An orbital is a theoretical stable standing waveform shape in which one or two electrons can be found orbiting the nucleus of an atom.

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How does H's ionization energy relate to its transition energy (Bohr's Model)?

I am currently reviewing some material about orbital energy levels. In my review book there is a short snipet that reads: "The IE of H from its ground state (n=1) is 1312 kj/mol. Because of the ...
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Molecular orbital theory and the conservation of molecular orbitals

I am not clear with the molecular orbital theory. I have read: If the atomic orbitals are combined with the same phase they interfere constructively and a bonding orbital is formed. If the ...
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Geometry optimization near conical intersection

I have to optimize geometry in S3 state. After running optimization in MOLCAS, it couldn't converge. That was because S3 intersects with S2. I ploted energies during optimization and picked the lowest....
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Paracetamol: does oxygen participate in the delocalization of p-orbitals

I'm analyzing the molecular structure of paracetamol and one of the things I have to do is to make a commentary about the delocalization of p-orbitals in this compound. Well I know that in the cyclic ...
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Can the regions of 1s and 2s subshells overlap?

I was studying atomic orbitals and always had this question lingering. As we can see in the image, the 1s and 2s subshells both are known to closely surround nucleus. The overlapping peaks in the ...
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54 views

Energy level of hybrid orbitals in the molecular orbital energy diagram

I would like to know what is the level of energy of a hybrid orbital? For instance, lets consider the $\ce{N2}$ molecule. According to its geometry, we know that there is an orbital 2p and 2s that ...
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What's up with this quarter / three-quarter rule?

A 'quarter / three-quarter rule' is mentioned when discussing the stability of f-orbitals. What the clock does this mean? I haven't ever encountered it before, and the explanation at the above link ...
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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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Penetration effect of orbitals, ionization energy and orbital radius

So I'm a bit confused with some things I read about orbitals, ionization energy and orbital radius. So orbitals s have a stronger penetration effect compared to orbitals p and orbitals p have a ...
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Request for a graph of the combined probability density of the three p-orbitals

This started when i was wondering why p-orbitals have an unsymmetrical shape (which isn't clear to me yet). But then i came across Halliday/Resnick/Walker's Fundamentals of Physics. In it, they have ...
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81 views

Pi-acceptor Ligands

Which of the following are pi acceptor ligands? $\ce{PR3}$ $\ce{Cl-}$ $\ce{NH3}$ $\ce{H-}$ I know that $\ce{PR3}$ is a pi-acceptor, and that $\ce{Cl-}$ is a pi-donor ligand from my lectures. I am ...
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37 views

Orbital radius: is 3d less than 3s?

So I was studying some graphics of the representation of orbitals in terms of radial dependence. My graphic is similar to this one: https://www.google.pt/search?q=radial+dependence+of+orbitals&...
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Sign of the electron's wave function [duplicate]

What do the + and - sign of 2 lobes of the p orbital represent? I know that they are the signs of the electron's wave function but what is their significance?
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How do i make an molecular orbital diagram step by step?

My professor explained me, but i'm still unable to do a correct molecular orbital, for a diatomic molecule
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How to rationalise with MO theory that CO is a two-electron donor through carbon?

A question I am looking at is as follows: $\ce{CO}$ is isoelectronic with $\ce{N2}$. Sketch MO diagrams for $\ce{CO}$ and $\ce{N2}$. Point out key differences between the diagrams and use the ...
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Hybrid orbitals in molecular orbitals

In our textbook there are two topics that I can't make connection between: hybrid orbitals which (as I understand) are used to demonstrate the spacial shape of molecules like CH4 with VSEPR while ...
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table of expanded electronic structures of atoms

Where can I find the table containing expanded electronic configurations for atoms in periodic table, showing how outer electrons are distributed between different atomic orbitals? Well, i need just ...
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Relationship between ionization energy and orbitals

My chemistry book says that the ionization energy depends on the orbital an electron is taken from? I'm not sure I understand what it means. Could someone please explain this?
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What is the difference between a positive and negative electron orbital?

Why are do some electron orbitals have a negative number in the subscript (i.e. f-1), some a positive (f1), and some have a 0 (f0)? What do these numbers tell you about the atom? I know that these ...
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Are electron orbitals in a helium atom degenerate?

In a hydrogen atom, the presence of only one electron allows various orbitals' energy states to be dependent only on the principal quantum number and not on angular momentum. Orbital degeneracy and ...
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Why is there only one nodal plane in σ* molecular orbitals for homodiatomic molecules?

I know that there's one nodal plane exactly inbetween the σ* MO however why is there not three nodal planes in total? As the picture shows three areas of zero electron density (one on each P orbital ...
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39 views

Can ionic and covalent bond be explained in terms of orbitals?

Covalent bonding is stated as overlap of atomic orbitals .In ionic bonding the composite ions are held together by their electrostatic charges that result from the transfer of electrons from one atom ...
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Why are metals conductive in terms of orbitals?

Back in high school I was taught a definition of metals: Metals are a lattice of positive nuclei embedded within a sea of delocalised electrons Metals are conductive because the electrons aren't ...
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Can we find 100% probability region in an orbital if the position of an electron is limited by speed of light?

The square of the wavefunction gives probability density of finding an electron somewhere in the orbital. The text I'm referring to says that the value of probability density is always higher than ...
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2 electrons with the same spin in the same orbital

When two electrons are in the same orbital and they have the same spin do we say that the electronic configuration is impossible or that it refers to an excited state?
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Why p,d and f orbitals have non spherical shapes [duplicate]

I know what orbitals are. The orbitals are solutions (also called wave functions) to the (time-independent) Schrödinger equation[ref]. What I don't understand is why p,d,f orbitals have non ...
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What are the height and width of the large and small nodes of the sp3 hybridized orbitals of carbon and silicon?

I will make an effort to interpret answers based on wave functions, but I am a senior pursuing a bachelor's degree in Biology, so I don't have the background in quantum physics for a purely ...
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Photoionisation microscopy of hydrogen - where are the p orbitals?

In this Physics Review Letters article, which was published in 2013, but I found recently, the authors report photoionisation microscopy images of hydrogen atoms in various electronic states. A. ...
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Are empty orbitals degenerate?

This is apparently a true statement: "In a hydrogen atom, the 2s and 2p subshells have the same energy." Why is this the case? Why would they be of the same energy? Wouldn't the 2p be slightly ...
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Why can't lone pairs remain in unhybridised orbitals?

I have seen that lone pairs are almost invariably counted for determining the hybridisation of an atom. My question is why can't they remain in unhybridised orbitals.
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Are highest energy electrons lost first?

In the ground-state, is it always the case that the orbitals with the highest energy donate the electrons when the atom is ionized?
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Why does increasing orbital energy mean an electron can be more easily lost?

Why is the higher the orbital energy, the easier the electron lost? Also, if the distance between the electron and nucleus is getting father,the electronegativity is getting weaker, the electron is ...
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51 views

Question about energy of orbitals under a crystal field

It is shown in octahedral crystal field splitting that both the $e_g$ orbitals have equal energy. But how can that be possible ? The $d_{x^2-y^2}$ is directed along both the axes (x and y) whereas ...
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Electron configuration of Excited States of Fe

The electron configuration of the ground state of $\ce{Fe}$ is $\mathrm{1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^6}$. What are the configurations of its first and third excited states? The first excited ...
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What is the correct order of subshell energies? [duplicate]

I was taught in high school that the order is given by the Aufbau Principle: 1s>2s>2p>3s>3p>4s>3d>4p>5s>4d>5p>6s>4f>5d>6p... Why is the 3d subshell higher in energy than the 4s subshell if it is in a ...
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Why do atoms bond? Why are unfilled valence shells energetically unstable? [closed]

I teach school Physics. And am trying to get a reasonable explanation of the root cause of the energetic instability of unfilled outermost electron shells that leads to atoms bonding. For most of what ...
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How are the hydrogens attached to the nitrogen atom in the ammonium ion?

Naively attaching hydrogens to a nitrogen atom's electron orbitals results in a picture like this: However, there are two problems with this drawing that I can see. First, I have heard that the ...
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What kind of bonds can form between benzene and transition metals in π-complexes?

I'm trying to draw the six π-orbitals (3 bonding, which are filled, and 3 anti-bonding) of a benzene ring when it complexes with metal d-orbitals and which metal orbitals have the correct symmetry ($\...
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Negative LUMO Energy

During the (DFT-)computations that I have done over the last years, it happened quite often that I got negative energies for the LUMO and many times also for a bunch of virtual orbitals. Is there a ...
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How can the size of atom be the cause of octet expansion?

Lately, I was reading The Lewis Theory of Covalent Bonding by Peter Atkins in Appendix 4 of 'Elements of Physical Chemistry'. There he was talking about expansion of octet . As he wrote: Many ...
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How does CASSCF yield a more-negative total energy from less-negative orbital energies?

When comparing single-configurational Hartree-Fock computations with corresponding CASSCF results, it appears that the CASSCF calculation is somehow able to generate more-negative total energies from ...
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Why do octahedral metal ligand complexes have greater splitting than tetrahedral complexes?

Octahedral complexes have greater splitting in the d orbitals. Is it because octahedral complexes have more atoms and thus more interactions?
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Do orbital models derive from the solution of the stationary Schrödinger equation?

I know that hydrogen-like atomic orbitals can be seen as a solution of the stationary Schrödinger equation - but what about atoms with more electrons? As I am a pupil and quite uneducated about this ...
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Do really the electrons could only orbit in specific orbits with a fixed radius?

According to Bohr's model of atom The electrons could only orbit the nucleus in specific orbits or shells with a fixed radius. Only shells with a radius given by the equation below would be ...
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Non-mathematical explanation for why the 3d orbital generally has higher energy than the 3p orbital [duplicate]

Why does the angular momentum of orbitals(l) affect the orbital's energy? Please provide a qualitative answer.
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Lower an electron energy level by pressure [closed]

When an atom is in extreme pressure like a little before it's Schwartzchilds radius, can the electrons in higher energy levels physically be compressed into lower energy levels?.
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147 views

How to convert from spin orbitals to spatial orbitals in the Hartree-Fock approximation?

I need to calculate some of the more complicated self-energy terms from chapter 7 of Szabo and Ostlund's "Modern Quantum Chemistry", and I'm having trouble converting summations from spin orbitals to ...
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Existence of orbitals

Do orbitals exist even when they are not occupied? For example: $\ce{Cr^{+3}}$ has the configuration $\ce{[Ar]}\mathrm{3d^3}$ with the other two $\mathrm{3d}$ orbitals empty. We know the other two ...
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How to illustrate the bonding in PCl4(+) and CO2 by drawing the atomic orbitals?

Illustrating the bonding in the following molecules by drawing how the atomic orbitals are used to form the compounds A. $\ce{PCl_4^+}$ B. $\ce{CO_2}$ I believe the question is prompting to ...
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Computing two-electron integrals with an STO-3G basis set

I am trying to implement a restricted Hartree-Fock calculation using an STO-3G basis set, for fun. I managed to perform this calculation where only $\mathrm{1s}$ orbitals are present ($\ce{H2}$ and $\...