Related papers: From quantum alchemy to Hammett's equation: Covale…
We study alchemical atomic energy partitioning as a method to estimate atomisation energies from atomic contributions which are defined in physically rigorous and general ways through use of the uniform electron gas as a joint reference. We…
A new approach to chemical bonding is introduced in order to provide an improved understanding of the connection between basic quantum mechanics and the covalent pair bond. It's focus is on the fact that the energy of the bond is largely…
We assess the predictive accuracy of perturbation theory based estimates of changes in covalent bonding due to linear alchemical interpolations among molecules. We have investigated $\sigma$ bonding to hydrogen, as well as $\sigma$ and…
Accurate quantum mechanics based predictions of property trends are so important for materials design and discovery that even inexpensive approximate methods are valuable. We use the Alchemical Integral Transform (AIT) to study…
The way atoms attach to each other defines the function(s), e.g., mechanical, optical, electronic, of a given material. The nature of the chemical bond is, therefore, one of the most fundamental issues in materials. Both ionic interactions,…
We introduce "bond-counting" potentials, which provide an elementary description of covalent bonding. These simplistic potentials are intended for studies of the mechanisms behind a variety of phase transitions in elemental melts, including…
In this paper, we use density functional theory to calculate the electronic structure and properties of 46 metallic and semi-metallic elements. The binding energy and bond charge model (BBC) model is combined with the tight binding and…
We present an Atom-Pair Bond (APB) theory for the energy of a metallic bond based on the ideas of covalent bonding proposed by Pauling. An expression is derived which accurately predicts the signs of the heats of formation of binary alloys.…
The analysis of correlation energy of the simplest first approximation of a variational method for the intrashell states of two-electron atoms is the purpose of the present work. This method allows to divide energy of atom on Coulomb and…
We show in this note how many electron irreducible representations of the Lorentz group L can be expressed in terms of the sums of Slater determinants and principal minors. In this way the full configuration wave function of quantum…
In this Chapter we reexamine the concept of $\textit{covalency}$ and $\textit{ionicity}$ on example of the simplest molecules. First, starting from the exact expression for the two-particle wave function in the case of $H_2$ molecule within…
The contributions of the covalent bond energies of various atom pairs to the cohesive energy of MgB2 and AlB2 are analysed with a variant of our recently developed energy-partitioning scheme for the density-functional total energy. The…
Pauling had proposed that charge is transferred from the more electronegative atom to the less electronegative one during metallic alloying. An expression has recently been derived for the energy of the unlike atom-pair bond using that…
A simple expression for a ground state energy for a two-electron atom is derived. For this, assumption based upon the Niels Bohr ''old'' quantum mechanics idea about electron correlation in a two-electron atom is exploited. Results are…
We present a parameterized analytical model of alchemical molecular binding. The model describes accurately the free energy profiles of linear single-decoupling alchemical binding free energy calculations. The parameters of the model, which…
We develop a model of molecular binding based on the Bohr-Sommerfeld description of atoms together with a constraint taken from conventional quantum mechanics. The model can describe the binding energy curves of H2, H3 and other molecules…
Electron-electron correlation forms the basis of difficulties encountered in many-body problems. Accurate treatment of the correlation problem is likely to unravel some nice physical properties of matter embedded in this correlation. In an…
The accurate calculation of the (differential) correlation energy is central to the quantum chemical description of bond-formation and bond-dissociation processes. In order to estimate the quality of single- and multi-reference approaches…
The correlation energies of various atoms in their excited-states are estimated by modelling the Coulomb hole following the previous work by Chakravorty and Clementi. The parameter in the model is fixed by making the corresponding Coulomb…
The Resonating Valence Bond theory of the chemical bond was introduced soon after the discovery of quantum mechanics and has contributed to explain the role of electron correlation within a particularly simple and intuitive approach where…