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---------------------------
$Id: README  2007-07-9 Guishan Zheng $
$URL: $

The set has been developed for organic molecules including O, N, C, H
with first row transition metal elements Sc, Ti, Fe, Co, and Ni.
Tests for molecules containing atomic pairs between H/C/N/O and Sc/Ti/Fe/Co/Ni
are published in  JCTC07 paper.

The current parameters works quite well for geometries, from which the bond lengths
usualy differ from B3LYP/SDD+6-31G* (SDD for TM elements, 6-31G* for O, N, C, H)  at 
the accuracy level of 0.06A-0.1A on average while the bond angles differ by about 
10-20 degree. The reaction energy values predicted by the current open-shell DFTB code 
on average differ about 15 Kcal/mol. The spin splitting energy is often qualitatively 
correct but the absolute value can be off by as large as 30-50 kcal/mol. In general, 
the energetics predicted by DFTB has to be taken with causion and needs more thorough 
tests for molecules that contain these parameterized transition metal elements.

For more detailed information about the set of parameter performance, pls refer to 
the paper JCTC07.


Relevant Publications
---------------------

[JCTC07] Zheng, G.; Witek, H. A.; Bobadova-Parvanova, P.; Irle, S.; Musaev, D. G.; Prabhakar, R.; Morokuma, K.; Lundberg, M.; Elstner, M.; Kohler, C.; Frauenheim, T.  J. Chem. Theory and Comput.,3(4),1349-136 (2007).


Required references
-------------------
[JCTC07] Zheng, G.; Witek, H. A.; Bobadova-Parvanova, P.; Irle, S.; Musaev, D. G.; Prabhakar, R.; Morokuma, K.; Lundberg, M.; Elstner, M.; Kohler, C.; Frauenheim, T.  J. Chem. Theory and Comput.,3(4),1349-136 (2007).

