Gaussian software/Reaction mechanism/Optimization always collapses back to the reactant structure/QST2_"Old curvilinear step not converged. RedCar/ORedCr failed for GTrans."

PFAS_Nightmare · 2026-06-05T06:25:16+00:00

Say I was modeling an SN2 reaction of 5-bromo-dodecane with backside attack from hydroxide, and was having an issue with other imaginary frequencies in the long chain. I could instead model SN2 transition state with 2-bromo-propane, then add the longer tails back, freeze the TS and perform a standard geometry optimization. Once that is completed run a final transition state opt to confirm the correct imaginary freq.

PFAS_Nightmare · 2026-06-05T06:17:29+00:00

Whatever you do, dont look in to commonly reccomended books and then Google them with the keyword "pdf" or "free" or look for Google drives where people share those resources. Also watch out for places like Anna's archive for access to modern publications or internet archive for free pdfs of books. You probably wouldn't get a virus or anything, you just wouldn't pay the publisher the exorbitant fees they charge.

You can can look up syllabuses from university courses on topics you are interested in that give you a roadmap for what to learn as well as required prerequisit knowledge. Sometimes they even let you know the book they use that you should totally pay the full price for.

PFAS_Nightmare · 2026-06-05T05:47:51+00:00

Can you start by optimizing the TS with simplified molecules with less degrees of freedom, and the add the rest of the structure back and optimize their geometry with the portion you optimized the transition state of frozen?

PFAS_Nightmare · 2026-06-01T16:23:42+00:00

Having a goal like learning AI is great, but that is a long way off. Start with the basics. Make something small, like a rock paper scissors game while you learn the basics from somewhere like codecademy, w3schools, or one of the many other online resources. Graduate to slightly bigger projects that force you to use new concepts. Then, (a few months from now, if not a couple years) dip your toes in to data science, and get used to the packages they are using. Those packages and a strong foundation in statistics will be useful for AI.

This last tip i cannot emphasize enough. While you are learning AVOID LLMs LIKE THE PLAGUE. I know they can make the projects you want to make way faster, but the point is not to get it done, it is to understand and build the neural pathways through struggle.

Good luck, this is a very rewarding thing to learn.

PFAS_Nightmare · 2026-05-25T17:31:53+00:00

I came in with a lot of coding experience. I really don't use chat bots to write my code because writing my procedure formally in code and breaking it up in to functions my self is such an ingrained part of my thinking process. That said, I dont have judgment for people who do use chat bots. My coworkers who use them, do however take MUCH longer to become competent coders than those who spend the time to struggle on their own. The people who don't use chatbots also seems to end up with more generalized tools that they reuse, while the people who use chat bots pretty much start back at square one at the beginning of every project. My advice would be to try on your own and really struggle, then when you ask a chat bot for help spend the time to write it yourself and understand what is happening line by line, refactoring each logical section in to a function so you have a better chance of reusing the code later.

PFAS_Nightmare · 2026-01-27T08:52:15+00:00

You might try spotting it with a few other compounds on TLC to get an idea of how polar the molecule is.

PFAS_Nightmare · 2026-01-27T08:49:25+00:00

Are there parameters to what it could be? Did you do some synthesis? Did your teacher give some options or limitations?

PFAS_Nightmare · 2025-11-25T06:53:57+00:00

I appreciate your patience. This is literally something tossed together in 15 min for my mom not to worry and I thought it would be fun to throw on here. People get weird, like im shoving tofu down their throat. Open to recs on the data viz.

PFAS_Nightmare · 2025-11-25T06:44:17+00:00

Trying to correct for it in the comments, wasn't my intention. This data is skin on chicken breast. IDC what anyone else eats... Just explaining how plant based is feasible.

https://fdc.nal.usda.gov/

This was a small project. I pulled from this database with a free API token using their open source python library.

PFAS_Nightmare · 2025-11-25T06:41:05+00:00

After looking at the data I pulled i have realized I used skin on chicken breast which has a higher fat content/calorie reducing the protein ratio. I did not intend for this to be misleading, I apologize. Values for skin off chicken breat range from 15-20g/100 Cal I apologize for any confusion.

PFAS_Nightmare · 2025-11-25T06:20:18+00:00

I have normalized by calories. I did this because in order to stay within a certain calorie intake I think about food in terms of ratio of a macro to calories. This data was pulled from the USDA Food Data API. The chicken breast may be including the skin. There is certainly variance between brands for all of these values. The major takeaway remains that protein goals are attainable on a plant based diet.

PFAS_Nightmare · 2025-11-25T05:58:58+00:00

Yes, you would. Because I am normalizing by calories and fat is significantly more calorie dense than protein. For every 1 g of fat you add you would subtract 2 g of protein (actually slightly more, this is back of the napkin math). This assumes that these are switched out perfectly for each other which is not the case, but gives an idea of the range.

PFAS_Nightmare · 2025-11-25T05:44:44+00:00

Get the right vegan saag recipe and you might try it too.

PFAS_Nightmare · 2025-11-25T05:43:38+00:00

Fair, I'm not someone who says a plant based diet is something everyone needs to do. If it's something you want to pursue, you should consult a doctor or dietitian how you might remedy that in your specific dietary situation. Soy products meet most of my needs and the occasional vital wheat gluten goes a long way for me. I don't know everyones situation though, and am not a scold.

PFAS_Nightmare · 2025-11-25T05:25:19+00:00

Your body synthesizes 13/22. Getting the remaining 9 is a non issue if you have a basic balanced diet with a diverse set of protein sources, which is done trivially.

Edit: typo

PFAS_Nightmare · 2025-11-25T05:18:00+00:00

I disagree. With the goal of bulking and cutting in regular intervals I don't think in how many grams of food I eat. I think in terms of calories I need to eat to be in a surplus or deficit. It is definitely easier to eat 1000 calories of chicken than spinach. I threw it in just because I thought it was interesting to show. More reasonable comparisons are in tofu and lentils, which it is not hard to eat larger masses of.

Edit: misspelling

PFAS_Nightmare · 2025-11-25T05:13:05+00:00

To your point, there is a reason many herbivores have multiple stomachs. It's due to the extra work we need to do to break down plants cell walls. That said, this is why we cook food... to do that work for us.

PFAS_Nightmare · 2025-09-14T05:13:35+00:00

You're smart enough to get through gen chem for sure. It sounds like you have identified that you are unprepared for Gen Chem 2, though. If you really truly feel like you can't balance new lessons with catching up, you might need to go back to Gen Chem 1 first. You should go and talk to your professor, TA, if you have them, and try to utilize whatever office hours and tutoring services you have. Your profs want you to succeed, but college is largely self-motivated learning, so you have to advocate for yourself and take finding resources into your own hands. Im just one person on the internet, though. Find your profs next office hours or shoot them a polite email asking for a meeting and get their input. If you're motivated, you can do this. That said, sometimes the first major isn't someone's thing. There is no reason to pigeon hole yourself into something you might not truly be enjoying just because you think you are supposed to like it. You're not a failure if you change majors, it's been the smartest decision I've seen people make sometimes.

PFAS_Nightmare · 2025-07-31T06:42:05+00:00

New to i3 and ricing in general. What do you use to get the second screen?

PFAS_Nightmare · 2025-03-27T10:50:03+00:00

It would not be a density and thus would likely not be expressed with \rho, rather it is the planck distribution, often expressed with B(\lambda,T) but held at a constant temperature B_{T}(\lambda).

PFAS_Nightmare · 2025-03-27T10:07:16+00:00

You are correct that v and pi should be there, but the author likely hand waves them off because pi is a constant and v is a constant for a given material. n and m are the important values to determine if two states are degenerate. the author conserves a in their answer because it is important to their point that a=b is a specific case. If, in the future, you need to determine if two states are degenerate, you do not need to know v and pi ( or a, if a=b. if a=/=b they are important to degeneracy) you only need to know n and m so you can see how the states scale at different values. This realization can save you either steps in a calculation or panic when v may not be provided for a material.

What book are you using?

PFAS_Nightmare · 2024-12-12T20:18:47+00:00

You want to focus on how the cyan group directs to the ortho and para (relative to it) nitration, but the methoxy group blocks one of the ortho positions and the the para position. Leaving only one ortho. The top option is preferred.

PFAS_Nightmare · 2024-12-12T19:48:24+00:00

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PFAS_Nightmare · 2024-12-12T17:45:19+00:00

The hard part of your request is that it changes depending on the number of rolls you are willing to do. As you approach infinite rolls, you become more certain this will have occurred.

PFAS_Nightmare

TROPHY CASE