If you pass parallel light.
This notation is so confusing! People often don't manage to explain the intuition behind it, why this is an useful notation. When you see Indian university entry exam level memorization classes about this, it makes you want to cry.
The key reason why term symbols matter are Hund's rules, which allow us to predict with some accuracy which electron configurations of those states has more energy than the other.
web.chem.ucsb.edu/~devries/chem218/Term%20symbols.pdf puts it well: electron configuration notation is not specific enough, as each such notation e.g. 1s2 2s2 2p2 contains several options of spins and z angular momentum. And those affect energy.
This is why those symbols are often used when talking about energy differences: they specify more precisely which levels you are talking about.
Basically, each term symbol appears to represent a group of possible electron configurations with a given quantum angular momentum.
We first fix the energy level by saying at which orbital each electron can be (hyperfine structure is ignored). It doesn't even have to be the ground state: we can make some electrons excited at will.
The best thing to learn this is likely to draw out all the possible configurations explicitly, and then understand what is the term symbol for each possible configuration, see e.g. term symbols for carbon ground state.
It also confusing how uppercase letters S, P and D are used, when they do not refer to orbitals s, p and d, but rather to states which have the same angular momentum as individual electrons in those states.
It is also very confusing how extremelly close it looks to spectroscopic notation!
The form of the term symbol is:
The can be understood directly as the degeneracy, how many configurations we have in that state.
Bibliography:
- chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Spectroscopy/Electronic_Spectroscopy/Spin-orbit_Coupling/Atomic_Term_Symbols
- chem.libretexts.org/Courses/Pacific_Union_College/Quantum_Chemistry/08%3A_Multielectron_Atoms/8.08%3A_Term_Symbols_Gives_a_Detailed_Description_of_an_Electron_Configuration The PDF origin: web.chem.ucsb.edu/~devries/chem218/Term%20symbols.pdf
- chem.libretexts.org/Bookshelves/Inorganic_Chemistry/Inorganic_Coordination_Chemistry_(Landskron)/08%3A_Coordination_Chemistry_III_-_Electronic_Spectra/8.01%3A_Quantum_Numbers_of_Multielectron_Atoms
- physics.stackexchange.com/questions/8567/how-do-electron-configuration-microstates-map-to-term-symbols How do electron configuration microstates map to term symbols?
After a translation between linear and physical address happens, it is stored on the TLB. For example, a 4 entry TLB starts in the following state:
valid linear physical
----- ------ --------
> 0 00000 00000
0 00000 00000
0 00000 00000
0 00000 00000
The
>
indicates the current entry to be replaced.And after a page linear address and after a second translation of
00003
is translated to a physical address 00005
, the TLB becomes: valid linear physical
----- ------ --------
1 00003 00005
> 0 00000 00000
0 00000 00000
0 00000 00000
00007
to 00009
it becomes: valid linear physical
----- ------ --------
1 00003 00005
1 00007 00009
> 0 00000 00000
0 00000 00000
Now if
00003
needs to be translated again, hardware first looks up the TLB and finds out its address with a single RAM access 00003 --> 00005
.Of course,
00000
is not on the TLB since no valid entry contains 00000
as a key. Average number of steps until reaching a state of a Markov chain by
Ciro Santilli 35 Updated 2025-03-28 +Created 1970-01-01
TODO how to calculate
Big goals:
- the pursuit of AGI
- physics simulations, including scientific visualization software
- formalization of mathematics
For some reason, this is one of the things that makes Ciro Santilli want to puke the most. More than surgery or blood.
A directed weighted graph where the sum of weights of all outgoing edges equals 1.
Sequence and organization of the human mitochondrial genome by Sanger et al. (1981) by
Ciro Santilli 35 Updated 2025-03-28 +Created 1970-01-01
As mentioned by Craig Venter in 100 Greatest Discoveries by the Discovery Channel (2004-2005), the main outcomes of the project were:
- it established the ballpark number of human genes
- showed that human genomes are very similar across individuals.
Important predecessors:
There are unlisted articles, also show them or only show them.