I Can we consider this system as an Einstein model of a Solid?

[Ted Ali]

Hello Everyone!
I am interested in examining the case of an isolated Einstein Solid (ES) with a decreasing number of oscillators. The total amount of energy of the ES is considered fixed. Whenever an oscillator abandons our model, it "leaves behind" the amount of energy it contained, so that the total amount of energy of the ES remains constant. As a result, the multiplicity and entropy of this ES decreases.
Can this system be considered as one (1) isolated ES?
Can we say that the entropy decreases and that our ES system gets further and further away from equilibrium?
Thank you for your time and answers,
Ted.

 

[Ted Ali]

When I started this thread, I thought that the topic and answers, would be trivial! I now think it is not.
I found the following/attached article through a Google search. In the second paragraph of the Introduction we read:

"The aim of this work is to extend the model proposed by Einstein for the case of finite
number of harmonic oscillators. To this end, mathematical functions describing analogous
thermodynamic properties for finite solids such as the specific heat and the chemical potential
were deduced. Although exhibiting, for N → ∞ , the thermodynamic behavior well-known from
textbooks [6], such analogous functions have the advantage of being defined for any N, which
allows one to explore how close to the thermodynamic behavior the properties of solids with low
numbers of particles can be. In other words, the introduction of analogous thermodynamic
functions extends the range of applications of thermodynamic, statistical and quantum mechanics,
from macroscopic to microscopic scales."

However my main question remains quite the same: What happens to the oscillators that abandon/enter the solid as N decreases/increases? Where do they go/come from? Should we consider an interaction between two (2) ES systems?