musings on music and life

October 17, 2013

Congrats Prof. Warshel!

Filed under: Chemistry — Tags: — sankirnam @ 7:41 pm

It’s been a crazy week here so far. It was just last Wednesday that I heard the news about this year’s Nobel Prize in Chemistry. I woke up at 4 AM that morning and checked the website out of curiosity and was pleasantly surprised to see Prof. Warshel’s name among the recipients! I had the opportunity to TA for him during my first and second years, which proved to be a very interesting experience. Warshel, along with Karplus and Levitt, received the 2013 Nobel prize in Chemistry “for the development of multiscale models for complex chemical systems”. Warshel was a postdoc with Karplus, and with Levitt, co-developed their hybrid QM/MM (quantum mechanical/molecular mechanical) method for simulations of extremely large molecules. This method soon became extremely popular for simulating enzymatic reactions and doing calculations on extremely large molecules, such as proteins.

The last time a Nobel Prize in chemistry was awarded for computational work was in 1998, to Pople and Kohn for developments in DFT (density functional theory) and developments of methods for doing quantum chemical calculations. Their work was extremely important; Pople’s work led to the founding of the company Gaussian (from which he was subsequently banned) and the popular eponymous software package. Kohn’s work in DFT laid the foundation for Axel Becke’s development of the hybrid method B3LYP, which is used by thousands of scientists worldwide every day. In short, the work of Pople and Kohn enabled quantum chemical calculations to be carried out on computers. As computer power increased over the decades, higher levels of theory and larger orbital basis sets could be employed on increasingly bigger molecules to greater levels of precision. However, quantum calculations are limited to small molecules. Doing a purely quantum calculation on a very large molecule, such as a protein, is computationally prohibitive.

By combining quantum mechanics with molecular mechanics (which is greatly simplified and simply views bonds as masses on springs, a la classical mechanics), Warshel, Karplus, and Levitt greatly simplified the calculation of very large systems. The difficult part is finding out which approximations are appropriate and making tradeoffs for time vs. accuracy.

We had 2 parties sponsored by the Chemistry department and the Dean last week, upon hearing the news!


I also attended a press conference hosted by the President of USC, Max Nikias, earlier that morning:

Hopefully this should increase USC’s reputation as a research university in the years to come…


October 7, 2013

2013 Nobel prize in chemistry picks

Filed under: Chemistry — Tags: , — sankirnam @ 11:06 pm

My picks for this year are the same as those I had last year. Not much to say here…

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