The design of distributed control computer systems

Gościński, Andrzej; Zieliński, Krzysztof

doi:10.1016/0166-3615(85)90068-5

Cited by 3 publications

(1 citation statement)

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“…In analogy with (4.9) and (4. lo), one gets immediately where the relations (4.12) (4.13) where the quantity R ( z ) = ( z . 1 -L)-' is the superresolvent, the importance of which has been stressed by Goscinski and his collaborators [24].…”

Section: )mentioning

confidence: 99%

Some current problems in theoretical chemical physics to be solved

Löwdin

1994

Int J of Quantum Chemistry

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Quantum Chemistry can today boast the fact that ordinary chemists-by means of personal computers and programs available-can study many theoretical properties of molecules by solving the SchrMinger equation and get an advance idea of how to properly arrange their experiments to find new features. For small molecules, they can use ab initio programs of the Hartree-Fock type, and for large molecules, they can use semiempirical programs available. To achieve higher accuracy and to include electron correlation properly, however, one has in the ab initio approach to use configurational interaction methods and giant computers, whereas in the semiempirical methods, the effect of correlating is often taken into account in the adjustable parameters forming the basis for this approach. In connection with the ab initio methods, it is further emphasized that the resolvent methods combined with the partitioning technique provide an excellent conceptual and mathematical framework for getting solutions of any accuracy desired, but that most of the programming of this approach remains to be done. Ordinary wave mechanics is valid at absolute zero of temperature, and-in order to include such important chemical concepts as temperature, entropy, free energy, etc.-one has to go over to general quantum theory and the Liouvillian formalism. One can still start from the Coulombic Hamiltonian, but it becomes of importance to include the nuclear motion properly and preferably on the same level as that of the electronic motion. It is further emphasized that the irreversibility problem is not yet fully solved, that the theory of the interaction between matter and electromagneticfields still needs some improvements, and that the question of the proper introduction of relativistic corrections in the quantum theoretical treatment of molecular systems involving heavier atoms still has a great deal to desire.

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confidence: 99%