Selection of configuration

Busses are typically made of aluminum or copper and are rigid bars in the substation, insulated from gi ound and other equipment through ample insulating material, typically air or sulfurhexafluoride. The arrangement of the busses in the substation may fall into a number of different categories the most common are illustrated and explained in Table 1. The appropriate selection of configuration is made by carefully balancing cost, reliability, control, and space... 

The selection of configuration state functions to be included in MCSCF calculations is not a trivial task. Two approaches which can reduce the complexity of the problem are the complete active space self-consistent-field (CASSCF) [68] and the restricted active space self-consistent-field (RASSCF) [69] approach. Both are implemented in the Dalton program package [57] and are used in this study. Throughout the paper a CASSCF calculation is denoted by i active gactive RASSCF calculation by For the active spaces of HF, H2O, and CH4... 

P. Bogdanovich, R. Karpuskiene, A. Momkauskaite, A program of generation and selection of configurations for the configuration interaction method in atomic calculations SELECTCONF, Comput. Phys. Commun., 172, 133-143 (2005). 

The major problem with MCSCF methods is selecting the necessary configurations to include for the property of interest. One of the most popular approaches is the Complete Active Space Self-consistent Field (CASSCF) method (also called Full Optimized Reaction Space, FORS). Here the selection of configurations is done by partitioning the MOs into active and inactive spaces. The active MOs will typically be some of the dii rest occupied and some of the lowest unoccupied MOs from a RHF calculationr Fhe-daactive MOs either have 2 or 0 electrons, i.e. always doubly occupied or empty. Within... 

A selection of configurations, suitable for most reflux procedures is shown in... 

One way forward from this point is to carry out calculations of Q " ( e ) for a selection of configurations ( spin spirals, two impurities in a ferromagnet, magnetically ordered superceUs, etc.) by making some assumptions about the most dominant fluctuations. One then fits the set of Q " ( e ) s to a simple functional form. Typically a classical Heisenberg model, Q " ( e ) = is set up... 

Shavitt, I., The method of configuration interaction, in Methods of Electronic Structure Theory H. F. Schaefer III (Eds), Plenum, New York, 1977 p. 189. An authoritative review by a leader in the field discussing many aspects of Cl (symmetry- and spin-adapted configurations, construction and diagonalization of the Cl matrix, selection of configurations, etc.). 

Fig. 5.2 Selection of configuration methods according to the modeling scope...

The main difficulty in the selection of configurations...was of course the enormous number of possible configurations. In a typical calculation there are billions of configurations which can be formed with the correct mmetry. For an unfortunate choice...all of these might be equally important, but for a good initial guess only a few will really contribute to the wavefunction. (Bender, Davidson 1966,2676). 

Freestanding stacks of even greater length can be achieved by prudent selection of configuration, material type, thickness, and support arrangement. 

The Pauli principle must still operate for molecules and takes the form that n, /, and mi cannot be alike for two electrons unless their spins are antiparallel. However, n and / may not always be defined. Equivalent electrons become defined as those with identical A and closed shells have two electrons for A = 0 (a ) but four electrons for A 7 0. The molecular electronic configurations can then be built up and the possible spectroscopic terms derived by a vector coupling procedure. The small size of closed shells makes this a much simpler exercise than for d or P atomic configurations. Table VIII presents the terms for a selection of configurations. The order of filling orbitals is, however, complicated by the greater number of possibilities and one is restricted to applying some sort of Aufbauprinzip within sets of like molecules only. ... 

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