. Author manuscript; available in PMC: 2009 Apr 6.

Published in final edited form as: J Chem Theory Comput. 2008;4(12):2067–2084. doi: 10.1021/ct800330d

TABLE I.

Different sets of parameterizations of the SCC-DFTB approach for phosphate^a

Notation^b	Reference data^c	$U_{P, O, C, H}^{d}$	D₀,Г₀,Q₀
	Second-order parameterization
2^nd-order	13 small molecules (see main text)	—	—

	Third-order parameterizations
3^rd-order	—	−0.07, −0.17, −0.16, −0.16	—
SCC-DFTBPA	Proton affinity, 18 P-compounds	−0.07, −0.20, −0.22, −0.23	−0.06, 17.9, 0.86
Mix-optimized	Proton affinities, 5 P- and 11 non-P compounds	−0.10, −0.15, −0.24, −0.15	−0.08 37.5, 0.83
SCC-DFTBPR	37 phosphate reaction energetics	−0.07, −0.22, −0.24, −0.08	−0.09, 16.1, 0.75

$U_{α}^{d}$ is the Hubbard derivative defined in Eq.3; D₀,Г₀,Q₀ are Gaussian parameters defined in Eq.4.

The notations are used in all tables.

“P-compounds” indicate phosphorus containing compounds; “non-P compounds” indicate compounds that do not contain phosphorus. For the list of compounds, see Table 3 and Table 4.