(c) 2017, Marcus Elstner, Karlsruher Institut für Technologie
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SPECIFIC PURPOSE PARAMETER SETS

name   requires    elements    
nhmod       mio       N-H

short description
NHmod for stronger NH binding
        

detailed description:

In previous studies [JACS04,TCA06] consistent errors of about
10 kcal/mol were found specifically for proton affinities of sp3
hybridized nitrogen atoms. Therefore, a modified parameter set
“NHmod” was introduced in which the N-H repulsive potential
was shifted to correct for these errors. However, since sp2
hybridized nitrogen atoms seem to be described correctly, this
correction has only to be applied for a certain electronic
configuration of N. Therefore, similar to the situation in force
fields, different “atom types” for N have to be introduced at the
moment, which clearly limits DFTB’s applicability since these
atom types are not allowed to change during a reaction.
For benchmarks see [JPCA07,JCTC11].
Geometrical properties are very similar to the original mio N-H parameter set.

RELEVANT PUBLICATIONS
[JACS04] J. Am. Chem. Soc. 2004, 126, 14668-14677.
[TCA06]  Theor. Chem. Acc. 2006, 116, 316-325.
[JPCA07] J. Phys. Chem. A 2007, 111, 10861-10873.
[JCTC2011]    J. Chem. Theory Comput. 2011,7,931-948.

REQUIRED REFERENCES
N-H-mod       [JACS04] J. Am. Chem. Soc. 2004, 126, 14668-14677.