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Questions tagged [electronic-configuration]

In atomic physics and quantum chemistry, the electron configuration is the distribution of electrons of an atom or molecule (or other physical structure) in atomic or molecular orbitals.

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How can I write electron configuration for Li2O?

I know how to write electron configuration for Lithium and Oxygen separately, but I don't how to write it as a compound Li2O. Please explain this to me. Thank you.
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How does successive ionisation energy data relate to electron configuration?

Explain how successive ionisation energy data is related to the electron configuration of an atom. Like what are the patterns or trends etc, please show me some if possible. Thankyou. <3
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How to derive a state symmetry in D2h point group from its wavefunction?

Let's have an atomic carbon with the following electron configuration: $$ 1s^2 2s^2 2p^2 $$ One of it's levels is ${}^1S_0$, which is corresponding with the following state: $$ \begin{align} \left| ...
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How to specify atomic carbon terms in the coupled and uncoupled representation?

So, we know, that the atomic carbon in the electronic configuration $1s^22s^22p^2$ has the following terms $${}^1S, {}^1D, {}^3P$$ My question is - how can I correctly specify these terms in the ...
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Aufbau principle in filling Ti

A few weeks ago, I was given this question to complete: The ground state electronic configurations of Ti is $\ce{[Ar] 4s^2 3d^2}$ State whether it follows the Aufbau principle or not. If not, ...
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What does it mean that an electron quantum numbers are n1= 4 - l1?

I'm trying to solve some exercises from the 2017 IChO, and the problem 6-A1 states that in first ionization, an electron with the quantum numbers $n_1 = 4 - l_1$ is removed. Now, I've never seen ...
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1answer
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Why is helium considered as a non-metal?

How can helium be considered as a non-metal based on its chemical properties? Helium is a noble gas; it does not take part in chemical reactions under ordinary conditions. But non-metals tend to gain ...
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Software for the atom model of all elements [closed]

I want an atom model with shells but I haven't found one yet and the only software that created an atom was Cinema 4D. This software is not for beginners like me and I used a tutorial to make an atom ...
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Density of D-block elements

Something that confuses me slightly is the trends in density when comparing periods 4, 5, and 6 in the d-block. Looking at periods 5 and 6, the density peaks at group 8, with Ruthenium and Osmium ...
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Which is more reactive, chlorine radical or chloride ion?

Ions are very reactive for obvious reasons (i.e. Coulomb force); $\ce{Cl-}$ ions will be very quick to form an ionic bond with positive ions (unless inhibited, e.g. through being in a solution; let's ...
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Why has na 1S0 term Ag symmetry?

This question is a continuation of Molpro - Connection between atomic term symbols and system symmetry. In the Feodoran's answer I found it somehow confusing, that ${}^1S_0$ term should be totally ...
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Molpro - Connection between atomic term symbols and system symmetry

Let's say I have a carbon atom with the electron configuration $1s^22s^22p^2$. We know, that using atomic term symbols we can describe the following states: $${}^3P_0, {}^3P_1, {}^3P_2, {}^1D_2, {}^...
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What is the sense of electronic configuration of an atom if an electron can be in any superposition of energy eigenfunctions?

I recently started learning abou the quantum mechanical explanation of hydrogen atom. In the derivation of the wave functions of hydrogen atom we find its energy eigenfunctions. But according to the ...
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Connection of term symbols with specific microstates for atomic carbon

I'm currently studying atomic term symbols. I wanted to try it on a simple atomic carbon with the electron configuration $1s^22s^22p^2$. I know, that only open-shell electrons are involved in the ...
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1answer
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Why is the active space for the dinitrogen cation defined this large in my example?

I have a Molpro script which computes $\ce{N2^+}$ potential energies. The significant part is the input for the wave function: ...
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How to explain the excited states in the dinitrogen cation?

The $\ce{N2^+}$ molecule has the molecular orbitals $$\ce{\sigma(1s)^2\; \sigma^*(1s)^2\; \sigma(2s)^2\; \sigma^*(2s)^2\; \pi(2p_x)^2 \; \pi(2p_y)^2 \; \sigma(2p_z)^1,}$$ which can be seen on the ...
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Bromination on aromatic compound

So guys, very quick question: Why does bromination occur at exactly this position on the aromatic ring? Has it something to do with the substituents and their respective electronic effects?
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Molpro - Simple explanation of OCC, CORE, FROZEN and CLOSED orbitals

I'm beginning with quantum chemistry and I'm supposed to do some ab initio calculations with Molpro. The problem is, I don't understand the orbital specification very well. Let's say, I have the ...
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1answer
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Can two atoms with the same amount of electrons but differing electronic configurations be considered isoelectronic?

Can two atoms with the same amount of electrons but differing electronic configurations be considered isoelectronic? For example, would we consider yttrium(I) $(\ce{Y+})$ with configuration: $\ce{[Kr]...
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What is the difference between carbon in an excited state and with sp³ hybridization?

What is the difference between the carbon in the excited state, $\ce{[(1s)^2] (2s)^1 (2p)^3}$, and $\pu{sp^3}$ hybridization?
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Find the Electronic Configuration of an Iron Atom [closed]

I'm confused. Iron has 26 electrons and I wrote down $\ce{1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 4s^2, 3d^6}$ yet my answer booklet says $\ce{1s^2, 2s^2, 2p^6, 3s^2, 3p^6}$ but that is only 18. How can it be ...
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Number of configurations/states for electrons in orbitals

I'm performing complete active space calculations for the prediction of X-ray absorption L edge spectra. This involves an excitation from 2p orbitals to the 3d orbitals of the metal. For the ...
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the pattern of losing electron [duplicate]

The question is the electron configuration of $\ce{Fe2+}$. Why does it lose the electron of $4s^2$ first instead of losing $3d^2$? I consider the pattern of the losing electrons in the $p$ orbital. ...
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1answer
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Molecular electronic state symmetry

I am trying to work out the ground state symmetry of electronic states. The paper states the GS symmetry is $^6A_1$ for the right hand side electron configuration and $^4B_1$ for the LHS in the D$_{2\...
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1answer
263 views

Is cobalt(II) in the hexaamminecobalt(II) complex high spin or low spin?

I want to determine the electronic configuration of $\ce{Co}$ in $\ce{[Co(NH3)_6]Cl2}$ with Crystal Field Theory. I know that since the complex is octahedral, there would be degeneracy breaking and ...
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Lewis structure for magnesium diboride

What is the Lewis structure for $\ce{MgB2}$? I just read that it is a superconducting material (up to a relatively high critical temperature, 39 K) and am wondering if this has to do with its ...
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0answers
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Why electron configuration of tungsten doesn't obey the full & half full (stability) rule? [duplicate]

So I was reviewing chemistry lesson and I am curious when I saw the electron configuration in the VIB group: For $\ce{_24Cr}$ we write the electron configuration $\ce{_18[Ar] 4s^1 5d^5}$ instead of $\...
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1answer
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Knowing that CI is variational for any basis set, why is coupled-cluster variational in the full correlation limit?

This is the question asked in Martin's comment to my answer to: Why is Coupled Cluster not variational? In the comment I was also asked to provide a publication as a reference:
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1answer
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Very elementary question about valence electrons of ionic compound

In a university entrance question, I found this question: What is the number of valence electrons of $\ce{Mg(OH)2}$? Answer = 24 I know that Mg has 2 valence electrons and O has 6. But I don't ...
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Bond order analysis in molpro

I'm trying to compute bond orders in a molecule, let's consider S2 as an example. I'm not entirely sure what's the right way to do that, but I assume NBO (Natural Bond Orbital) should give me what I ...
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Regularity of electron configuration for heavier atoms [closed]

Edit: Is there structure in the nucleus that might be responsible for part of the regularity of the (ground-state) Aufbau process? The periodic addition of electrons is more than one might naively ...
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Electron filling p orbital,which of them will firstly filled with two electrons and why?

According to hund's rules if degenerate orbitals are availible then electron will fill them up singly before they pair up. My question is in p orbital which(px,py,pz) orbital will be first filled with ...
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Valence shell expansion and sulfur

I've been searching some things regarding the ability of sulfur to accomodate negative charge and reached the conclusion that it's due to its size and its ability to expand its valence shell. I can't ...
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Electronic configuration of vanadium ion in a compound with magnetic moment 1.73 bm [duplicate]

Vanadium has $Z = 23$ and so the electronic configuration of an isolated neutral atom in the gas phase would be $\ce{1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^3}$. Now, magnetic moment of 1.73 means 1 ...
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Standard electronic configuration

I have never understood, or I have not been able to explain well, why some elements do not "follow" the "standard" electronic configuration, I explain myself, for example in cases like $\ce{N}$ ...
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1answer
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Why the energies of orbitals in the same subshell decrease with increase of atomic number?

Why the energies of orbitals in the same subshell decrease with increase of atomic number? For eg., energy of 2s orbital of hydrogen atom is greater than energy of 2s orbital of lithium atom. What is ...
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1answer
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What do you think is a good way to explain electronic configurations? [closed]

Understanding electronic configurations is vital, but a huge number of students face difficulties in understanding the why and the how. What approach do you think I should take in explaining ...
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Accuracy benchmarks for atomic multipole moments

Thermochemical accuracy is regularly quoted as 1 kcal mol$^{-1}$, or 4.2 kJ mol$^{-1}$. I'm expressing some data and I want to use benchmarks like this to validate them, however, they are not all in ...
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1answer
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Jahn Teller Effect for d4 low spin configurations

Why does Z-in take place in $d^{4}$ low spin configuration whereas in Z-out one can get all the 4 electrons in $d_{xz}, d_{yz}$ which would lead to lower energy
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Why is zinc not considered to have a noble gas configuration?

I am wondering why we say that, for example, zinc does not have a noble gas configuration? I would like to say beforehand that this question may has its origin in a confusion about the word "shell" ...
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Is the shorthand electron configuration of Br- just [Kr]?

Is the shorthand electron configuration of $\ce{Br-}$ just $\ce{[Kr]}$? Also what about $\ce{Ca^2+}$—is it just $\ce{[Ar]}$? And, is $\ce{Na+}$ just $\ce{[Ne]}$?
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Size consistency in computational chemisty methods

I am looking for a clear answer that would explain what exactly size consistency is, why configuration interaction (CI) is not size consistent and how this leads to errors when using CI for large ...
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2answers
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What is the number of unpaired electrons in (Fe(H2O)5NO)2+? [closed]

Given the fact that $\ce{NO+}$ is a strong field ligand and iron is in the +1 oxidation state, the valence orbitals of $\ce{Fe+}$ must undergo rearrangement from $\mathrm{3d^{6}4s^{1}}$ to $\mathrm{3d^...
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Why do tungsten and chromium have different electronic configurations? [duplicate]

Why is the outer structure of tungsten $\mathrm{5d^46s^2}$ instead of $\mathrm{5d^56s^1}$? I try to explain this in comparison with outer structure of chromium $\mathrm{4d^55s^1}$ taking into ...
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Why do halogens have odd numbers as oxidation number?

Halogens like $\ce{Cl}$ always exhibit $+7,+5,+3,+1,-1$ as their oxidation numbers. I found the following answer after checking several sources: Halogen atoms have $7$ electrons in their valence ...
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Why does cobalt have no negative charge?

I would like to know why cobalt cannot have a negative charge (or at least why a negative charge for cobalt isn't typical). I am not sure where I have gone wrong in my reasoning. The electronic ...
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535 views

Exceptional electronic configuration?

The general electronic configuration for f-block is: (n-2)$f^{0-14}$ (n-1)$d^{0-2}$ n$s^2$. Then why the configuration of Thorium is [Rn] $6d^2$ $7s^2$. It should be [Rn] $5f^1$ $6d^1$ $7s^2$ as per ...
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1answer
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Why does potassium have the electronic configuration of 2.8.8.1? [duplicate]

We all know that potassium, the 19th element on the periodic table has the electronic configuration of 2.8.8.1. However, why not 2.8.9? In the element scandium, it has the electronic configuration ...
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1answer
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D6h symmetry clusters- orbital classification confusion!

I was am simulating high symmetry clusters D6h in several programs such as molcas and gaussian. I understand that the highest symmetry used in these programs is D2h and therefore there would be mixing ...
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Identifying luminescent transitions for lanthanides

Using the ground-state of Eu(III), how can I identify the possible (number of) luminescent transitions from the $^{5}D_{0}$ excited state? I identified the ground-state term symbol for Eu(III) using ...