Interaction energy of molecules

Let us consider the B cavities of a crystal of zeolite together with the adsorbed substance. Each cavity may contain not more than m adsorbed molecules. We assume that the contribution of the interaction energy of molecules which arq in different cavities to the total energy of the system may be neglected. Denoting by n the number of cavities which contain s adsorbed molecules (5 = 0, 1,. . . , m), we can write for this model the canonical partition function, Q (i, 4)... 

F (r) also represents the value, at the first order of perturbation, of the interaction energy of molecule A with a unitary point charge (e.g. a proton). 

The surface energy can be related to the interaction energy of molecules in the bulk. To show this, let us introduce the work (or energy) of cohesion, Wc. This quantity can be defined as the work of the isothermal process required to separate a column of matter having a unit cross-sectional area... 

As well as the subjects touched upon in Sections 1—10, chemical thermo-dynamicists have many other interests. (It would be easy to justify each of these even from the severely chemical point of view outlined above, but this is left as an exercise for the reader.) Among those other interests are gas imperfections and the study of the interaction energies of molecules through statistical-mechanical formulae phase equilibria, as expressed in two-dimensional sections or projections (or three-dimensional models) of (a T, Im, B,. ..) diagrams the critical state both for pure substances... 

Let us consider briefly, following the works [1-6], how the Hamiltonian of two interacting molecules, which are far from each other, may be written to apply afterwards to the van der Waals complexes. It can be expected that for the far intermolecular distances the interaction energy of molecules is weak relative to the interaction energy within a molecule. As a result, the perturbation theory can be effectively used to describe the energy and other values of interacting molecules. So, the Hamiltonian of the molecular system becomes the sum of the Hamiltonian of the free molecules A and B [Hq = H + Hf) and the interaction Hamiltonian H ... 

The Klopm an-Salem ec nalioii partition s con tribiitions to the interaction energy of two molecules into two teams, as they approach each oth er (ec nation 21) ). 

If a solid contains micropores—pores which are no more than a few molecular diameters in width—the potential fields from neighbouring walls will overlap and the interaction energy of the solid with a gas molecule will be correspondingly enhanced. This will result in a distortion of the isotherm, especially at low relative pressures, in the direction of increased adsorption there is indeed considerable evidence that the interaction may be strong enough to bring about a complete filling of the pores at a quite low relative pressure. 

For relatively long chains, average value of interaction energies of solvent molecules surrounding the chain is independent of the chain length. One more additional component of free energy of chain formation occurs because the distance between solvent molecules is defined... 

The electrical double layer at Hg, Tl(Ga), In(Ga), and Ga/aliphatic alcohol (MeOH, EtOH) interfaces has been studied by impedance and streaming electrode methods.360,361 In both solvents the value ofis, was independent of cei (0.01 < cucio4 <0.25 M)and v. The Parsons-Zobel plots were linear, with /pz very close to unity. The differential capacity at metal nature, but at a = 0,C,-rises in the order Tl(Ga) < In(Ga) < Ga. Thus, as for other solvents,120 343 the interaction energy of MeOH and EtOH molecules with the surface increases in the given order of metals. The distance of closest approach of solvent molecules and other fundamental characteristics of Ga, In(Ga), Tl(Ga)/MeOH interfaces have been obtained by Emets etal.m... 

Molecular mechanics calculations use an empirically devised set of equations for the potential energy of molecules. These include terms for vibrational bond stretching, bond angle bending, and other interactions between atoms in a molecule. All of these are summed up as follows ... 

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