Unanswered Questions
1,264 questions with no upvoted or accepted answers
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Reason for 19F NMR of OsO2F3 chemical shift
I have been learning that [OsO2F3]+ shows two signals on the 19F-NMR spectrum. There is a doublet and a triplet which accurately depicts that there are two axial fluorine and an equatorial fluorine ...
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Why Car Parrinello Molecular Dynamics doesn't need an SCF calculation at every time-step?
Reading the various terms of the Lagrangian in CP-MD I'm trying to understand why there is not an SCF procedure hidden there.
In fact, it seems to me like the second term of the Eulero-Lagrange ...
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How can oxygen make a coordinate bond in O3 without vacant orbital
I was taught that for the formation of a coordinate bond the first condition is that the donor atom must have a lone pair of electron and second condition is that the acceptor must have a vacant ...
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Trend of effective nuclear charge down a group
Does the effective nuclear charge decrease down a group? Many online sources,including Wikipedia show this conclusion with the calculated data. But our teacher told us and again some online sources ...
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Reason of screening effect
I am totally confused about the screening effect. Is it because of the repulsion of inner electrons which ultimately reduces the net force of attraction for the outer electron , I'm pretty sure that ...
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How to Prepare Vanadium (Na3VO4) solutions buffered at pH = 7.5?
"I need to conduct adsorption studies on Vanadium using various substances like biochars and nanooxides. To prepare Vanadium solutions up to 320 ppm with a pH buffered at 7.5 using PIPES buffer, ...
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Gaussian Program Error for Linear Triatomic Molecule
I am trying to calculate the Hessian and vibrational frequencies of OCS (and eventually some anharmonic properties) with Gaussian09. However, the program always fails and I end up with the following ...
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Sodium zincate reaction
does adding zinc chloride into the solution of sodium zincate formed by the reaction of zinc chloride and excess of sodium hydroxide form the precipitate of zinc hydroxide ? I mean does sodium zincate ...
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Why is silicon dioxide a network solid while sulfur dioxide is a molecular gas
In my understanding sulfur dioxide’s Lewis structure has one lone pair on the centre atom (sulfur) with one pi bond to each oxygen atom, while silicon cannot form these silicon-oxygen pi bonds. Both ...
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Bicarbonate concentration in the RO permeate
I am facing a challenge since long ago, but have not been able to find a suitable solution for it. Please share your thoughts if you have the knowledge or experience in this area.
I am running an RO ...
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Is the $2p$ RPD defined along the z-axis?
In MIT $5.111$ class (lecture $6$), we are to compare the most probable radius of a $2s$ orbital and a $2p$ orbital. The graph used by the professor represents the RPD versus $r$:
My question is: in ...
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Short-circuiting an electrolytic cell with metal dendrites and observing interesting chaotic 1/f noise
While conducting home experiments on the electrolytic deposition of copper in a micro-gap (2-3 mm), under a microscope (x40) I observed interesting effects of short-circuiting by metal dendrites of ...
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Doubly occupied orbitals in quantum chemistry? (openfermion.org)
I am interested in diagonalising the fermionic Hamiltonian of small molecules, such as LiH in second quantisation.
The Hamiltonian is
\begin{align}
H(R) = \sum_{ij} h_{ij}(R) a_i^\dagger a_j + \frac{1}...
- 111
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Finding the relative position of the molecule in the adsorbate and adsorbent by minimizing the Hamiltonian
I am trying to model an adsorbing process (or more precisely, Heterogeneous catalysis process between solid catalyst and gas reactants). One of the step is to minimize the Hamiltonian by optimizing ...
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Does copper(II) hydroxide dissolve in ammonia solution?
According to University of Oregon — Chemistry Interactive Demonstrations and Educational Resources — Copper-Ammonia Complex, the equilibrium constant for the formation of copper(II) hydroxide is ...
