Reply #2 on: September 10, 2008, 01:36:25 PM »
Thank you.

Best regards, Stefan

jbaltrus

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Re: DFT-D frequency calculations with aoforce or numforce
« Reply #3 on: June 07, 2009, 06:20:22 AM »
Has DFT-D been implemented into aoforce in the latest version? Is it wrong to optimize geometry with DFT-D and calculate aoforce without DFT-D? Would it result in negative frequencies or some other inaccurate results?

JOnas

uwe

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Re: DFT-D frequency calculations with aoforce or numforce
« Reply #4 on: June 08, 2009, 09:44:24 AM »
Hi,

DFT-D has been added to aoforce in Turbomole version 6.0.

Regards,

Uwe