What is the wave function for the whole system/atom?

[Quandemonitum]

For example let's say that psi(q) is the wave function of an electron(which describes/represent the electron) that is located in an atom and isolated/unentangled from the rest of the system. What is the wave function value of this psi(q) ?What is the wave function for that whole atom(with only one electron=hydrogen-like atom)? What is the wave function for the whole atom[with more than one electron=multi-electron atom(other electrons are represented by other wave functions like psi(t), psi(j), psi(v) etc.)](Entanglement is not created!) ? What is the wave function for the whole atom[with more than one electron=multi-electron atom(other electrons are represented by other wave functions like psi(t), psi(j), psi(v) etc.)](Entanglement is created!) And do we ignore the entanglement principle for calculating the wave function for a whole system that contains a particle/particles because according to the entanglement since there is an entanglement in multielectron systems we can not talk about the separate wave functions, there is only one wave function that describes the whole system ?

 

[berkeman]

Welcome to the PF.

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