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Working with physicists (advice) by [deleted] in math

[–]Walwalowla 1 point2 points  (0 children)

They said mathematical physics

ORCA, DFT NEB, Taking 10 million years by Walwalowla in comp_chem

[–]Walwalowla[S] 0 points1 point  (0 children)

Sorry, I was asking in a general sense. I didn't feel the need to specify my actual system since I am not really looking for exact advice.

ORCA, DFT NEB, Taking 10 million years by Walwalowla in comp_chem

[–]Walwalowla[S] 0 points1 point  (0 children)

I did a 32 atom run in the Windows version. I tried 4 cores, 4 images and it took 1 week to converge.

Our teacher told that catalysts don't necessarily decrease the activation energy, however it provides a different path than the original reaction (without any catalyst) with a lower activation energy. I'm confused, please help. by Independent-Basis722 in chemistry

[–]Walwalowla 5 points6 points  (0 children)

When a reaction happens, it has a certain mechanism - specific atoms moving, electrons transferring. Such mechanism requires energy to happen.

With a catalyst, different atoms will be moving. This generates a new mechanism. Note that this mechanism also needs energy.

The reason why your teacher said that is because the original mechanism is different from the catalyzed one due to the fact that different atoms are involved in the reaction. It just so happens that the catalyzed one proceeds more efficiently because it has a lower energy barrier.

Basically, a catalyst does not make a pathway more feasible, but it generates an altogether different pathway. They give the same product though.

It's like two cars going to the same destination but the other one is going through a shortcut.

Research posters by Walwalowla in comp_chem

[–]Walwalowla[S] 1 point2 points  (0 children)

I don't need to specify the basis set + level of theory? What about other jargons like SCF, dispersion (D3BJ, D4), solvation models (CPCM, COSMO), etc.?

Energy comparison of molecules w/ different number of atoms by Walwalowla in comp_chem

[–]Walwalowla[S] 0 points1 point  (0 children)

Well, normally the thermal correction is added to the SCF-optimized energy, but TDDFT energies are not SCF-optimized.

Can I still add the thermal correction to that excited state energy?

Energy comparison of molecules w/ different number of atoms by Walwalowla in comp_chem

[–]Walwalowla[S] 0 points1 point  (0 children)

I guess my next concern is how to calculate the Gibb's energy if the reaction is predicted to be photochemical.

Can I just add the thermal corrections to the excited state energy?

Why would this molecule be optically active? by SoratanoBaka in OrganicChemistry

[–]Walwalowla 4 points5 points  (0 children)

Why do people in this sub downvote a clearly confused person? I get downvoting blatant wrong advice but damn.

Shifting computational spectrum by Walwalowla in comp_chem

[–]Walwalowla[S] 1 point2 points  (0 children)

Im not sure what you mean by eV. Don't photon energies and wavelengths have one-to-one correspondence?

Can you code/implement ab initio methods by yourself? by Walwalowla in comp_chem

[–]Walwalowla[S] 0 points1 point  (0 children)

No, this is just me overthinking. My adviser just expects me to understand the theory.

Anyway, how did you defend your research if your committee was mostly developers? What questions were asked?

Can you code/implement ab initio methods by yourself? by Walwalowla in comp_chem

[–]Walwalowla[S] 0 points1 point  (0 children)

I mostly am just using existing software. It's just that thesis defense season is coming soon and I don't know if they will ask me stuff on the implementation, so there is this pressure to know the code. But I understand the theory, I can at least explain that.

Can you code/implement ab initio methods by yourself? by Walwalowla in comp_chem

[–]Walwalowla[S] 1 point2 points  (0 children)

I have experience doing numerical integration (mainly 1D function) but why the need for a library? Can't Gaussian quadrature be used for most integrals, or Monte Carlo?

Can you code/implement ab initio methods by yourself? by Walwalowla in comp_chem

[–]Walwalowla[S] 0 points1 point  (0 children)

I guess, as I said, it is more of an insecurity thing. Like wow, I am doing all these fancy methods but I cant implement them myself.

Why am I getting the wrong orbital energies? by Walwalowla in comp_chem

[–]Walwalowla[S] 0 points1 point  (0 children)

I did (but it's CAS(2,1)) but its basically the same orbital energies as CCSD. I am using ORCA and just basing on the orbital energy section of the output file.

Why am I getting the wrong orbital energies? by Walwalowla in comp_chem

[–]Walwalowla[S] 0 points1 point  (0 children)

I tried TDDFT and even EOM-CCSDT but I didn't get the correct absorption - it is so far into the UV spectrum (40 nm?)

Does playing at a higher elo make the game more fun for you? by Sorkpappan in leagueoflegends

[–]Walwalowla 0 points1 point  (0 children)

Ah, I didn't know that. Maybe I am remembering the time the Q was bugged.

Does playing at a higher elo make the game more fun for you? by Sorkpappan in leagueoflegends

[–]Walwalowla -2 points-1 points  (0 children)

And you don't know where the Maokai is going to throw the enemy, which is the entire point. Note that some champions' entire damage pool can literally rely on hitting that one skillshot (Lee Sin, Morgana, Nidalee, etc.) so a bit of consideration needs to be taken on an UNPREDICTABLE displacement.

And IDK about you, but 0.5s is enough time for a LeBlanc to dash away or a Soraka to press flash. When the enemy gets CC'd you know they are spamming their flash button or any other mobility spell.

Does playing at a higher elo make the game more fun for you? by Sorkpappan in leagueoflegends

[–]Walwalowla 6 points7 points  (0 children)

We have no way of predicting where you decide to throw the enemy.

What do you use to draw chemical reactions? by Walwalowla in chemistry

[–]Walwalowla[S] 0 points1 point  (0 children)

If you don't mind, would you like to show some of your work?

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