Difference in ahlrich vtz & tzv


Clicked A Few Times
Hello All

I have the following questions:

1) I have to use Ahlrich's TZV for metal atoms and Ahlrich's DZV for ligand atoms. There is one file for ahlrichs_vdz but 2 different ones for TZV: ahlrichs_vtz and ahlrichs_tzv.
Which one of these 2 should be used? What difference is there between the two?

If I mention Cu library Ahlrichs TZV in the input which one of the two would be used?

2) I have another question: Is it possible to use a guess from a lower basis set calculation for a higher basis set in a single point calculation? I have 4 ligand atoms C,H,P & O and I metal = Cu. I want to compute the Total DFT energy using CDFT for a spin constrained calculation with both mult 3 and mult 1. For the larger basis set I have to use Ahlrichs VDZ (for ligand) and VTZ for Cu. However I am getting a little deviation from the earlier reported value for J. Is it possible to use a smaller basis set like 3-21g* for ligand and aldrichs_ptz for Cu and use this as guess for the larger basis set calc.?

3) I also want to know for sure whether a specific calculation performed on NWChem version 4.3 (2005) would differ in final results to those performed on later versions esp. 6.0 and 6.6? Also will the machine it is installed on matter? This is in reference to the CDFT calculation.

Please answer my questions asap. Thanks,

Regards,
Mic


Forum >> NWChem's corner >> General Topics