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Basis sets in molecular calculations

Dunning Jr., T.H. Peterson, K.A. Woon, D.E. Correlation consistent basis sets for molecular calculations , in Encyclopedia of Computational Chemistry, ed. P. von Ragu6 Schleyer, (Wiley Sons, Chichester, 1998), pp. 88-115. [Pg.192]

The distinction between atomic orbitals and basis functions in molecular calculations has been emphasized several times now. An illustrative example of why the two should not necessarily be thought of as equivalent is offered by ammonia, NH3. The inversion barrier for interconversion between equivalent pyramidal minima in ammonia has been measured to be 5.8 kcal mol However, a HF calculation with the equivalent of an infinite, atom-centered basis set of s and p functions predicts the planar geometry of ammonia to be a minimum-energy structure ... [Pg.173]

Sigeru Huzinaga, one of the pioneers in the development of Gaussian basis sets for molecular calculations, held the position of associate professor in physics at Kyushu University in the 1960s. During that time he was invited by R. S. Mulliken to join the research group at the Laboratory of Molecular Structure and Spectra at the Department of Physics of the University of Chicago, where, under Mulliken and C. C. J. Roothaan, he participated in the inception of computational quantum chemistry (1959-1961). He was appointed professor of chemistry at the University of Alberta in 1968. [Pg.242]

S. Huzinaga, J. Andzelm, M. Klobutowski, E. Radzio-Andzelm, Y. Saka and H. Tatewaki, in Gaussian Basis Sets for Molecular Calculations (Ed. S. Huzinaga), Elsevier, Amsterdam, 1984. [Pg.150]

The use of different types of basis functions in molecular calculations continues. The Os or Hulthdn-type function has been used in calculations on Hs and Ha,33 and is more effective than the Is-type function. Hj-type elliptical orbitals have also been employed in variational calculations on Hi, Ha, He 4, and H.4.34 The H orbitals were also used as basis orbitals for SCF calculations. A four-function basis set with two (non-linear) variational parameters yields 99% of the Hartree-Fock energy. [Pg.85]

Dunning TH Jr, Hay PJ (1976), Gaussian Basis Sets for Molecular Calculations. In Schaefer HF III, (ed) Modem Theoretical Chemistry, vol. 3, Plenum, New York, pp 1-27... [Pg.429]

Dunning, T.H. and Hay P.J., Gaussian basis sets for molecular calculations, in Methods in Electronic Structure Theory, H.F. Schaefer III, Editor. 1977, Plenum New York. p. 1-27. [Pg.100]

Dunning TH, Jr, Hay PJ (1977) Gaussian basis sets for molecular calculations. In Schaefer III HF (ed) Modern theoretical chemistry. Methods of electronic structure theory, vol 3, Chap 1. Plenum Press, NY, pp 1-30... [Pg.520]

A method to overcome this error is to use both basis sets in the calculation of the energy of each atom on its own so that the phantom component of the atomic energies can be determined and subtracted in what is known as the counterpoise method. BSSE can lead to over-estimations of molecular binding energies and so to the prediction of incorrect molecular geometries and charge density distributions. [Pg.195]

P. J. Hay, J. Chem. Phys., 66, 4377 (1977). Gaussian Basis Sets for Molecular Calculations. The Representation of 3d Orbitals in Transition Metal Atoms. [Pg.42]

LG. Kaplan, Symmetry of Many-Electron Systems, translated by J. Gerratt, Academic Press, New York London 1975 (p. 269, the term algebraic approximation is employed to describe the use of finite analytic basis sets in molecular electronic structure calculations)... [Pg.132]

You can use multiple basis sets in a single molecular system. The Apply Basis Set in HyperChem applies the currently selected basis set to the selected atoms or to all the atoms in HyperChem if there is no current selection. For example, some heavy atoms might have a 6-3IG basis set (s and p only) while other heavy atoms might use a 6-3IG basis set (with d-orbitals). This is an unusual but flexible option for ab initio calculations. [Pg.111]


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