Wednesday, March 13, 2013

Introduction and stuff

For starters, yes I am insane and yes I am a quantum chemist. No, there is no direct (proven) correlation between the two. I have had major head trama before in my life (true story) but they say I was like this before my accident. As a quantum chemist I've been compared to the Dark Side, Nikita Khrushchev, the pied piper, and Trent Reznor, all of which I am very proud (due to the context in which I was compared, not because I like all of them by any means).

This is a place for me to air my different thoughts about what I'm working on and perhaps share something humorous (or even useful, heaven forbid) with someone else. If you happen to read this and there's something where you say "Gee Wally, that sounds like a great idea!" Much like in the TV show, I cannot be held responsible for any damages that may occur to you if you try it. I also make no claims to originality of the content here, and most likely I have stolen it from somewhere else along the way, I just don't remember, otherwise I'd give a reference.

I'm working on writing a routine to form the Hessian matrix and then diagonalize it to get the eigenvalues and eigenvectors. Simple enough, right? Oh no. I have no clue what's going on right now. Sometimes it works, other times it doesn't, other times I think my code is going to peel itself off my screen and come attack me for butchering it so much and so many times over. So far this was for problems larger than I was willing to do by hand. The smallest matrix that is still a real example is a six by six (that's 720 terms in your final expression before you simplify, and it's a sixth degree polynomial equations you will have to find the roots of) and I'm not that bored, even if I have nothing else to do right now. So I made up a toy problem and created a 3x3 matrix, diagonalized it by hand and got the eigenvalues. I then plugged it into my program and ran it and low and behold I got the correct eigenvalues. Okay, so my diagonalization routine is working. Perhaps the problem is in my routine that generates the Hessian. Pray for my soul as I go back into the dark....

UPDATE: Okay, so I'm closer to a solution. The results I'm getting are consistently about 60-90 wave numbers too low from what they should be. Now to figure out just where this error is coming from, and back into the abyss (I like that word, it just looks ominous and full of foreboding, I don't really remember much about the movie other than I confused it with Cocoon until I was about 17 years old, hmm, maybe it wasn't that good of a movie after all)  once again...

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