Slater exponents

Slater exponent for the. t type Slater orbitals on atom A and. s orbital Slater exponent for the s type Slater orbitals on atom li. 

The Slater exponents partially listed in the table above are used for all the STO-NG basis sets. The exponents for all the atoms with atomic numbers less than and equal to 54 are available from HyperChem basis function. BAS files. 

The method of many-electron Sturmian basis functions is applied to molecnles. The basis potential is chosen to be the attractive Conlomb potential of the nnclei in the molecnle. When such basis functions are used, the kinetic energy term vanishes from the many-electron secular equation, the matrix representation of the nnclear attraction potential is diagonal, the Slater exponents are automatically optimized, convergence is rapid, and a solution to the many-electron Schrodinger eqeuation, including correlation, is obtained directly, without the use ofthe self-consistent field approximation. 

The Slater exponents of the atomic orbitals are automatically optimized. 

With barriers to internal rotation in C2Hg and H2O2, the exponent optimization noted in Table 2,5 brought about no improvement. Actually, use of optimum exponents for H2O instead of Slater exponents resulted in a worse agreement with experimental results for H2O2, Difficulties in accounting for the barrier to internal rotation in H2O2 are not compatible with the problems of minimum basis set optimization and they will be discussed later. We note it here just to point out... 

One of the most successful methods of calculating nuclear spin coupling constants involves application of SCF perturbation theory and use of the INDO molecular orbital (MO) approximations. (8-17) In most theoretical studies aAB and bAB are taken as empirical parameters, adjusted to give best agreement between theory and experiment. Values of the individual integrals calculated from Slater exponents (14) are given in Table I. 

The one-center Coulomb integrals (/x/x vv) = F v are calculated analytically while the G integrals are taken as parameters. The IP are taken from atomic spectra. After rearranging Eq. (43), the Uss are obtained. A special feature of INDO/S is the use of distance-dependent Slater exponents for the calculation of two-center integrals [55],... 

Calculate the Slater exponent for lithium 2s using Slater s rules and enter this value in cell D 4. 

A particular advantage of the Pople approach (25, 32, 33, 41) to the construction of Gaussian basis sets is the straightforward manner in which Slater s rules carry over to Gaussian theory. The interrelation (25) between a Gaussian exponent, a, and the Slater exponent, f, for a particular orbital in an atom, follows from the identity... 

Therefore, to use a Gaussian set to approximate an atomic orbital, for which the Slater exponent is each Gaussian exponent must be scaled in the form... 

Table 1.6 lists the Hehre, Stewart and Pople sto-3g) Gaussian sets (33) for hydrogenic Is, 2s and 2p orbitals, the minimum basis sets for the atoms of the first short period when scaled with suitable choices for the Slater exponents. 

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