Quantum mechanics is the discipline of physics that focuses on physical phenomenon that occur at an atomic or sub-atomic scale. In particular quantum mechanics attempts to describe the interaction of energy and matter, which can be described using both particle-like and wave-like interactions.
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Degeneracy of orbitals?
Why is that in an external magnetic field(uniform) the degeneracy of d,f orbitals is lost but the degeneracy of p orbitals remain intact if the main cause of losing degeneracy is the difference in ...
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Quantum tunneling is faster than light travel? [closed]
Quantum tunneling is faster than light travel ?
My reasoning is that the particle cannot be detected inside the tunnel so if it travels from A to B it must be instantly going from A to B , hence ...
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Approximation of electron density of a small molecule
Starting point for Quantum Theory of Atoms in Molecules (AIM) is the electron density $\rho(r)$. It could be determined experimentally (X-ray diffractions). I want to know how can we estimate them ab ...
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Did Mendeleev predict the existence of neutrinos?
According to this Wikipedia page, Mendeleev originally believed that the inert gases belonged in Group 0 (to the left of the alkali metals). Thus, helium would be placed in the second period to the ...
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Anomalous Electron Configurations
Cu has an anomalous electron configuration. Cu = $1s^22s^22p^63s^23p^64s^13d^{10}$, it does not follow the usual pattern. In this case, the 3d subshell is filled before the 4s, which usually happens ...
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Quantum dot band gap energy equation
I have been looking into certain approximations for band gap energies in quantum dots and have found this paper (Band-structure-corrected local density approximation study of semiconductor quantum ...
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Is it possible to work out the colour of *any* molecule?
Above are some spectral emission lines for Hydrogen, Helium and Neon.
Using the Schrodinger equation, it's possible to derive the colours that Hydrogen will emit when light is fired at it. A ...
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Bonding and anti-bonding orbitals in the light of time-dependent Schrödinger equation?
In organic chemistry, people draw 2p orbitals like this:
and then they explain how the orbitals combine to non-bonding (π*) or bonding (π) molecular orbitals, like this:
depending on whether the ...
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Why are these molecular orbitals invalid for hexatriene?
Here are the MOs (more accurately, the breakdown of the MOs) for conjugated hexatriene:
Now, when first asked to draw the MOs myself, I drew this one for $\psi_3$:
It still has two nodes, and is ...
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Good introductory books on quantum chemistry [closed]
What's a good book to start learning about quantum chemistry , and how much math do i need to know?
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Why are there quantised energy levels in the vibrational energy of a molecule?
Why are the energy levels for vibrational energy in a molecule discrete as opposed to continuous?
I don't understand how a vibration can't have continuous amounts of energy that depend on the ...
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Quantum Mechanics – Spin-Orbit Coupling; Spin-Orbit Hamiltonian
When spin-orbit coupling occurs, it adds a term to the potential energy of the
Hamiltonian, which usually causes a small splitting of the energy levels, but otherwise leaves all other energy terms and ...
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A question about Pauli’s exclusion principle and electron orbital
According to Pauli’s exclusion principle, an $s$ orbital contains at most two electrons with the opposite spin (up and down). Why can't an $s$ orbital contain a third electron whose state is the ...
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Can quantum entanglement affect the chemistry of molecules?
I recently heard a talk from a physicist about experiments on simple two-atom molecules in vacuum that showed that certain behaviour of the molecules was explained by quantum entanglement. Now this ...
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Energy of the n-th level for an atom
Going through the Bohr's model and his assumptions, I came across with this formula to find the energy of the n-th level of any atom:
Now, let's say we take as an example the atom of hydrogen, the ...
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Does this set of quantum numbers have a unique solution?
I received the following question:
Complete the missing values for the four quantum numbers:
$n=?$, $\ell = 2 , m_\ell = 0$ , $m_s= ? $ .
The problem is that I think $n$ can be any number ...
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Is there a similar characteristic of the Lanthanide Contraction in the other transition metal groups?
Basically, does this also occur with the 4d, 6d groups as well? I am at a lack of understanding in this topic, I am just wondering what specific elements does this jump in a lower atomic radii occur. ...
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What is the 'ancestral term' in the LS coupling scheme?
On the physics.nist.gov site: http://physics.nist.gov/Pubs/AtSpec/node06.html
The table titled "Atomic structural hierarchy in LS coupling and names for the groups of all transitions between ...
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multielectron spin-orbit coupling and energy level
For multi-electron atoms for which the Hamiltonian (including the spin-orbit coupling reads)
$$H=\sum_i T_i-Z\sum_i V_i+\sum_i V_i^{\text{s.o.}}+\sum_{i>j}V_{ij}$$
The $T_i$ are the kinetic ...
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Moment of inertia for a triatomic molecule
What does the moment of inertia for a molecule mean? How is it useful? Most importantly, how would I go about solving it for a triatomic molecule?
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Modeling perturbations of a quantum mechanical system
I'm wondering how to properly perturb a quantum mechanical system.
I'm looking for a way to express the return to equilibrium of such a perturbed state, where the perturbation is in the Hamiltonian. ...
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Is the Springborg 6D phase space model used in modern molecular orbital modeling?
In a series of papers in the early 1980s, Michael Springborg explored an interpretation of the Wigner phase space function as an electron density in a six-dimensional $(q,p)$ phase space. He applied ...
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Has QTPIE ever been applied to 1D metals such as polyacetylene?
QTPIE is a fluctuating charge model that substantially improves modeling of polarization and charge transfer. I was curious whether it has ever been applied to 1D metals such as polyacetylene to ...
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Pauli exclusion principle and resonance
I've always been a bit uncomfortable with the concept of more than two electrons in a single orbital-like region(probability-wise) which occurs in resonance.
This seems to disobey Pauli's exclusion ...
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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 ...
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Non-integer hybridization
I've known that hybridization in distorted geometries is not exactly $sp^3$ or $sp^2$ or whatever. For example, $\ce{PH3}$ has nearly pure $p$ orbitals in the $\ce{P-H}$ bond, and the lone pair is in ...
