Orbital basis sets for

BasisE ib This is a library file whichcontains gaussian atomic orbital basis sets for Hydrogen - Neon. The basis sets available to choose from are ... 

Absar, Reduced Hamiltonian orbitals. 11. Optimal orbital basis sets for the many-electron... 

The orbital basis set for oxygen [33] is 9s/5p contracted to As/2p according to a same-orbitals-for-different-spins atomic calculation using the appropriate... 

In this contribution we have reviewed the applicability, accuracy and computational efficiency of the local spin density functional approach to the chemistry of transition metal complexes and clusters using a linear combination of Gaussian-type orbital basis set for the calculation of electronic structures, ground state geometries and vibrational properties. 

The DFT dipole moments are often significantly in error, by amounts comparable to the errors for the conventional ab initio procedures. These discrepancies are at least partially due to the deficiencies in the 6-31G(d) orbital basis set. For the lone-pair molecules NH3, H2O and HF, theoretical dipole moments are too large by almost all methods. The theoretical values for... 

Figure 4. Hybrid atomic orbital basis set for the forming bonds, p "lone pair" on the nitrone nitrogen atom (Nip) and CN n bond conjugated with the forming bonds in the endo and exo TSs.

Blaudeau, J.-R, Brozell, S.R., Matsika, S., Zhang, Z., Pitzer, R.M. Atomic orbital basis sets for use with effective core potentials, Int. J. Quantum Chem. 2000, 77, 516. 

BauschUcher, C.W. Jr. Large atomic natural orbital basis sets for the first transition row atoms, Theor. Chim. Acta 1995,92, 183. 

The Chemical Hamiltonian Approach uses the atomic orbital basis set for the definition of an atomic partition of the Hamiltonian operator. An atomic subsystem of a molecule consists of a nucleus and the set of basis functions centered on it. Accordingly, the partition of the finite basis set corresponds to the physical partition of a molecule into atomic subsystems. This raises the problem of non-orthogonality of the basis functions belonging to the different subsystems (atoms, in the present case) and also the problem of basis set superposition error (BSSE), which is a consequence of the finiteness of the basis set [46]. 

H. Basch, C. J. Hornback, and J. W. Moskowitz,/. Chem. Phys., SI, 1311 (1969). Gaussian-Orbital Basis Sets for First Row Transition-Metal Atoms. 

Rods B, Lindh R, Malmquist PA, Veryazov V, Widmark PO, Borin AC. New Relativistic Atomic Natural Orbital Basis Set for Lanthanides Atoms with Applications to Ce Diatom and LuFs. J Phys A. 2008 112 11431. 

Flehre W J, Ditchfieid R and Popie J A 1972 Self-consistent molecular-orbital methods XII. Further extension of Gaussian-type basis sets for use in molecular orbital studies of organic molecules J. Chem. Phys. 56 2257-61 Flariharan P C and Popie J A 1973 The influence of polarization functions on molecular orbital hydrogenation energies Theoret. Chim. Acta. 28 213-22... 

Krishnan R, Binkley J S, Seeger R and Popie J A 1980 Self-consistent molecular orbital methods XX. A basis set for correlated wave functions J. Chem. Phys. 72 650-4... 

This, the well-known Hellmann-Feynman theorem [128,129], can then be used for the calculation of the first derivatives. In nonnal situations, however, the use of an incomplete atom-centered (e.g., atomic orbital) basis set means that further terms, known as Pulay forces, must also be considered [130]. 

Because th e calculation of m n Iti-ceiiter in tegrals that are in evitable for ah iniiio method is very difficult and time-con sum in g. Ilyper-Chem uses Gaussian Type Orbital (GTO) for ah initio methods. In truly reflecting a atomic orbital. STO may he better than GTO. so HyperC hem uses several GTOs to construct a STO. The number of GTOs depends on the basis sets. For example, in the minimum STO-3G basis set IlyperGhem uses three GTOs to construct a STO. 

To solve the Kohn-Sham equations a number of different approaches and strategies have been proposed. One important way in which these can differ is in the choice of basis set for expanding the Kohn-Sham orbitals. In most (but not all) DPT programs for calculating the properties of molecular systems (rather than for solid-state materials) the Kohn-Sham orbitals are expressed as a linear combination of atomic-centred basis functions ... 

A very important difference between H2 and molecular orbital calculations is electron correlation. Election correlation is the term used to describe interactions between elections in the same molecule. In the hydrogen molecule ion, there is only one election, so there can be no election correlation. The designators given to the calculations in Table 10-1 indicate first an electron correlation method and second a basis set, for example, MP2/6-31 G(d,p) designates a Moeller-Plesset electron coiTclation extension beyond the Hartiee-Fock limit canied out with a 6-31G(d,p) basis set. 

For all ealeulations, the ehoiee of atomie orbital basis set must be made earefully, keeping in mind the sealing of the one- and two-eleetron integral evaluation step and the... 

The smallest basis sets are called minimal basis sets. The most popular minimal basis set is the STO—3G set. This notation indicates that the basis set approximates the shape of a STO orbital by using a single contraction of three GTO orbitals. One such contraction would then be used for each orbital, which is the dehnition of a minimal basis. Minimal basis sets are used for very large molecules, qualitative results, and in certain cases quantitative results. There are STO—nG basis sets for n — 2—6. Another popular minimal basis set is the MINI set described below. 

Many basis sets are just identihed by the author s surname and the number of primitive functions. Some examples of this are the Huzinaga, Dunning, and Duijneveldt basis sets. For example, D95 and D95V are basis sets created by Dunning with nine s primitives and hve p primitives. The V implies one particular contraction scheme for the valence orbitals. Another example would be a basis set listed as Duijneveldt 13s8p . 

Binkley, J.S. Pople, J.A. Hehre, W.J. Self-consistent molecular orbital methods. 21. Small split-valence basis sets for first-row elements J. Am. Chem. Soc. 102 939-947, 1980. 

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