Huzinaga basis sets

The double zeta basis sets, such as the Dunning-Huzinaga basis set (D95), form all molecular orbitals from linear combinations of two sizes of functions for each atomic orbital. Similarly, triple split valence basis sets, like 6-3IIG, use three sizes of contracted functions for each orbital-type. 

The starting point is our previously performed calculations [3] using the Huzinaga basis set [20] (9s) for Be and (4s) for H, triple-zeta contracted, supplemented by the three 2p orbitals proposed for Be by Ahlrichs and Taylor [21] with exponents equal to 1.2, 0.3 and 0.05 respectively. This initial basis set, noted I, includes one s-type bond-function the exponent of which is equal to 0.5647. Several sets of diffuse orbitals have then been added to this basis I. Their corresponding exponents were determined by downward extrapolation from the valence basis set, using the Raffenetti [22] and Ahlrichs [21] procedure. Three supplementary basis sets noted II, III and IV containing respectively one, two and three... 

G and Huzinaga basis sets used for K, Rb and Cs, 6-31+G and 6-31+G on C used for C3H5. 6-31+G. Number of imaginary frequencies is given in parentheses (1) a transition state (2) a second-order saddle point. 

Before leaving this topic, it should be mentioned that, in addition to the (Pople) basis sets discussed so far, there are others as well. The more popular ones include the Dunning-Huzinaga basis sets, correlation consistent basis sets, etc. These functions will not be described here. 

Modified NDDO Models 85 r 5.4.2 Dunning-Huzinaga Basis Sets 160... 

Table 5.1 The Huzinaga basis sets (45) for the calculation of the energy of the helium atom. The Slater exponent is set equal to 1.0 in any calculation.

For the nM+CrCl system the density functional theory (DFT) method with the B3LYP hybrid functional and the Huzinaga basis set were used, with the addition of two polarization r/-functions to the mini basis sets of all atoms except for potassium and also a single polarization/-function and a single diffuse p-function to the basis set of the chlorine atoms. In addition, for several structures, the act values were calculated using the MP2 method with the same basis set, as the principal calculations, but for the geometry that was obtained in advance using the unrestricted Hartree-Fock method with a somewhat lesser basis set (without addition of the polarization/-functions to the basis set of chlorine atoms). 

Doubles, doubly excited configurations, 100 Douglas-Kroll transformation, 215 DREIDING force field, 40 Dummy atom, 37, 417 Dunning-Huzinaga basis sets, 160 Dynamic properties, 235 Dynamical electron correlation, 118... 

Using the method of least squares, we obtain the following parameters for the (9s5p) Huzinaga basis set ... 

Of the Dunning-Huzinaga basis sets, the [4s2 p set has been particularly popular. This double-zeta (DZ) basis set, in which there are two contracted functions for each occupied AO, represents... 

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