TZ basis sets

A TZ basis set for hydrogen (55/35) was expanded with appropriate sets of polarization functions to balance the heavy atom basis. The polarization function exponents were (H) = 1.50, 0.375 and (H) = 1.00. 

At MP2/ECP (TZ basis set augmented with a double set of polarization functions for the valence electrons) from Reference 45. 

Throughout this chapter, unless specified otherwise, STO valence basis sets of triple-C (TZ) quality were used for the actinides Th-Am (54), while valence basis sets used for C and H were of the quality of double-, with 3type polarization functions (DZP) for C and H, respectively. In order to test the effects of different basis sets, we also used at several places the TZ basis sets with d- and /-type or p- and rf-type polarization functions (TZ2P) for C and H. The exponents of the polarization functions were taken from the standard basis sets library of ADF, i.e., (3d) = 2.20, C(4/) = 3.30 for C, and C (2p) = 1.25, C(3rf) = 2.50 for H. 

A double-zeta (DZ) basis set is obtained by replacing each STO of a minimal basis set by two STOs that differ in their orbital exponents ((zeta). (Recall that a single STO is not an accurate representation of an AO use of two STOs gives substantial improvement.) For example, for QHa a double-zeta set consists of two Is STOs on each H, two Is STOs, two 2s STOs, two 2p two 2py, and two 2p STOs on each carbon, for a total of 24 basis functions this is a (4s /2s) basis set. (Recall that we did a double-zeta SCF calculation on He in Section 13.16.) Since each basis function Xr in < i = 2, CriXr has its own independently determined variational coefficient c , the number of variational parameters in a double-zeta-basis-set wave function is twice that in a minimal-basis-set wave function. A triple-zeta (TZ) basis set replaces each STO of a minimal basis set by three STOs that differ in their orbital exponents. 

WsOig]"-, [WjOigf- and [WsOig]"- UV-Vis Several DFT methods/ DZ and TZ basis sets COSMO 88... 

Table 8 Valence Correlation Energies of the Carbon, Oxygen, and Neon Atoms (in millihartrees) from CCSD(T) Calculations with the cc-pV/tZ Basis Sets. The Estimated Valence Correlation Energies of the Atoms are from Ref. 71 (WD)...

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