Perfect pairing operator

Fig. 6. Average relativistic effective core potential and relativistic effective core potential energy curves for two states of Bi2. HF, Hartree-Fock GVB(pp), eight-configuration perfect-pairing generalized valence bond FVCI, full-valence Cl based on the GVB(pp) wave functions FV7R, full-valence Cl plus single and double promotions to virtual MOs relative to seven-dominant configurations. (The FVCI and FV7R calculations include the REP-based spin-orbit operator.)...

In MOVB theory, the role of the lowest energy HL CW in U- and [U]-bound systems is played by the perfect pairing CW. As a result, the stereochemistry of such systems is determined by the joint operation of two effects, in exact analogy with the situation encountered in VB theory ... 

This defines the CCD perfect pairing (PP) operator (22,23). Mathematically it converts the coupled cluster equations into the uncoupled cluster equations , because the amplitude equations for the valence pairs are no longer coupled to each other. The only coupling is indirect through the orbital optimization procedure. As a result of this decoupling, we anticipate (and it is true) that the... 

The fabrication and operation of a semiconductor detector are based on the premise that one starts with a perfect crystal containing a known amount of impurities. Even if this is true at the beginning, a semiconductor detector will suffer damage after being exposed to radiation. The principal type of radiation damage is caused by the collision of an incident particle with an atom. As a result of the collision, the atom may be displaced into an interstitial position, thus creating an interstitial-vacancy pair known as the Frenkel defect. A recoiling... 

CO2 laser pyrolysis of silane in a gas flow reactor and the extraction of the resulting silicon nanoparticles into a cluster beam apparatus has been shown to offer an excellent means for the production of homogeneous films of size-separated quantum dots. Their photoluminescence varies with the size of the crystalline core. All observations are in perfect agreement with the quantum confinement model, that is, the photoluminescence is the result of the recombination of the electron-hole pair created by the absorption of a UV photon. Other mechanisms involving defects or surface states are not operative in our samples. 

Interaction with the vacuum (Fig. 3.5a). In contemporary physics theory, the perfect vacuum does not just represent nothing. The electric field of the vacuum itself fluctuates about zero and these instantaneous fluctuations influence the motion of any chaiged particle. When a strong electric field operates in a vacuum, the latter undeigoes a polarization (called vacuum polarizfition), which means a spontaneous creation of matter, and more specifically, of particle-antiparticle pairs. 

We shall see, as an example, a simple counterflow cold exchanger connecting the cold and warm ends between (B) and (D) is the nearest realistic equivalent to a Carnot cycle. The idealized constant-mass flow system in a perfect counterflow heat regenerator operating with an idealized gas is thermodynamically equivalent to the adiabatic expansion paired with the adiabatic compression in the Carnot cycle, since the following intrinsic energy transfer is fulfilled in terms of a reciprocal isobaric transformation. (See Fig. 2)... 

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