7 votes

To what extent can coarse-grained models retain the essential quantum mechanical characteristics of a system?

Generally, in multi-scale modelling, QM characteristics are irrelevant. Most of the processes that we study for these multi-scale modelling are thermodynamics driven. So, I will be very surprised if ...
Roshan Shrestha's user avatar
6 votes

Why is electron correlation called the "chemical glue"?

Coincidentially, I recently read Perdew's recent autobiographical article where he also mentions the concept of "chemical glue." His simple image is as follows: The exchange–correlation ...
Kristof Bal's user avatar
  • 1,151
5 votes

Is the electron-electron interaction to blame, for the added complexity of using "orbitals" for an N-electron system?

Interpreting the question For a 1-electron system, wavefunctions and orbitals are the same thing. For a 2-electron system, or any N-electron system with N>1, we can use "orbitals" to ...
I have no free time anymore's user avatar
4 votes
Accepted

Is the one-electron reduced density matrix enough in DFT?

tl;dr "Well yes, but actually no." — the Pirate Captain (paraphrased), The Pirates! In an Adventure with Scientists! The universal 2RDM functional is known (and linear!), but 2RDMs are ...
elutionary's user avatar
3 votes

Why is electron correlation called the "chemical glue"?

Normally the correlation energy is defined to be: $E_{corr}^{basis} = E_{FCI}^{basis} - E_{HF}^{basis}$ where the superscript basis denotes each calculated in a fixed basis set. The correlation energy ...
lex2763's user avatar
  • 391
3 votes
Accepted

How is the LUMO lower energy than the HOMO for triplet state restricted-open shell DFT calculation?

It would be better to use the word SOMO (Singly Occupied Molecular Orbital), not HOMO. Now assume that you have two SOMOs (or SOMO and SOMO-1 if you prefer). Here are my suggestions: The first thing ...
jxzou's user avatar
  • 806

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