Polarization of atoms

Recalled in Arthur Lapworth, "Latent Polarities of Atoms and Mechanism of Reaction, with Special Reference to Carbonyl Compounds," Mem.Manchester LPS 64, no. 3 (191920) 15. 

Arthur Lapworth. "Latent Polarities of Atoms," 116 Robert Robinson, "The Conjugation of Partial Valencies," ibid., no. 4 (1920) 114. This paper is reproduced in Robinson s Memoirs. 

W. O. Kermack and Robert Robinson, "An Explanation of the Property of Induced Polarity of Atoms and an Interpretation of the Theory of Partial Valencies on an Electronic Basis, JCS 121 (1922) 427ff quoted in Seddon, "Development of Electronic Theory," 25. W. O. Kermack was a member of the Royal College of Medicine at Edinburgh. 

It is true that all molecular and atomic forces ultimately find their root in the mutual behavior of the constituent parts of the atoms, viz., the nuclei and the electrons. They may theoretically all be derived from the fundamental wave equations. It is, however, convenient, as in other branches of physics and chemistry, to treat the various forms of mutual interaction of atoms as different forces, acting independently. We shall therefore follow the usual procedure and treat such forces as the nonpolar van der Waals (dispersion) forces, the forces of the electrostatic polarization of atoms or molecules by ions or by dipoles, the mutual attraction or repulsion Coulomb forces of ions and of dipoles, the exchange forces leading to covalent bonds, the repulsion forces due to interpenetration of electronic clouds, together with the Pauli principle, etc., all as different, independently acting forces. 

Rothe, E.W., Krause, U. and Duren, R. (1980). Observation of polarization of atomic fluorescence excited by laser-induced dissociation of Na2, Chem. Phys. Lett., 72, 100-103. 

To improve upon a double- basis, one generally adds polarization functions whose / values correspond to orbitals unoccupied in the free atoms. For example, to expand upon a double- basis for HjO, one would add 2p functions on H and 3d functions on O. Such functions are called polarization functions since they describe the polarization of atomic electron density arising from molecule formation. For example, if a H atom is placed in the electrostatic field of an O atom, its electron density will be polarized along the 0-H bond direction, a change that can be described by the mixing of H 2p character into the His wave function. 

ALTERNATING POLARITY OF ATOMS IN VALENCE BOND STRUCTURES... 

Polarization of atoms The separation of charges in response to some stimulus. 

C QM/MM methods of type C extend beyond type B by also including some polarization of atoms in the MM region by the electric field generated by the QM region. 

Covalent and van der Waals radii are other fundamental properties of atoms in molecules that are influenced by nuclear charge and electron distribution. A glance at a molecular model or graphic suggests that most atoms have several different dimensions. There is the distance between each bound atom and also a dimension in any direction in which the atom in not bonded to another atom. The former distance, divided between the two bonded atoms, is called the covalent radius. The nonbonded dimension of an atom or group in a molecule is called the van der Waals radius. This is the distance at which nonbonded atoms begin to experience mutual repulsion. Just short of this distance, the interatomic forces are weakly attractive and are referred to as dispersion or London forces and are attributed to mutual polarization of atoms. 

The Vibrational Excitation of Molecules by Electron Impact, D, G. Thompson Vibrational and Rotational Excitation in Molecular Collisions, Manfred Faubel Spin Polarization of Atomic and Molecular Photoelectrons, N. A. Cherepkov... 

In Fig. 31.2, the structure of the Mg subsystem of the H-ras GTP complex is shown. We optimized the position of the hydrogen atoms so that the position gives the minimum energy of the Mg subsystem. In this process, we use the Merz-Kollman charges [20] as the atomic charges in order to treat the polarization of atoms in the Mg subsystem efficiently. 

The biggest number of spherical atoms of the same diameter, capable of touching only one atom of the same diameter was 12. From this there followed that A+12B contains the bigger number of atoms which can be contained in an composed atom of first kind. If, on the other hand, we are paying attention to the electric polarity of atoms, an atom A cannot combine with more than 9B atoms if the atom A+9B conserves any part of the original electrical polarity of A. For example, the oximuriatic acid which was a compound of an atom of muriatic... 

Kermach WO, Robinson R (1922) Explanation of the property of induced polarity of atoms and an interpretation of the theory of partial valency on an electronic basis. J Chem Soc Trans 121 427 0... 

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