Questions tagged [spin]
Spin is a type of angular momentum which is intrinsic to atomic and sub-atomic particles. Electrons in orbitals can be either spin paired or spin unpaired which influences the magnetic properties of the species containing these orbitals.
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Can the spin orientation of electrons be switched in promotion?
I know that many atoms, such as carbon, can promote electrons from lower energy orbitals to higher energy ones. But when they do so, some of the upside down arrows representing electrons are flipped ...
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Can geometry of a molecule change when the spin-orbit coupling is taken into account? [closed]
Cross-posted on MMSE.
Is there any evidence that spin-orbit coupling (SOC) leads to significant changes in atomic structure? Using DFT, I am getting different relaxed lattice constants when I take SOC ...
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Does the triplet sigma state of a diatomic molecule experience spin-orbit coupling?
I know that states with spin S=0 in a diatomic molecule have no spin orbit coupling, independent on the value of the projection of the total electronic angular momentum.
I expect the same is true if ...
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Confusion about the number of microstates for orbitals
I am very confused about the microstates for a specific orbital.
Let's suppose I have an electronic configuration
$$
\ce{[\dots] 2p^5}
$$
Considering the symmetry of the orbitals and the "...
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Do all p orbitals really have the same energy?
If we solve the time-independent Schrödinger equation for any atom by considering only the electrostatic potential, an electron has the same probability of occupying the $p_{x}$ orbital as it does the ...
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What is the origin of the spin selection rule?
Why is the change in total spin ∆S = 0 during an absorption of a photon, in contrast to the ∆L = ±1, where the photon transfers its angular momentum?
I am aware that spin-orbit coupling breaks this, I ...
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1H-NMR: What parameters influence spin-spin coupling between protons, and why?
I'd like to better understand spin-spin coupling. What other mechanisms are there besides fermi contact interactions? How are the different mechanisms influenced by different parameters like ...
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Orientation of spin polarization in O2
Oxygen gas in ground state is spin polarized. Is the direction of its spin (significantly) correlated to the orientation of the double bond?
I googled "orientation of oxygen magnetic moment" ...
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Term Symbol for Carbon
Currently studying how to "compute" term symbols. My book gives the example of carbon. Carbon has the electron configuration $(1s)^2(2s)^2(2p)^2$. We can ignore full orbitals, so we only ...
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Spin-preserving excitations
I'm currently working on quantum chemistry with quantum machine learning and one of the operations considered for the calculation is the excitation (and desexcitation) of an electron from an orbital ...
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Fermi Contact Interactions and resultant coupling contants
I am currently learning about spin-spin coupling mechanisms and have become very confused about the mechanisms by which spin-spin coupling happens in NMR.
I understand how we can draw diagrams where ...
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Is the number of particles with opposite spin roughly equal?
I was reading about the Pauli exclusion principle and this question occured to me about the electron. It can be +1/2 or -1/2 spin. And usually atoms outside stars (where it is cool enough to attach ...
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What happens when para-water ice is suddenly melted?
Background (hydrogen)
In the case of recently liquified hydrogen (which is quite cold of course) it must be re-equilibrated before loading on to a rocket as fuel to avoid a sudden exothermic ...
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Do Electrons Really 'Spin'?
With regard to the 'Electron Spin Number', lots of websites mention that electrons don't really spin and that the electron spin number has nothing to do with any physical spinning.
However, my ...
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Electronic vibrational rotational transition of electrons -- for a transition from $\Sigma$ to $\Pi$ how are P and R branches possible?
Suppose we have a diatomic molecule in a $^1\Sigma$ state, and it transitions to an excited $^1\Pi$ state. Note that the total spin of the electrons remains unchanged ($\Delta S=0$) as we can assume ...
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Why isn't Beryllium a noble gas? [closed]
Somebody answered it before on physics StackExchange, but I couldn't follow the high-level parlance. All I could follow is that it is related to the p subshell. I cannot understand why elements form ...
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Can an electron be excited to a spin state with s ≠ 1/2?
I used to think that all nuclei have fixed intrinsic value of the nuclear spin quantum number, $I$. For example, $\ce{^1H}$ must have a nuclear spin of $\frac{1}{2}$, $\ce{^{14}N}$ must have a nuclear ...
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How can a 90 degree pulse cause precession perpendicular to the applied field in proton NMR
From my understanding, a proton's magnetic moment in an NMR experiment can undergo precession in only two discrete states: either parallel to the applied magnetic field, or antiparallel to it. ...
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How do we write spin multiplicity for Mn(2+), Mn(7+)?
Mn has atomic number = 25
Since it is an exception to electronic configuration , unlike having = $\mathrm{3d^7}$ , it has electronic configuration = $\mathrm{3d^5,4s^2}$.
Formula for spin multiplicity ...
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Why are most organic molecules diamagnetic, when most of them have non-paired nucleus spins?
I was studying some coordination chemistry and somewhere around the text it was stated that one could know the magnetic moment of a complex from its metal because since all ligands were often ...
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How can Spin-Orbit-Coupling allow interactions between states with different multiplicities?
I can understand how spin-orbit coupling generates the hyperfine structures that we see in textbooks but maybe my view that the L + S momenta interacting to generate a third J momentum is too ...
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What does "spin degeneracy" mean in this context?
I am currently studying Diode Lasers and Photonic Integrated Circuits, second edition, by Coldren, Corzine, and Masanovic. In chapter 1.2 ENERGY LEVELS AND BANDS IN SOLIDS, the authors say the ...
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Why are HOMO and LUMO energies invariant under spin-flip?
Atomic theory says singlet and triplet energies for the same orbital differ because of exchange interaction. However, molecular orbital (MO) theory describes the energy between the HOMO (highest ...
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Why is the sum of the square of the orbital coefficients 1
I'm reading up on molecular orbital theory and LCAO in Ian Fleming's "Molecular Orbitals and Organic Chemical Reactions" and I don't understand the logic here:
"When there are electrons ...
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Direction of spins in the singlet vs. triplet state
Suppose we consider the first excited state of the helium atom. We know that the first excited state of helium can exist as a triplet or singlet. The possible functions related to the spin of the two ...
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the ratio between high spin state and low spin state when they coexist
I am considering the spin state's effect on the charge carrier's lifetime, I was told that high spin and low spin state could coexist when the crystal field splitting energy and the pairing energy are ...
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How can I determine the spin of a molecule?
I was reading statistical mechanics today and came across a line
For $\ce{O2}$ and $\ce{N2},$ we get half-spin, and that is why we get $σ = 2$ in their rotational partition equation.
I didn't ...
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Transition from ground state to excited state
I don't understand how to correctly find the term symbol of an excited state. I know that the first two permitted transitions for the Ne atom are 16.8eV and 19.8eV and I want to find the electronic ...
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Spin Multiplicities of Ions
The multiplicity is fundamentally defined as $2S + 1$ where $S$ is the total spin.
From what I understand, the multiplicity corresponds with the number of unpaired/paired electrons. For example, in ...
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Are nuclear spin isomers "allotropes"?
In my book there's a question:
Does $\ce{H2}$ show allotropy ? Describe its allotropes and their applications.
Wikipedia doesn't list any allotropes of $\ce{H2}$. However, when searching on the ...
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Does an electron's spin change when being excited?
My preconception is that when you fill an empty orbital by exciting an electron (with a photon), the empty orbital should be filled by an electron with the same spin. However, I've seen examples of ...
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Effect of magnetization on oxidation (rusting) of iron
Can magenetizing a piece of iron bar slow-down (or speed-up) the oxidation (rusting) process? In other words have any influence on it ?
From what I've looked up( wikipedia, quora), it appears that the ...
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How can an electron being a wave have such property as spin?
Here's what I know about electrons.
Electrons have wave-like properties and the number of wavelengths in the $n^\text{th}$ shell is equal to $n(\lambda).$ Also, I read in my book that they have ...
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What does an electron's spin of 0.5 and minus 0.5 signify?
While teaching me magnetism, my teacher told me about the spin of an electron. He told me that the spin of .5 means that if we rotate the electron twice counter-clockwise on its axis, we would have ...
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Grasping the concept of Electronic Spin, Effective Spin and Fictitious Spin
Trying to learn alone some aspects of quantum mechanics is, sometimes, a struggle. Reading the excellent paper by Piwowarska [1] I was hoping to, finally, understand what is the origin of the so-...
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Difference between spin-orbit coupling and the Russell-Saunders Effect?
The Russell-Saunders effect is the same thing as 'spin-orbit interaction, correct?
The reason I am asking is because I was reviewing the Wikipedia page on 'spin-orbit interaction' and it does not ...
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What accounts for the high spin state of the complex Tris(acetylacetonato)iron(III)?
I understand that there's 5 d-electrons for $\ce{Fe^3+}$ ion, but why it doesn't fill up the lower energy orbitals first to form one unpaired electron, but rather, filling up all the orbitals to form ...
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Methylene "anti" Jahn-Teller effect
Yesterday a Reddit user posted a page from Morrison's Organic Chemistry in which it is said that singlet methylene is less stable than triplet methylene. Another user asked basically the same I'm ...
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Mulliken Spin Density
I would like to know if a Mulliken population analysis to calculate spin densities is in general a valid choice. I see that it is made use of, for example here1. So up to-date researches apparently ...
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What is the hybridisation of [Co(H₂O)₆]³⁺? [duplicate]
There's a lot of ambiguity in the hybridisation of $\ce{Co^3+}$ in its hexaaqua complex; is it a high spin or low spin complex? As theoretically the CFSE is less than P so it should be low spin, but ...
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What is diamagnetic in diamagnetic dilution?
I'm reading a paper where the authors study a peptide solution where each peptide may have two spin labels attached to them. They put the peptides on the surface and study them using a diamond sensor.
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Spin Operator algebra
I am trying to teach myself some QM.
In Christopher J. Cramers textbook Essentials of Computational Chemistry: theory and models, in Appendix C, he goes over Spin algebra.
I am unable to calculate ...
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T1 spin-lattice relaxation times, deviation from exponential relationship
For longitudinal relaxation, one would think that the magnetic moment obeys this simple relationship
$$M_z = M_0\left[1 - 2\exp\left(\frac{-t}{T_1}\right)\right].$$
However there is always a point ...
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Sum of spins of electrons in a wavefunction
I wanted to ask a question about spin in an electron.
We were presented earlier today with the following information:
Using my synoptic knowledge, I recall that spin up $\alpha$ had a value of $+\...
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Ground state term symbol, why is $L = |M_L|$, if L must be a maximum?
I'm trying to understand how to predict ground state term symbol of atoms.
After finding the biggest S, why the biggest L will be $L = |M_L|$, where $M_L = \sum m_l$?
I know this rule works to ...
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Only d orbital electrons for spin only magnetic moment
During my chemistry lessons and self studies, I have come upon many instances where I observed that during calculations of spin only magnetic moment of transition elements only the d orbital electrons ...
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How long would it take for a tank of same-spin hydrogen atoms to become a tank of H₂?
In the question
Is there an energy cost associated with flipping the spin of an electron?, it is shown that it is very unlikely for two hydrogen atoms to bond if their electrons have the same spin. ...
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Shortcut method to find atomic term symbols ignoring the spin orbit coupling
Is there any shortcut method by which we can find the atomic term symbols ignoring the spin-orbit coupling, i.e. ignoring the values of J.
For instance, when writing the d-d transitions for any ...
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Electron Spin, and the Stern-Gerlach Experiment
I think I understand the basics of the electron spin. However, I'm trying to figure out how to tell if, when shooting a beam of atoms (the Stern-Gerlach experiment), how to tell if an element will ...
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Maximum metal-metal distance for antiferromagnetic coupling
Imagine a transition metal complex with multiple open-shell transition metal cations. If the metals are relatively close in distance, it is possible that antiferromagnetic coupling will occur between ...
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