On pseudopotential and effective-potential SCF theory and its application to compounds of heavy elements

Abstract

An effectivepotential approach to stationary scattering theory for longrange potentials A formulation of pseudopotential and effective-potential theory is developed within the framework of the Hartree-Fock formalism. It is shown that one-electron pseudopotentials may be used for many-valenceelectron atoms and molecules. An SCF computational procedure (the NOCOR method) is described that requires a minimal amount of parameterization. Sample calculations are performed on the four halogen atoms and ten dihalogen molecules. These results indicate that the "frozen-core" approximation is quite accurate at least through the fourth row of the Periodic Table. 1 N N H=L(-~.li -Z/r;)+ ZLLr;-}.If the above separability conditions are satisfied, the total energy derived from this Hamiltonian may be separated into core and valence terms,where Ee depends only on the nuclear charge and the core orbitals, which we will assume are known functions, and

Models for molecular mechanisms in drug-receptor interactions. Serotonin and 5-hydroxyindole complexes with imidazolium cation

“…The computer program was obtained from Van Wazer's group and adapted to the IBM 370/ 168 computer of CUNY. A brief outline of the method is given here; for details see [20].…”

A non-parametrized pseudopotential scheme adapted to the Hartree-Fock-Slater model

“…The usual procedure is to represent these potentials by a model potential containing parameters which are fixed by fitting either experimental atomic term values or by reference to an atomic SCF calculation. A wide variety of forms for these potentials has been proposed [12][13][14][15][16][17][18][19][20], while often the exchange potential is lumped together with the pseudopotential since both have a non-local character [21,22]. In the HFS-SCF scheme we can in the same way as in the frozen-core method [6], entirely avoid this parametrization due to the local exchange and the numerical integration scheme.…”

“…This problem has been circumvented either by arbitrarily choosing, e.g., the lowest valence level [12,13,23], or by incorporating it in the parametrization [16,21,22,24]. By applying perturbation theory, we are able to essentially solve this problem.…”

“…Finally, in calculating the valence potentials one should strictly use the coreorthogonal valence orhitals. However, most authors assume, often tacitly, that one can use the pseudo orbitals instead [12,13,16,[22][23][24]. We use a less severe approximation in which we assume that the difference between pseudo and valence density is constant from system to system.…”

Catheter treatment of critical aortic valve stenosis in the neonate: Choice of approach

“…Our task is the classic task of the theory of pseudopotentials (a subsystem in the field of frozen remaining part of the whole system). This theory 18–21 is well developed for molecules for the case of valence electrons in the field of core electrons. In this case, nonorthogonality of valence pseudowave functions to the core wave functions only appears to be significant.…”