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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Why does iron have an abnormally high ionization energy?

Along a period the ionization energy should increase because the atomic number is increasing, but there is negligible increase in shielding. However, $\mathrm{IE}_\ce{Mn} < \mathrm{IE}_\ce{Fe} > ...
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Additional example determining Marcus parameters searched

Background / theory: The electron transfer in organic materials was formalized by the Marcus theory, introducing $|H_{ab}|$ to describe the how molecules (or more generally: sites) are coupled with ...
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Effect of spontaneous transmutation of atom in crystal

What happens to a compound when one of its atoms changes via spontaneous nuclear reaction to an atom with very different bonding? For example, beryllium-7 turns into lithium-7 with a half-life of 53 ...
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Why is nitrogen dioxide brown?

Nitrogen dioxide (NO2) is a reddish brown molecule, while its dimer nitrogen tetroxide (N2O4) is colorless. Can you give a reasonably detailed explanation for this from electronic structure theory? ...
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Program to compute multipoles of water at CCSD(T)-F12 accuracy

I want to compute traceless cartesian electrostatic multipole moment tensors up to fourth order (hexadecapole), at CCSD(T)-F12 accuracy using a large basis set. I'd like to be able to choose the ...
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239 views

Going from La to Ce, why is the extra electron added into the 4f orbital?

So, I am studying electronic configuration but the elements of the series of the lanthanides confused me. The electronic configuration of $\ce{La}$ is $\mathrm{6s^2\,5d^1}$ and that of cerium is $\...
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85 views

Why does ethene not disintegrate upon excitation?

The average c=c double bond has somewhere around 614 kJ/mol of energy, if we convert it to eV, then the bond strength is roughly 6.4 eV. Additionally, Ethene absorbs light at 171 nm. However, if we ...
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101 views

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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Trends in Slater's constant

I am aware of the various Slater rules to calculate the effective nuclear charge, $Z_\mathrm{eff}$ However, how can I decide the order in which the orbitals 2s, 3s, 3d, 3p, 4d, and 4f stand when ...
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28 views

Aluminium isopropoxide electronic structure

From Wikipedia: A tetrameric structure of the crystalline material was verified by NMR spectroscopy and X-ray crystallography. The species is described by the formula $\ce{Al[(μ-O-i-Pr)2Al(O-i-Pr)2]3}...
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111 views

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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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 ...
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301 views

Relative energies of singlet and triplet states in Jablonski diagrams

In a Jablonski diagram, we have singlet and triplet excited states where spin is conserved or changed, respectively. My book says any singlet excited state is found to have higher energy than the ...
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223 views

Difference between change in energy level and hyperfine energy level?

The second is the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom. --> This ...
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218 views

Howcome orbitals become 'core-like' when electrons are removed?

It seems to me that f-orbitals for lanthanide metals are treated as 'core-like' when a certain number of electrons have been removed. Or, as Radiochemistry puts it, The 4f binding energy is so ...
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311 views

Comparing two oxidizing agents using electron configuration

Which oxidizing agent from the pair $\ce{K_2IrCl_6/K_2PtCl_6}$ is stronger? Explain your answer using their electron configurations. We write the electron configurations for $\ce{Ir/Ir^{4+}}$ and $\...
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Are bond orders always the same in isoelectronic diatomic species?

In my textbook of chemistry it is written that: In the Lewis description of covalent bond, the Bond order is given by the number of bonds between the two atoms of a molecule. ... ...
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987 views

Some abnormalities in the Periodic Table

I observe some elements like $\ce{Cr}$ and $\ce{Cu}$. Some of them have strange oxidation numbers that don't really fit the purpose of making the element as stable as possible. Just Chromium, for ...
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Are the Phosphate and Sulfate ion diagrams with double bonds an invalid picture?

Whenever you see an image of phosphate, it's always shown having 5 bonds. 3 single bonds to anionic oxygen atoms and a double bond to an extra neutral oxygen. Not only that, but they're shown being ...
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259 views

What is the correct electronic configuration of darmstadtium?

Some of the places, the electronic configuration of darmstadtium ($\ce{Ds}$) is given as $\mathrm{6d^9 7s^1}$ while at some other places, it is $\mathrm{6d^8 7s^2}$. Which among the two is correct?
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Are Slater’s rule and lanthanide contraction contradictory?

According to most textbook and the Wikipedia page of lanthanide contraction, the phenomenon is due to poor shielding of nuclear charge by 4f electrons. However, the σ value of 4f electrons to 6s is 1....
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122 views

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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61 views

The difference between bonding and unpaired single electron radicals

I was wondering as to why would two unpaired single electron radicals form a bond. So, I tried to compute the added ground state energies of two particles in two distinct, yet identical boxes, The ...
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103 views

Multiple values for the magnetic quantum number and the spin projection quantum number?

The valence electron configuration of boron is $2\mathrm{p}^1$. So, $n=2$, and $l=1$. $m_l$ ranges from $-l$ to $l$. Can I say $m_l$ (for the specified electron) may be (-1 or 0 or +1) or should I ...
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1answer
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Tungsten 4+ ion magnetism?

I just had a quiz and struggled on a particular question: Tungsten forms a $+4$ ion. It is observed to be diamagnetic. The electron configuration for this ion may not be what you would expect. ...
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How to compare magnetic moment of chromium(III) and cobalt(II) ions?

Is there any way of comparing magnetic moment of $\ce{Co^2+}$ and $\ce{Cr^3+}$ by just going through their electronic configuration? Or is it just experimental data?
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Describe the formation of the [PbCl4]2- complex ion

The $\ce{[PbCl4]^{2-}}$ complex ion is formed when $\ce{PbCl2}$ is exposed to excess $Cl^-$ ions in solution as explained here and here through the following reversible reaction: $$\ce{PbCl2(s) + 2Cl^-...
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81 views

How to calculate electric force on valence electron?

In order to understand the periodic trends more fully, I wanted to calculate the net force exerted on the electron (with the highest principal quantum number and azimuthal quantum number) of an atom. ...
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63 views

Direction of electron density in p orbitals

$\mathrm{s}$ orbitals are spherically symmetric while $\mathrm{p}$ orbitals are not. For Boron, the electronic configuration is $\mathrm{1s^2 2s^2 2p^1}$. In which p orbital does the most energetic ...
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Are there any forbidden collisional electronic transitions?

There are spectroscopy selection rules marking some radiative electronic transitions as forbidden. For example, it is stated that single electron of H atom can not move from S2 to S1, or from P2 to S2 ...
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227 views

Does this electronic configuration violate the Hund's rule of maximum multiplicity?

I know this configuration violates the AufBau principal but does it also violate Hund's rule of maximum multiplicity?
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What is the definition of a bipolaron and a dipolaron?

I wondered about the exact definition of a bipolaron? In particular, if I have an oxygen vacancy in a metal oxide and the 2 excess electrons (when forming a neutral oxygen vacancy) localise on the 2 ...
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Autoionization state

I am reading this paper: "Role of Autoionizing State in Resonant High-Order Harmonic Generation and Attosecond Pulse Production" In the paper a transition from the $\ce{In+}$ ground state to an ...
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2answers
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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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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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Why is the electronic configuration of gold written in this order?

This is an example from my chem text. Eletronic configuration for $\ce{^79Au}$: $$\ce{1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^6 5s^2 4d^10 5p^6 \color{red}{4f^14} 5d^10 \color{red}{6s^1}}$$ (...
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Reference for assignment of symmetry (term symbols) of electronic states

I am looking for a textbook and/or internet resource where I can find the reference for assignment of symmetry of electronic states systematically. For example, $$ \ce{^1\Delta^{}_{g}}, \ce{^3\Sigma^{...
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What effect does the concentration of a metal ion have on a flame test and why should small samples of the metal ion be used?

When we conduct a flame test, say we have a solution of $\ce{NaCl}$ mixed with methanol in a ceramic bowl and we light it with a match. What effect will [Na+] have on the colour we see? If we're ...
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PAW vs USPP: Pseudopotentials in commercial DFT codes

What is the difference between USPP (ultra-soft pseudopotential) and PAW (projector augmented wave) in commercial DFT codes?
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How to tell the needed doping element for semiconductors?

I was reading about a crystal that is a semiconductor, galena. I am confused on how to tell what elements are needed to dope it to make a p or n type semiconductor, as well as how to know which ...
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460 views

Are d electrons ever delocalized in metallic bonding

It has been my understanding that delocalized electrons that participate in metallic bonds come from the highest primary energy level, specifically from the s and p sublevels and that electrons in d ...
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654 views

Causes for the irregular electron configuration of the lanthanides

I know what the electron configurations of the lanthanides are, but I was asking myself, why they are so irregular. The configutation of Lanthanum is $\mathrm{5d^1\ 6s^2}$, but according to the ...
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What intrinsic property do metals have that causes their delocalisation?

So I understand that electrons in metals delocalise completely and are free to move around. But my question is, why would something like Nitrogen not delocalise, whereas say Iron or Bismuth does? What ...
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Band alignment of heterojunctions

I have seen several band bending diagrams in journals and the web. However, I am not sure as to how they align them. Some diagram appear to align the vacuum level and some align them by Fermi Level. I ...
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Line spectrum of boron

I'm having trouble with this question from a first year undergraduate chemistry paper. The question states How many lines will appear in the line spectrum of the Boron atom if the valence electron in ...
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Fermi Level of an alloy

How could one calculate the Fermi level of a copper-nickel alloy? They are both structurally face-centered cubic, however how would this structure affect the Fermi level of the individual atom or the ...
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488 views

How to find the highest and lowest oxidation state of transitional metal

My teacher taught me the formulas 'nS' and 'nS+(n-1)d' to find the highest and lowest oxidation state of transition elements. He gave the example of $\ce{Mn}$ and showed that the numbers were +2 and +...
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Is the spin of the transferred 4s electron always opposite to the spin of 3d electron in chromium?

I am studying atomic structure and found out that Chromium has an exception in electronic configuration. One electron from 4s jumps to 3d to achieve stability. let's say the spin of transferred ...
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Should Birge–Sponer plots always have a negative gradient?

I have a set of data I would like to use the Birge–Sponer extrapolation with, but the data is the wavenumbers of the bands in the vibrational-electronic spectrum of a diatomic molecule for $v' = 0, 1, ...
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Physical interpreation of coulomb and exchange integral

When trying to solve the Schrodinger equation for the electronic hamiltonian: $$H_{el} = \sum_{i=1}^{N} \bigg( - \frac{1}{2}\nabla_i^2 - \sum_A \frac{Z}{r_{i_A}} \bigg) + \sum_{i>j=1}^{N}\frac{1}{...