ECPs - Am I doing it right?
Clicked A Few Times
10:11:13 AM PST - Wed, Nov 21st 2012
Hi All

I submitted a job (Ru(CO)5) with the B3LYP functional and the following basis & ECP sections:

basis
  • library 6-311++G** except Ru
Ru library "Stuttgart RSC 1997 ECP"
end

ecp
Ru library "Stuttgart RSC 1997 ECP"
end

Is "Stuttgart RSC 1997 ECP" equivalent to SDD (MWB28) that is the default for Ru in Gaussian?

I have a small discrepancy in the DFT energies.

NWChem: Total DFT energy = -661.868406099492
Gaussian: SCF Done: E(RB3LYP) = -661.860135118 A.U. after 1 cycles

Did I do it right?

Thanks in advance.

Forum Vet
10:18:06 AM PST - Wed, Nov 21st 2012
The input is correct.

To the question if the basis sets and ECPs are the same between the codes, I do not know for sure. All I can recommend is you check the output of both codes and compare the basis sets and ECPs.

But, before you do that I would carefully check for both codes if they are both using cartesian or spherical basis sets. Comparing results from codes where one is running with a cartesian basis set and the other with a spherical basis set could lead to these differences. Also, are you using the exact same geometries when comparing, and also are the DFT grids and DFT functionals the same.

Bert


Quote:Andrew.yeung Nov 21st 5:11 pm
Hi All

I submitted a job (Ru(CO)5) with the B3LYP functional and the following basis & ECP sections:

basis
  • library 6-311++G** except Ru
Ru library "Stuttgart RSC 1997 ECP"
end

ecp
Ru library "Stuttgart RSC 1997 ECP"
end

Is "Stuttgart RSC 1997 ECP" equivalent to SDD (MWB28) that is the default for Ru in Gaussian?

I have a small discrepancy in the DFT energies.

NWChem: Total DFT energy = -661.868406099492
Gaussian: SCF Done: E(RB3LYP) = -661.860135118 A.U. after 1 cycles

Did I do it right?

Thanks in advance.

Clicked A Few Times
11:17:22 AM PST - Wed, Nov 21st 2012
Thanks for your comments.

I think the problem is how the SDD basis set is defined in Gaussian vs. the Basis Set Library. Using "Stuttgart RSC 1997 ECP" in Gaussian and NWChem, I did a single point energy calculation of a given geometry. These are the results:

NWChem: Total DFT energy = -661.868398129143
Gaussian: SCF Done: E(RB3LYP) = -661.868399501 A.U. after 13 cycles


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