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Canonical ensemble - Wikipedia, the free encyclopedia
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Grand canonical ensemble - Wikipedia, the free encyclopedia
In statistical mechanics, a grand canonical ensemble is an imaginary collection of model systems put together to mirror the calculated probability distribution of microscopic states of a given phy...
en.wikipedia.org/wiki/Grand_canonical_ensemble |
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An ensemble is specified by fixing the list of allowed states, and the statistical weight for each state. This book relies primarily on the canonical ensemble, in which the number of particles N, system volume V, ... For the canonical ensemble, the correct statistical weight of a state j was given by Gibbs as...
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Ensemble theory offers us insight through parallel universes ... Physicists call these parallel universes ensembles. I call that a fine reason for rejoicing in the hand life deals us. Ensemble theory reminds us that those other selves would be doing not much better or worse than you and I -- in the only universe we know.
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The canonical partition function for the ideal gas is much easier to evaluate than the microcanonical partition function. Recall the expression for the canonical partition function Q(N,V,T): ... gives rise to the results E=3NkT/2 and PV=NkT just as for the microcanonical ensemble. Note also that the entropy S(N,V,T) given by...
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A canonical ensemble in statistical mechanics ... of the canonical ensemble. Specifying this dependence of Z on the energies Ei conveys the same mathematical information as specifying the form of pi above. The canonical ensemble (and its partition function) is widely used as a tool to calculate thermodynamic quantites of...
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Such density operator describes the maximum entropy ensemble distribution for a grand canonical ensemble --i.e., a collection of replica systems in thermal equilibrium with a heat reservoir whose temperature is as well as in equilibrium with respect to exchange of particles with a ``particle'' reservoir where...
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4.22 we recall that in the microcanonical ensemble only those states of system were considered for which the energy was in the interval . In the canonical ensemble all energy values are permitted, but the density of state points varies strongly, as .
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The application of the density functional formalism to the canonical ensemble is of practical interest in cases where there is a marked difference between, say, the canonical and the grand canonical ensemble (cavities or pores).
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This Demonstration plots the Wigner function corresponding to a canonical ensemble of harmonic oscillators at temperature . Even though excited states of the harmonic oscillator are oscillatory, their mutual interference at finite temperatures leads to a smooth positive Wigner function.
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