All Questions
Tagged with quantum-chemistry physical-chemistry
332
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Do Electron-Withdrawing-Groups give an hypsochromic shift or a bathochromic one? and why?
I'm not familiar with this topic,but i know that bathochromic shifts occur when the energy gap between energy levels of the substituted molecule, are lower than the unsubstituted one;viceversa ...
- 19
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52
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Absurd result for the selection rules in the three-dimensional PIB
By using time-dependent perturbation theory and some simplifying assumptions, we know that a transition for a charged particle $q$ from a quantum-mechanical state $m$ to $n$ is allowed if and only if
\...
- 3,684
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168
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Wave function in Schrodinger's model
I am trying to wrap my head around the Schrodinger's quantum mechanical model of an atom.
According to the NCERT$^1$, the Schrodinger's equation is given by:
$$\hat{H}\Psi=E\Psi$$ where $\hat{H}$ is ...
- 828
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Does ionisation change the physical/chemical properties of an atom?
From what I have learned, the number of electrons on the outermost shell (called the valence electrons), determines the chemical properties of an atom, this is why elements in the same group have ...
- 35
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95
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Quantum Mechanics expectation value help
I am working on the following question:
I've so far done the first part of a, finding $H_{so}$ in terms of J L and S. I'm struggling to see how to relate that to $E_{LSJ}$ as it involves the ...
- 11
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Mechanism of adhesion of particles on solid surfaces [closed]
What is the mechanism of adhesion of particles on solid surfaces?
How does anything stick to anything, for that matter?
Why does cigarette smoke stay so stubbornly on our bodies?
Why does perfume also ...
- 37
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1
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95
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How to compute solvent reorganization energy in Marcus' non-equilibrium approach?
I try to solve the following equations for some system solvated in the water. The goal is to obtain value in kcal/mol. Unfortunately, I cannot reach the desired output. May someone help me?
The ...
- 103
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Determination of ground state energy that has the same L and S values
Determination of the energy of a multielectron atom in the ground state can be estimated using the atomic term symbol which involves the values L, S and J. If an atom has the same L and S values ...
- 11
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How to perform NBO calculations at each point while scanning the bond length?
For a given bond, I would like to perform an NBO calculation for each structure while scanning the bond lengths.
Can I use Opt=ModRedundant in combination with pop=nbo? Simply specifying both ...
8
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2
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612
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Mulliken Labels: How do I tell apart E, doubly degenerate, symmetry apart from T, triply degenerate, symmetry for a molecular orbital?
With A and B, it's pretty simple. If you rotate the molecule about its principle axis to where the orbitals line up, and the signs change, it's Mulliken label has a B. otherwise, it's A.
I heard E ...
- 109
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Why is cyclohexane more polarizable than benzene?
Looking at figure 4.2 here, we can see experimentaly that cyclohexane is more polarizable than benzene.
Why is this the case?
Intuitively, I would think that because the orbitals in benzene are more ...
- 31
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181
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Term symbols in transition metals and lanthanides
Hello I was researching a little about term symbols of lanthanides and transition metals and have got two questions.
It is known that lanthanides don’t follow LS-coupling, but instead JJ-coupling. ...
- 383
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Eigenfunctions of total angular momenta as linear combinations of Slater-determinants
In the Hartree scheme for many-electron atoms, the approximated Hamiltonian (in a.u.)
$$\hat{H} = \sum_{i=1}^Z \left(-\frac{1}{2} \nabla_i^2 -\frac{Z}{r_i} + V_\text{H}\left(r_i\right)\right)$$
is ...
- 41
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Reduction of direct product representation
When we do the reduction of the reducible representation generated from the total wavefunction expressed as product of MOs of appropriate symmetry, we can find the direct sum of more than one ...
- 101
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54
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Group theory and exact Eigenfunctions of Hamiltonian
I think I've understand why the real Eigenfunctions of Hamiltonian belong to a given irreducible representation and I've read that also MOs have to transform as irreducible representation due to the ...
- 101