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Molecular symmetry in Ab initio calculations
Journal of Computational Physics, 1987A scheme is presented for the construction of the Fock matrix in LCAO-SCF calculations and for the transformation of basis integrals to LCAO-MO integrals that can utilize several symmetry unique lists of integrals corresponding to different symmetric groups.
Madhavan, P. V., Whitten, J. L.
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AB Initio Calculations on Sulfonylmethyl Anions
Phosphorus, Sulfur, and Silicon and the Related Elements, 1994Abstract The role of negative hyperconjugation in the title compounds is elucidated by the results of quantum chemical ab initio calculations.
Gerhard Raabe +2 more
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Emission Spectroscopy and Ab Initio Calculations for TaN
Journal of Molecular Spectroscopy, 1999The emission spectrum of IrN was recorded in the near infrared using a Fourier transform spectrometer. The IrN molecules were excited in an Ir hollow cathode lamp operated with a mixture of Ne and a trace of N(2). Numerous IrN bands observed in the 7500-9200 cm(-1) region were assigned to a new a(3)Pi-X(1)Sigma(+) electronic transition with the 0-0 ...
Ram, Ram +2 more
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Acetone, ab initio calculations
Tetrahedron, 1972Abstract Ab initio calculations on acetone using a 5,2,2 (contracted to 3,1,1:1 for carbon and oxygen, and 1 for hydrogen) Gaussian basis set gives a molecular energy of - 190·68162 Hartrees. The methyls have hydrogen eclipsing oxygen in the ground state. The rotational barrier is 0·99 kcal/mole.
N.L. Allinger, null M.J. Hickey
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Ab initio calculations of biomolecules
AIP Conference Proceedings, 1995Ab initio quantum mechanical calculations are valuable tools for interpretation and elucidation of elemental processes in biochemical systems. With the ab initio approach one can calculate data that sometimes are difficult to obtain by experimental techniques. The most popular computational theoretical methods include the Hartree‐Fock method as well as
Andrzej Leś, Ludwik Adamowicz
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Boron in ab initio calculations
Computational Materials Science, 1998Abstract Based on ab initio quantum chemical Hartee–Fock (HF) approximations, density functional theory (DFT) and LMTO-ASA methods, we have determined the geometric and electronic structures of atomic-scaled boron clusters, surfaces and nanotubes. The starting structures were constructed with the help of an `Aufbau principle', previously proposed for
Ihsan Boustani, Alexander Quandt
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2010
Ab initio calculations rest on solving the Schrodinger equation; the nature of the necessary approximations determines the level of the calculation. In the simplest approach, the Hartree-Fock method, the total molecular wavefunction Ψ is approximated as a Slater determinant composed of occupied spin orbitals.
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Ab initio calculations rest on solving the Schrodinger equation; the nature of the necessary approximations determines the level of the calculation. In the simplest approach, the Hartree-Fock method, the total molecular wavefunction Ψ is approximated as a Slater determinant composed of occupied spin orbitals.
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1998
Various difficulties of classical physics, including inadequate description of atoms and molecules, led to new ways of visualizing physical realities, ways which are embodied in the methods of quantum mechanics. Quantum mechanics is based on the description of particle motion by a wave function, satisfying the Schrodinger equation, which in its “time ...
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Various difficulties of classical physics, including inadequate description of atoms and molecules, led to new ways of visualizing physical realities, ways which are embodied in the methods of quantum mechanics. Quantum mechanics is based on the description of particle motion by a wave function, satisfying the Schrodinger equation, which in its “time ...
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Ab Initio Calculations of Fullerenes
Science, 1996Recent advances in ab initio electronic structure methods have brought about a substantial improvement in the capabilities of quantum chemists to predict and study the properties of clusters. The carbon cages known as fullerenes have been the focus of much attention because of their remarkable properties. This article discusses the application of state-
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