The Periodic Table

@LordStryker Is entropy diorder?

@user223679 Depends on who you ask :)

@user223679 What is diorder? Dimer of order?

disorder.

We generally use disorder as a way to explain the concept of entropy (many people blankly stare when you talk about stat thermo).

6:20 PM

@LordStryker And is explaining in that fashion correct?

In Chemistry we explain a LOT of things in a way that isn't correct, both technically and/or grossly.

But if we do explain things incorrectly to get a point across, we must always be mindful of pointing out where the faults are in the explanation.

I do this in my G. Chem. classes all the time.

I like to say that many of the rules we learn in chemistry are simply guidelines and that there are exceptions to nearly every rule (or problems with every explanation)

This is what made me ask : entropysite.oxy.edu/entropy_isnot_disorder.html

@LordStryker You're just like my chemistry teacher!

i.e. You guys are both awesome!

So if you're a chemistry major and you advance to upper level chemistry classes, you'll be told many times "Now here is something you learned in G. Chem. and now we're going to learn how its completely wrong."

Thanks @M.A.Ramezani :)

My chem teacher made me like chem, while I was indecisive about which to love the most between chem and math and physics and bio.

6:23 PM

You know what they say about chemistry. Chemistry is the CENTRAL science.

Am I weird for only liking Math and chemistry? Perhaps a quantum physics as well.

Everything oscillates around chemistry. Chemistry is equilibrium.

@Alizter Everyone is weird.

No one's like another.

Except for particles

You cannot distinguish them

Details - pfft.

BTW @Alizter where are you from?

UK

6:27 PM

Cool. @Bon's from UK too.

now @M.A.Ramezani nominate, NOMINATE!!!!!

Wut?

Oh it's you @san.

Chemistry is simply condensed phase physics.

it is i

@santiago Well it's over.

Everyone that should've nominated nominated.

6:31 PM

@LordStryker help me nag @M.A.Ramezani to nominate

@san He does not wish to nominate.

@santiago Tough luck!

awwwwwww

lol

in other news, my neighbour got robbed

Rubbed?

robbed, burgled

6:37 PM

I know, but it's fun to play with words.

Is there insurance to pay back?

woooo! The code works!

and its beautiful!

yup, they're insured

@LordStryker which code?

@santiago Phew

@santiago Code I've been writing all day

@LordStryker What do you write it in?

6:39 PM

csh

:)

I approve

What does the code do?

588 lines of code

@san Great question!

Cool.

Are you familiar with things like potential energy surfaces or potential energy curves or reaction mechanisms on a PES?

6:40 PM

@santiago One word: Minesweeper.

@LordStryker I thought you were going to say "I don't know yet".

a bit

Okay so A -> B

@Alizter that's the best type of code!

Q: What's the bonding in diborane - hydrogen chloride?

Good people!

0

I was researching and Googling and researching again, about this very interesting molecule: Diborane. Then I faced a very interesting structure, something that I have never seen before. Something that turns up lesser than 50 results in Google, most of which are behind paywalls, and thus leave me...

inorganic-chemistry bond

6:41 PM

on a PES, we would have molecule A, a minima, being connected to B, a minima, through a transition state (a molecule with exactly one imaginary mode of vibration) on a potential energy surface.

Posted.

@M.A.Ramezani upvoted

NOOOOOOOOOOOOOOOOOO!

@M.A.Ramezani Is that not van der waals

Ooooh BTW I'm not sure about what tags to add.

@Alizter Couldn't be.

The name's weird.

6:42 PM

@LordStryker continue...

Now, its pretty easy to analyze this sort of reaction mech. manually to ensure that the minima are indeed connected.

But say you have a very busy potential energy surface with many minima and TSs

@M.A.Ramezani or london bonding as its called elsewhere

@Alizter No no.

I don't think it's intermolecular forces.

It can be very difficult to not only examine this manually but potential energy curves can become problematic if you want to illustrate what all is connected.

So the idea is to simply look at the PES not as a 2-D slice but from a birds-eye view, sort of like a connectivity map.

They were written together. Diborane - hydrogen chloride.

That's not how you address van der waals forces.

6:44 PM

So I wrote code that will examine the 'connectivity' of an arbitrary set of molecules that have been characterized at the same level of theory based on ENERGY and the unweighted Cartesian coordinates.

If the energy and root-mean-sq. deviation (RMSD) of the coordinates fall within a particular set of thresholds, we will count it as connected.

Cool!

Essentially, given a set of molecules (TSs and minima), my program will automatically generate a connectivity map of the PES

the actual connectivity map hasn't yet been coded but everything we need to determine connectivity is now complete

very cool! Are you going to make a program available, once complete?

@santiago I don't see why not.

@Lord you might be interested: lb.chemie.uni-hamburg.de/static/CN/2_D_dibor.php?content=166/…

6:46 PM

It will use graphviz (graphviz.org) in the end.

@M.A.Ramezani Oh, I built my dimer with the hydrogen from HCl pointing toward the diborane :\ (bucky-central.me.utexas.edu/RuoffsPDFs/26.pdf)

I can fix that later. It would be a useful comparison.

@LordStryker that'd be brilliant!

Look at space filling model of diborane

its funny

@LordStryker What's its name gonna be?

lol @M.A.R right now its simply called "graphviz.sh"

6:49 PM

but I might call it, "LStrykers_kickass_chemistry_software.awesome"

2

@Alizter Oh that molecule is dirty!

I second that!

We need that photo enhanced

To quote professor Homer Simpson: Why you little...!

@LordStryker YES!

6:51 PM

hmmm I like that molecule....I like it alot

STOP!

@Alizter Needs more CURVES!

(for science!)

I wanna flag these as interesting...

z-1,2-dibromodiborane

The central molecule needs to be bigger - for scientific observation of course

6:53 PM

@M.A.Ramezani This paper always makes me giggle: piwet.pulawy.pl/bulletin/images/stories/pdf/20084/…

4

tbh I originally thought it was funny because it looked like people hugging

but then you guyses

People hugging...Seriously?

yes, two people hugging....... of course.....

@LordStryker What the @#$#@!@#$#@!$$#@!!!

Really fat people hugging

Atom colours

6:56 PM

It looks like when I wanted to make a salad but ended up screwing stuff.

@LordStryker imagine that winning the Nobel Prize

@M.A.Ramezani Incredible isn't it?

@santiago Didn't it?

@LordStryker This is what we get for science!

I've seen worse

> Key words: bi@ch, va@ina, Mycoplasma canis.

6:59 PM

@M.A.Ramezani when you search "diborane - hydrogen chloride" your question is the second result.

Hah!

YOU'RE FAMOUS!

No, I'm not signing your back.

@M.A.Ramezani signing my back? You'd have to get through the hair first

INTERESTING:

This paper calls it a hydrogen bond, this one provides structural information — ron 2 mins ago

7:01 PM

Apparently HCl and B2H6 react to form B2H5Cl and H2

@Alizter Shhh. @Lord doing SAPT thingy.

@M.A.Ramezani How can it be a hydrogen bond?

I thought chlorine wasn't electronegative enough to be in the special club?

It can't be.

So it is probably dipole-dipole right?

@Alizter You're talking about Cl, I'm thinking about B

@Alizter I don't think it's anything like that.

7:03 PM

In that case it's probably glue.

Yep.

Glutamine Econazole.

Mmmm...Fried eggs...

I am thinking those hydrogens in the middle are very exposed

Incase a cheeky nucleophile were to come along

@Alizter diborane is non-polar

7:09 PM

@LordStryker How is the program?

It would be dipole induced-dipole

@Alizter It is good. I'm having a graduate student code the rest (creating the graphviz input)

Q: What programming languages do mathematicians use?

38

I understand this might be a slightly subjective question, but I am honestly curious what programming languages are used by the mathematics community. I would imagine that there is a group of mathematicians out there that use haskell because it might be more consistent with ideas from mathematic...

soft-question big-list computer-science software

read the first answer

@Alizter Clever indeed though more appropriate as a comment.

It was the old days when nobody was too serious

Sometimes I miss the old days.

7:15 PM

lol

The question was closed as no longer relevant

have not seen that before

@Lord The first paper Ron linked to speaks about diborane (4), while I'm looking for the diborane (6) "version". There's some info here. The interesting part is that in computing molecular mass, it takes both HCl and B2H6 into account. — M.A.Ramezani 17 secs ago

@M.A.Ramezani Which diborane-HCl dimer are you interested in? Are you strictly interested in the one you posted?

Yep.

hmmm I may have a question brewing

7:17 PM

With Cl pointing toward the H's on diborane?

yes

Okay just making sure. Calculations are not cheap you know. ;)

I'll go ahead and look at them both.

what the....?

hmmmm okay, I have a context for a question...but....

But you're not sure if I'll downvote? I'll downvote, chill.

lol

7:23 PM

Downvotes are great only when I dish them out

it would be a question based on me thinking "what the flying fruitbat are they talking about?"

About what

Questions about fruitbats should be asked on bio se

lol

helium hydride

@M.A.Ramezani You should look and see if someone has characterized an HF-H2O or HCl-H2O dimer

Assuming the proper orientation, it would be very analogous to your HCl-B2H4 complex.

@LordStryker Thanks for the suggestion!

I'll look.

7:27 PM

If I shoot a helium atom with a proton does it become helium hydride or an isotope of lithium?

@Alizter Neither. It simply becomes angry.

It'll die.

You murderer!

Is neon more inert than helium?

Nah. He is more inert.

I just asked him.

@santiago The bond order is 1/2, right?

That's what I remember from the MO scheme.

helium is more inert.

7:30 PM

bizarre article - stay tuned for the question

It is less polarizable than neon.

physics.udel.edu/~msafrono/Papers/ICCMSE-2010.pdf

It should be. Polarizability increases with volume increase.

That's why you get $\ce{XeF4}$.

Yes that is what I thought

but I remember reading somewhere that neon was more inert

But $\ce{He2}$ is only possible at some -200-something Ks.

@Alizter Screw that somewhere...How dare they not agree with me?!

@Alizter blogs.nature.com/thescepticalchymist/2013/05/…

7:33 PM

okay, question posted - am hovering over the delete button

Helium has two valence electrons while neon has 8. That is the subtle difference.

Quite interesting.

@san nevermind. found it

@santiago The answer to your Q is - Under healthy conditions.

hold on to your corsets - chemistry.stackexchange.com/questions/32717/…

@M.A.Ramezani or "Obviously the right conditions" ;)

I can say that under the exam conditions, nothing is stable.

7:35 PM

lol

Oooh, BTW, I only have one exam left.

Guess which exam?

You know, its funny. I get super nervous before administering an exam.

I worry about two things: The well-being of my students and typos.

The last one is quite a beast to deal with.

I get nervous posting questions

@LordStryker This is very interesting. Both the examiner and examinee get nervous before an exam. Then why do we even have the effing exams?

O.O

@LordStryker There was a missing comma in one of my exams and I was really worried because the English didn't make sense and I thought I forgot how to understand English.

7:37 PM

@santiago You're not alone.

@M.A.Ramezani To celebrate the acquisition of knowledge of course!

@Alizter No matter how many hours I pour over my exams (which I write from scratch), I always seem to miss something. Usually its trivial but a couple of times it was not.

That's a spooky celebration. Like celebrating Halloween.

I like asking questions, but...

@LordStryker Don't forget the questions.

but..,

@LordStryker What were the not-so-small typos?

7:39 PM

Well say you have to work out a numerical problem and I give you a multiple choice exam along with a number for that problem that is printed incorrectly.

if that typo makes it through then I'll have to throw the question out.

@LordStryker Why multiple choice?

Hah!

which isn't necessarily fair for the students who invested their time into doing the problem vs. those that skipped it

@Alizter I teach two sections each with ~200 students all on my own. There is no way I can hope to grade 400 written exams by myself.

@LordStryker This is what usually happens to our math teacher.

ah

@LordStryker use graduate students?

7:41 PM

I don't have any. I'm a post-doc.

He then solves it: He who solved the typoic question gets an extra +1 score.

@LordStryker I heard they go for cheap these days

Just need to know where to look

You might need to find a black market dealer

If we have a an english language learners site

Why not have an X learners site?

for X homework

but then again

Homework site doesn't work.

all of these sites are for learning

No really. It doesn't.

But we do have a homeworks.SE.

Its name is math.SE.

7:46 PM

Ouch

Im from there

They are almost religious about it now

Hah! Then you agree with me.

@Alizter So, they're protective about having homework?

I remember the crucifixion of the homework tag

There was a mass retagging

It was the largest tag

which paints a bad image for new comers

Still, homework keeps comin' and gets answered there.

There are two types of people there

Those who don't answer homework questions and flag/close

and those who answer and say yipee with all there points

And rep whores.

Sorry, I hate some users there. Makes me biased.

7:50 PM

It appears as if everybody is helping them when in actual fact most users are voting to close

including me

but then we have very blurry lines

Cool! Thumbs up

like when a question is genuinely difficult and interesting but has no effort

@Alizter Yes. It's hard to decide if one Q's homework or not in math.SE. I understand.

and we get these crackpot answers

A really hard integral

the answer

no working

Nobody knows how

in We love math, physics, chemistry and random talk., Jun 6 at 18:19, by M.A.Ramezani

A HW chem question looks like an imbecile trying to use you and get the hell of the answer outta ya, but a math Q, even when it's obvious that it's HW and its OP is a help vampire, looks like a delicious puzzle that asks solving.