differences in energies after jobex and (after single point) ridft

Started by yasmeen, May 05, 2011, 12:24:52 PM

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yasmeen

Hi,
I'm using Turbomole 6.3 version.
I'm trying to optimize geometry of manganese porphyrins with different ligands using BP-DFT  method (def-TZVP basis, Ri approx.) and I've found a little bit strange problem with energy level. When after the geometry is optimized, I make a ridft calculation, the energy level is slightly decreased. It happens in both cases – when a single point calculation is made using only obtained geometry with a new control file, and when the control file and all additional files (including alpha and beta) are taken from geometry optimization.
E.g. when E=-2215, 882357, after ridft E=-2215,885735 in both cases. For another molecule : E=-2216,245884, after ridft E=-2216,249449 (using only converged geometry) or E=-2216,248802.

I would appreciate any suggestions where the differences could come from and how to solve this problem.



uwe

Hi,

if you run an energy calculation after a geometry optimization the total energy indeed must not change. Check your ridft output file, it should be only 3 SCF iterations in there until convergence, because you are not just using the optimized coordinates but also the converged orbitals.

You should send your files to the Turbomole support, I guess without looking at your input in detail it is not possible to find out where the problem comes from.

Regards,

Uwe

yasmeen

Hi,
the problem is fixed and the reason is the simplest in the world. I was looking at the wrong value (still I don't know how I did it). So everything is ok - sorry for making trouble.
Best regards