Journal ArticleDOI
Mixed basis functions in molecular quantum mechanics: I. Computational methods and a preliminary study of the helium atom
G. B. Bacskay,J. W. Linnett +1 more
Reads0
Chats0
TLDR
In this article, mixed sets of functions consisting of 1s Slater orbitals and floating spherical Gaussians are proposed as expansion functions for ab initio variational type calculations for small molecules.Abstract:
Mixed sets of functions consisting of 1s Slater orbitals and floating spherical Gaussians are proposed as expansion functions for ab initio variational type calculations for small molecules. After the discussion of the basic computational methods the results of some trial calculations for the ground state of the helium atom are presented.ZusammenfassungFür ab initio Rechnungen vom Variationstyp werden im Falle kleiner Moleküle gemischte Funktionssätze, die aus 1s Slater-Orbitalen bestehen, vorgeschlagen. Nach einer Diskussion der grundlegenden Rechenmethoden werden die Resultate von einigen Proberechnungen für den Grundzustand des Heliumatoms geschildert.read more
Citations
More filters
Journal ArticleDOI
Basis sets for molecular calculations
TL;DR: A general review of basis sets used in ab initio molecular calculations is presented in this article, where both Slater-type and Gaussian-type basis functions are discussed from various view points and their relative merits are appraised.
Journal ArticleDOI
The History and Evolution of Gaussian Basis Sets
TL;DR: The history and evolution of Gaussian basis sets in molecular electronic structure calculations are reviewed in this article, from the original proposals by McWeeny and Boys to the current high-quality generally-contracted basis sets of the atomic natural orbital and correlation-consistent types.
Journal ArticleDOI
Kekulé structures and topology
TL;DR: The connection between the number of Kekule structures and molecular topology is discussed in this article, where the authors also discuss the relationship between topology and kekule topology.
Journal ArticleDOI
Optimum atomic orbitals for molecular calculations A review
F.R. Burden,R.M. Wilson +1 more
TL;DR: In this paper, the Hartree-Fock framework is used for the calculation of atomic structure and the methods of using the information gained from this work in molecular calculations, but no topic is considered in full depth and only selected examples from the literature are used to illustrate the main points.
Journal ArticleDOI
Does the spatial confinement influence the electric properties and cooperative effects of the hydrogen bonded systems? HCN chains as a case study
TL;DR: In this paper, the impact of orbital compression on the energetic and electric properties as well as cooperative effects in the hydrogen-bonded systems was investigated using the MP2 method, which demonstrated inter alia that the spatial confinement significantly influences the analyzed properties.
References
More filters
Book
Methods of Mathematical Physics
Richard Courant,David Hilbert +1 more
TL;DR: In this paper, the authors present an algebraic extension of LINEAR TRANSFORMATIONS and QUADRATIC FORMS, and apply it to EIGEN-VARIATIONS.
Journal ArticleDOI
An efficient method for finding the minimum of a function of several variables without calculating derivatives
Journal ArticleDOI
Quantum Theory of Many-Particle Systems. I. Physical Interpretations by Means of Density Matrices, Natural Spin-Orbitals, and Convergence Problems in the Method of Configurational Interaction
TL;DR: In this article, the authors define a set of generalized density matrices for the Hermitean density matrix of order $k, which is further antisymmetric in each set of these indices.
Journal ArticleDOI
On the Non‐Orthogonality Problem Connected with the Use of Atomic Wave Functions in the Theory of Molecules and Crystals
TL;DR: In this article, the authors show that the overlap integrals are of essential importance in molecules and in crystals, instead of being negligible, and the problem is simply solved by considering the orthonormalized functions [open phi]μ, given by (21), as the real atomic orbitals.
Journal ArticleDOI
Atomic Shielding Constants
TL;DR: In this article, simple rules are set up giving approximate analytic atomic wave functions for all the atoms, in any stage of ionization, in analogy with the method of Zener for the atoms from Li to F, and these are applied to x-ray levels, sizes of atoms and ions, diamagnetic susceptibility, etc.