hethamulburton

hethamulburton's Profile Comments

Comments: 27, viewing 1 - 20

Athabasca wrote on Aug 26th, 2011 7:18am

hethamulburton wrote on Aug 23rd, 2011 at 1:54am :
No problem. Look for a class that makes you use programs like GAMESS, Gaussian, NWChem, Spartan, or Casino (I think that's a Monte Carlo program) and you'll be basically doing what I'm doing. And you'll never think of electrons (or orbitals) in quite the same way again.


Cheers for the recommendations man. I have a good friend a couple of years ahead of me who's majoring in computational physics, I'll ask him about it as well, see if any of the classes use those programs.

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Athabasca wrote on Aug 21st, 2011 10:48am

hethamulburton wrote on Aug 17th, 2011 at 4:07am :
To be honest, my lab has 6 people in it currently. 2 chemists, 4 physicists... the 4 physicists had zero previous experience with anything other than Windows software, like any other college graduate. I wouldn't say it's absolutely essential, but if you wind up in a lab that works with computers... that's a large chunk of your learning curve you've already tackled. Computational labs have THE largest learning curves and it never seems like you've tackled it.


Haha so it can't hurt it seems :P. I think there are a few computational physics subjects offered at my uni anyway. The stuff you're doing sounds really interesting so I'll probably try to pick those up as well. Thanks man!

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Athabasca wrote on Aug 16th, 2011 12:27pm

That all certainly makes sense. I have to say though...I struggle enough with just MATLAB as it is haha. I'm more of a pen-and-paper sort of guy I suppose. Never too late to learn though right? I plan on taking up a couple of computer science subjects next year in anticipation of perhaps doing some computational physics later on. Is that a good idea or would you think it unnecessary?

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Athabasca wrote on Aug 7th, 2011 10:19am

I think I understand. So it's more of a matter of, you have the framework there, and so it doesn't really matter what data you input, because the system can take care of it in time anyway?

I also get the impression then that your line of work is very innovative. If you're trying to go through QM rather than Bader analysis, then does that mean you have to write all your own programs and algorithms virtually from scratch? Is there a lot of research in this area?

I have to say man, everything you have told me has really opened my eyes to how little we know as a whole. I thought that all this stuff was virtually done and dusted but clearly it's far from that. Sorry for the late reply as well, went back to uni a couple of weeks ago and it's absolutely mental already.

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hethamulburtona wrote on Jul 23rd, 2011 6:02am

From the program we use (Gaussian09 in this case) we generate a cube file which is a 3D grid of the electron density. We throw that into yet another program that performs what's called Bader analysis and returns the charge distribution across each atom in the cube file (quantifies the charge transfer, where it went). We use electron density difference maps to visualize the charge transfer. In this case, it's the difference in electron density of the cluster - waters only - ion only. This figure shows where the excess charge is "flowing" for lack of a better word. My goal is to do this using quantum mechanics (calculate the charge transfer without Bader analysis) and then we're also interested in calculating hydration free energies, enthalpies, entropies, etc.

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Athabasca wrote on Jul 23rd, 2011 4:59am

It's certainly and interesting prospect to try and find a less basis-set-dependent method. Sounds a bit tricky to me though...wouldn't it mean reworking the mathematical groundings of QM so as to not be all about vectors in a Hilbert space, which intrinsically require a basis for computation? Perhaps I am thinking about this the wrong way; like I said I'm not all that savvy with this stuff yet ha.

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Athabasca wrote on Jul 23rd, 2011 4:20am

I see. So what determines which data you would use for a given simulation if you have all three types available to you? Is it generally preferable to use the theoretical ones derived from experiment or the arbitrary ones? I only ask because at mid-undergrad level anyway, most of the stuff is derived by considering one of those "arbitrary" models, with N atoms in a X by Y by Z box, although I'm aware that by the stage of "plugging the numbers in" the derivations themselves are all done and dusted. I'm also curious to know what the electron difference maps are. Are they "maps" in the mathematical sense or something else?

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Athabasca wrote on Jul 22nd, 2011 2:54am

Ah okay I understand. So, the numbers you feed into the system then, are they gained experimentally or are they sort of theoretical "guess"? Also you were talking about getting better methods for better results. I've been under the impression for a couple of years now that in some problems in QM it's impossible to achieve a 100% accurate result and you instead have to just approximate away using whatever method. Does the mathematics really prevent an exact solution in most cases?

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Athabasca wrote on Jul 18th, 2011 9:47am

Man that's so interesting. What you're doing sounds a bit like computational chemistry then (at least by analogue to computational physics)? I think it's wonderful you're so keen on it man. I feel the same way about physics and maths, but I'm only undergrad so I'm a bit of a noob. A goal of mine is to learn about exactly what you're doing, with the quantum structure of molecules and so on. I gotta say though, the programing sounds pretty tough. I've never been that much of a computer whiz; is it unrealistic to expect to find a job in theoretical science these days which just involves doing maths with pen and paper?

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Athabasca wrote on Jul 17th, 2011 3:55am

hethamulburton wrote on Jul 17th, 2011 at 6:33am :
Kind of... Most of our problems look at linking our atomic understanding to a molecular understanding. Or at the very least, letting atoms interact.


That's awesome man. What got you into that specifically?

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Athabasca wrote on Jul 3rd, 2011 10:57am

Man, theoretical chemistry. What exactly is that? I've never really heard of it before. Wouldn't you basically be doing theoretical physics?

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hide_the_beer wrote on Sep 14th, 2009 7:26am

Man, you bring down the hammer of clarity and reason in the Creationism vs. Evolution thread.
Respect.

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tushmeister wrote on Feb 9th, 2009 10:51pm

Ah awesome, thanks for taking the time to reply then!
And thanks for the song title, I watched the video again just for that!

Sounds like what I expect I'll be like in a few years time, I've enough arguments against them, I've provided enough sources before, I just never think I'll have to have the same argument (oft with the same person) a week later and have to repeat myself
Foolish me I suppose!

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tushmeister wrote on Feb 8th, 2009 7:47pm

Having began studying the Chemistry of the Cosmos only a few weeks ago, and having just covered the Big Bang, and evidence for it (Red Shift, CMBR, Light Element Distribution, Olber's paradox on a more philosophical note) can I just say the first link in your sig is absolutely brilliant, I've just read it through now and it's fascinating, thank you for sharing it with people!

And may I ask, in the video you link to in OWNAGE (FINALE), Requiem for Genesis, what is the song playing? I watched the video but it was mostly things I already understood and knew, the music however kept me watching, a very good tune indeed :)

You seem a very intelligent person from the little I've seen, I'm considerably grateful to share these forums with someone such as yourself, I can only hope I gain from your presence in the Religion thread! (Which judging by Bisheks response, you used to regular? As I now do :) )

I seem like I'm brown-nosing, I honestly don't mean to do it for favour or recognition, just to state what I see

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ottoavist wrote on Jul 3rd, 2008 6:36pm

http://www.ultimate-guitar.com/forum/showthread.ph p?p=15074175#post15074175

check out my last post. thoughts?

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CORT noob wrote on Feb 27th, 2008 6:49am

lulz 666 profile views.

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Carswell98 wrote on Feb 25th, 2008 5:37am

I'm watching the vid in your sig, good stuff

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AAAAAAAAAARGH wrote on Feb 19th, 2008 3:20pm

Hey, don't think I fancy you or anything... But... Well... What i'm trying to say is... You're really neat. Ya know?

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Chris.Rock.Art wrote on Feb 13th, 2008 10:19pm

He is neat------:D

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omegasus wrote on Feb 13th, 2008 9:43pm

Hey that's cool and/or neat!

Let's copulate.

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