Many-body Rayleigh-Schrodinger

IV. Many-Body Rayleigh-Schrodinger Perturbation Theory.108... [Pg.97]

VIII. Use of the Many-Body Rayleigh-Schrodinger Perturbation Theory for the Interaction Between Two Closed-Shell Systems... [Pg.158]

I. Hubac and P. Carsky, Phys. Rev., All, 2392 (1980). Correlation Energy of Open-Shell Systems. Application of the Many-Body Rayleigh-Schrodinger Perturbation Theory in the Restricted Roothaan-Hartree-Fock Formalism. [Pg.131]

In 1967, Brandow [69] used the Brillouin-Wigner expansion in his derivation of a multireference many-body (Rayleigh-Schrodinger) perturbation theory. In the abstract to his paper entitled Tinked-Cluster expansions for the nuclear many-body problem Brandow writes ... [Pg.75]

A key feature of the many-body perturbation theory is the use of the method of second-quantization. We therefore open this section by introducing the second quantization formalism. We then discuss the Rayleigh-Schrddinger perturbation theory in its many-body form, that is, many-body Rayleigh-Schrodinger perturbation theory. We close this section by presenting the many-body perturbation theory with an emphasis on its diagrammatic formulation. [Pg.77]

Many-body Rayleigh-Schrodinger perturbation theory... [Pg.94]

In this section, we shall follow the main features of the derivation of the time-independent many-body Rayleigh-Schrodinger perturbation theory (mb-rspt) given by Paldus and Cfzek in their well-known review, published in 1975 [29]. [Pg.98]

Rayleigh-Schrodinger many-body perturbation theory — RSPT). In this approach, the total Hamiltonian of the system is divided or partitioned into two parts a zeroth-order part, Hq (which has... [Pg.236]

The adiabatic corrections to the ground state of H2, HD, and Di we shall calculate using second-order Rayleigh-Schrodinger many-body perturbation theory (RS-... [Pg.396]

The BW form of PT is formally very simple. However, the operators in it depend on the exact energy of the state studied. This requires a self-consistency procedure and limits its application to one energy level at a time. The Rayleigh-Schrodinger (RS) PT does not have these shortcomings, and is, therefore, a more suitable basis for many-body calculations of many-electron systems than the BW form of the theory, it is applicable to a group of levels simultaneously. [Pg.20]

The application of perturbation theory to many-body interactions leads to pairwise-additive and non-pairwise-additive contributions. For example, in the case of neutral, spherically symmetric systems which are separated by distances such that the orbital overlap can be neglected, the first non-pairwise-additive term appears at third order of the Rayleigh-Schrodinger perturbation treatment and corresponds to the dispersion energy which results from the induced-dipole-induced-dipole-induced-dipole78 interaction... [Pg.276]

Another approach to the problem of computing the electron correlation energy is the M0ller54-Plesset55 (MP) perturbation theory (which is philosophically akin to the many-body perturbation theory of solid-state physics). The mechanics are the conventional Rayleigh-Schrodinger perturbation theory One introduces a generalized electronic Hamiltonian Hi, where... [Pg.166]