Questions tagged [orbitals]

An orbital is a one-electron wavefunction, usually derived by solving the Schrodinger equation. This tag applies to questions about all forms of orbitals; additionally, questions about the construction and properties of molecular orbitals should be tagged with [molecular-orbital-theory].

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9
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2answers
2k views

In an octahedral complex, what happens to the electrons donated by the ligand?

I am trying to understand how complexes are coloured. After some reading, I found out this was due to the d-d splitting induced by the coordinate bonds of ligands to the central metal ion. The ...
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1answer
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Correlating the decrease in orbital radius and penetrating power with the increase in l value

I have read that s-orbitals have a stronger penetration effect as compared to p-orbitals and p-orbitals have a stronger penetration effect as compared to d-orbitals, etc. Therefore, the electrons in ...
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4answers
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Why is the letter J omitted in the spdf… sequence?

Under spherical symmetry, the irreducible representations corresponding to $L = 0, 1, 2, \cdots$ are assigned the letters $\mathrm{S}, \mathrm{P}, \mathrm{D}, \mathrm{F}, \cdots$ after which the ...
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1answer
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Photoisomerization of Azobenzene

Rotation around the double bond of azobenzene is restricted because it would distort the P orbital overlap between the nitrogen atoms. However, in the $n \rightarrow \pi^*$ excited state ($S_1$), the ...
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Do core electrons have molecular orbitals?

Valence electrons are associated with molecular orbitals and hybridizations. Do core electrons have molecular/hybridized orbitals, or the original atomic orbitals?
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Reason for the stronger acidic property of phenol than alcohol

In phenol, pulling the $\mathrm{p}_z$ electrons from the oxygen atom into the ring causes the hydrogen atom to be more partially positive than it is in aliphatic alcohols. This means it is much more ...
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3answers
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Why is one lobe of an sp3 hybridized orbital smaller than its other half?

A hybrid sp3 orbital is drawn with one lobe smaller than its other half, the latter which is of equal size when drawing the p orbital. Why is it so?
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1answer
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Why do tetrahedral complexes have approximately 4/9 the field split of octahedral complexes?

I am trying to calculate the relationship between the octahedral field splitting parameter ($\Delta_\mathrm{o}$) and the square planar field splitting parameter ($\Delta_\mathrm{sp}$) and thought a ...
4
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1answer
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What is the exact definition of the radial distribution function?

I have been very confused by the radial distribution function which is often used in chemistry to predict the probability of finding an electron at a distance from the nucleus. From Atkins' Physical ...
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2answers
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Quantum mechanical model of atom and the quantum numbers

I studied Bohr's model of atom and then the drawbacks of it and then quantum mechanical model of atom. Now quantum model is according to uncertainty principal and dual nature of matter and it says we ...
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1answer
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Triple Bond Character in Acyl Chlorides

I am told that because of the poor overlap between a chlorine atom and a carbon atom and chlorine's relatively high electronegativity, there is a strong partial positive character on the central ...
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Which d orbitals can form sigma, pi, delta bonds?

If two $\mathrm d_{xy}$ orbitals approach each other on $x=y,$ $z=0$, would a σ bond be formed? I would think so. Can $\mathrm d_{z^2}$ form π bond with another $\mathrm d_{z^2}?$ (As all others can ...
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Do hybrid orbitals exist in unbonded molecules? What would they look like?

For example, the ground state of a neutral carbon atom could be notated as: $$ [\ce{He}] \underset{\ce{2s}}{[\uparrow \downarrow]} \underset{\ce{2p}}{[\uparrow \vert \uparrow \vert \; \;]} $$ I ...
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1answer
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Difference between continuously overlapping p orbitals and conjugated pi bonds

Is there any difference between the phrase "continuously overlapping p-orbitals" and "conjugated pi bonds" when referring to aromatic compounds? I've heard both used and I wasn't sure if they mean the ...
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2answers
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Energy of electrons in the same subshell

So I have this quote from wikia (it's similar to my lecture pdf file) but I don't fully understand the statement Although it is commonly stated that all the electrons in a shell have the same ...
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2answers
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Where does the 9th electron go in a N=O bond?

In the first resonating structure you can see 5 unpaired electrons and 4 shared electrons on nitrogen, then isn't this a extended octet? If it is so, then in which orbital that 9th electron is ...
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Why are the radial wavefunction and radial distribution function different?

I'm having trouble understanding the following two graphs, which are the radial wavefunction of the hydrogen 1s orbital and the corresponding radial distribution function: Specifically, why is the ...
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Energy levels in an atom

I have been thinking about energy levels of an atom. When we study line spectra of hydrogen atom we say that when electrons jumps back from a higher shell to a lower shell it emits photons of certain ...
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How is the structure of triiodide ion (I3-) possible?

I have seen the structure of triiodide ion ($\ce{I3-}$) but I cannot understand why this structure is even possible. I have seen in my textbook that $\ce{I_3^-}$ is formed by combination of $\ce{...
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1answer
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Molecular orbital diagram for nitrogen monoxide, the nitrosyl cation and the nitrosyl anion

As I understand it, all of them should have same order of energy of molecular orbitals as a model for $\ce{NO}$ should withstand ionization and adding an electron. JD Lee Pg 109 shows the same ...
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Counting Nodal Planes in cyclopropane

The energy of molecule orbitals increases with more nodal planes. W1 (in the attached picture) has no nodal plane. I'd like to know how to draw the nodal planes in cyclopropane molecule orbitals but ...
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3answers
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Precise definition of atomic orbital

In school I was taught that an atomic orbital is the 3-dimensional region in which the electron is located with a probability of 90%. However, aren't there infinitely many regions of space in which ...
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315 views

I am trying to picture how electrons move around in atomic orbitals

Are they thought to continuously pop in and out of existence at various points inside the orbital defined by probabilities or do they follow definite paths that are made fuzzy by the Heisenberg ...
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1answer
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Why is the energy of an electron always negative?

I just wrote my chemistry exam a few hours ago. However, I am still confused about the following question: Why is the energy of an electron in an orbital always negative? I wrote that from the ...
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Canonical MOs vs. Localized MOs: Do both represent reality in the same way?

In my understanding localized molecular orbitals (LMOs) are equivalent to "standard" molecular orbitals, often called canonical orbitals (CMOs—by the way, why are they called canonical?). We can ...
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1answer
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Are the canonical orbitals of Hartree-Fock also the natural orbitals?

My question stems from the comments on my answer to After a unitary transformation, is Koopmans' theorem still valid?. There was some confusion relating to differing terminology referring to different,...
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1answer
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Observability of Orbitals and Orbital Energies

This question comes from some thoughts I had after reading this question. First of all, is an orbital an observable? I know the answer to this question is no because there is no "single-orbital ...
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How do orbitals coexist with a nucleus?

Many diagrams of orbitals I've seen involve electrons moving through a center point—where the nucleus is. How can this be? Clearly they don't actually pass through the nucleus, so what does happen?
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Simple Explanation of orbitals

Imagine I was your little brother, how would you explain an orbital to him? (assuming he knows what atoms electrons and neutrons are, and the rest of the basics till that point.) I have been reading ...
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1answer
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Why a higher s character increases a carbon atom's electronegativity?

To make us understand certain phenomenon like the higher acidity of alkynes than alkanes and alkenes, our teacher told us to learn this as a general rule: Higher s character leads to a more ...
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1answer
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sp² hybridized orbital

I do not understand why and how an atom with $\ce{sp^2}$ hybridization has only one p orbital?? For example in pyridine why is the lone pair of nitrogen not counted as a pi electron.
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Why does hyperconjugation help for ring cleavage?

The question was to rationalize it the ring cleavage happens concerted or non-concerted. The papers "The Mechanism of the Thermal Decomposition of 1-Pyrazolines and Its Relationship to ...
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2answers
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Is the notion of orbitals different in theoretical chemistry?

I am just an average chemistry student that is currently exposed to theoretical chemistry. And I am seeing very puzzling things, such as 1p, 2f, 3g orbitals. In my attempt to reconcile this, I was ...
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Have there been no advances in the determination of effective nuclear charges since Clementi and Raimondi in the 60s?

Effective nuclear charge is a very important concept in chemistry, and is the basis for the qualitative explanation of many observed chemical and physical properties, including several periodic trends....
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Hierarchy of electronic wavefunctions

The previous question contained too much unnecessary information and was edited. I am wondering about the "hierarchy" of wavefunctions. If one can combine atomic orbitals (AO) into molecular orbitals ...
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3answers
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Correlation between Coulomb's law and VSEPR theory

I've always been told in chemistry lessons that lone pairs repel more due to a greater charge density than bonding pairs. And that makes sense when steric effects are involved when bond orbitals ...
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2answers
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Why are sp hybridized carbocations high energy?

You don’t see carbocations on double bonds very much, and here's a good reason: compared to sp3, there is more s character in the orbitals, so the empty orbital is held more closely to the nucleus. ...
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0answers
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What is d-orbital collapse?

When I was perusing the works of Schwarz on atomic structure, I came across the unfamiliar term of d-orbital collapse. He describes it as a variation in energetic sequence from group 1 to 3 elements ...
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1answer
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Does the delocalization of p-orbitals ensure conductivity?

For example, polyacetylene is a conjugated system, i.e. with de-localized p-orbitals, but accroding to Chiang et. al. (1977) polyacetylene is semiconducting, and becomes conductive only when doped ...
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1answer
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Electronic model with highest prediction rate

Amongst many models, including the valence bond model (VB) or the molecular orbital (MO) model, which are the ones with best predictive power? (e.g. the MO is thought to predict spectroscopic ...
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Symmetry lost in orbitals?

I've always thought that orbitals lead to a loss of symmetry, and have never been able to give myself a satisfactory answer to this. I'll explain via an example: Let's take an $\ce{N^3+}$ atom. It's ...
11
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1answer
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How to derive Pauli Exclusion Principle without assuming anti-symmetry?

So, it appears that the statement of the Pauli Exclusion Principle is equivalent to the statement that fermions are anti-symmetric. That is, if you assume that fermions are anti-symmetric, then you ...
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1answer
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What type of bonding is there among d-block metals?

Metallic bond strength in $\mathrm{d}$-block elements increases up to the middle and then decreases. Why does pairing decrease the strength of metallic bond? What does pairing have to do with metallic ...
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1answer
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Why do two atomic orbitals form two molecular orbitals? [duplicate]

According to molecular orbital theory, two atomic orbitals form two molecular orbitals analogous to waves combining constructively or destructively but how can a wave combine destructively and ...
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1answer
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Significance of phase of atomic orbitals

I am learning about orbitals and bonding and antibonding MOs. So far, I know that when you combine s orbitals, you form both bonding and antibonding MOs- bonding when the wavefunctions are added in ...
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1answer
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How do electrons travel through nodes

I understand this is a basic question, but I'm having such a hard time wrapping my head around it. I'm trying to avoid thinking about it as an actual "particle" but as a wave, but that confuses me too....
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1answer
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Theoretically, Which d orbital participates in sp3d and sp3d2?

This question is regarding the old way (inaccurate) $\ce{PCl5}$ and $\ce{SF6}$ are taught in elementary chemistry. In the crystal field splitting diagram for triagonal bypyramidal geometry, $\mathrm{...
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1answer
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Why can't the conjugate base of benzoic acid be stabilized by conjugation with the aromatic ring?

All the carbon and oxygen atoms are sp2 hybridised and can have a p orbital in the correct plane yet only conjugation of the COO- group occurs. I can't think why. I can't draw resonance structures for ...
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2answers
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What is the difference between the mean radial distance and the most probable radial distance of an orbital?

I was reading JD Lee's Concise Inorganic Chemistry and it has given some values of mean radial distance which is increasing from s to p to d orbital. I had earlier read that the most probable radial ...
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What is the usage of orbitals more complex than f orbitals?

Every high school learner, in each corner of the world, faces the lesson History of Atom during his courses, just as I did. We learned about s, p, d and f orbitals, though there were no signs of ...