1

##### Jobex: Structure Optimization and Molecular Dynamics / Re: Optimising the geometry of very large nanoparticles

« Last post by**uwe**on

*November 26, 2020, 12:30:16 PM*»

Hello,

thanks a lot for those really useful tests and findings!

The SCF integral thresholds which are derived from $scfconv settings do take care of the number of basis sets already, and they are also adapted depending on the property which is being calculated. Also the 'diffuseness' can be important and is partly checked.

But it is really unusual to have those problems with the gradients already. 2nd derivatives, NMR, etc. is not unexpected, but gradients...

Is it a very delocalized system? But rocksalts are semiconductors.

The interesting question is: Where do the numerical problems come from? From which part - DFT functional, Exchange, Coulomb, ...?

But to answer that and to potentially find out where to change the defaults, it is necessary to get those contributions separately.

I therefore would like to ask you to send the input files to the support team!

Best Regards,

Uwe

thanks a lot for those really useful tests and findings!

The SCF integral thresholds which are derived from $scfconv settings do take care of the number of basis sets already, and they are also adapted depending on the property which is being calculated. Also the 'diffuseness' can be important and is partly checked.

But it is really unusual to have those problems with the gradients already. 2nd derivatives, NMR, etc. is not unexpected, but gradients...

Is it a very delocalized system? But rocksalts are semiconductors.

The interesting question is: Where do the numerical problems come from? From which part - DFT functional, Exchange, Coulomb, ...?

But to answer that and to potentially find out where to change the defaults, it is necessary to get those contributions separately.

I therefore would like to ask you to send the input files to the support team!

Best Regards,

Uwe