Three US-based scientists have won this year's Nobel Prize in chemistry for developing powerful computer models that any researcher can use to understand complex chemical interactions and create new drugs.

Research in the 1970s by Martin Karplus, Michael Levitt and Arieh Warshel has led to programmes that unveil chemical processes such as how exhaust fumes are purified or how photosynthesis takes place in green leaves, the Royal Swedish Academy of Sciences said on Wednesday.

That kind of knowledge makes it possible to optimize catalysts for cars or design drugs and solar cells. The strength of the winning work is that it can be used to study all kinds of chemistry, the academy said.

"This year's prize is about taking the chemical experiment to cyberspace," said Staffan Normark, the academy's secretary.

Karplus, an 83-year-old US and Austrian citizen, splits his time between the University of Strasbourg, France, and Harvard University.

The academy said Levitt, 66, is a British, US, and Israeli citizen and a professor at Stanford University School of Medicine. Warshel, 72, is a US and Israeli citizen affiliated with the University of Southern California in Los Angeles.

"In short, what we developed is a way which requires computers to look, to take the structure of the protein and then to eventually understand how exactly it does what it does,'' Warshel said.

'A gate between two worlds'

When scientists wanted to simulate complex chemical processes on computers, they used to have to choose between software that was based on quantum physics, which applies on the scale of an atom, or classical Newtonian physics, which operates at larger scales.

The academy said the three laureates developed computer models that "opened a gate between these two worlds".

While quantum mechanics is more accurate, it's impossible to use on large molecules because the equations are too complex to solve. By using quantum mechanics only for key parts of molecules and classical physics for the rest,
the blended approach delivers the accuracy of the quantum approach with manageable computations.

The Nobel Literature Prize will be announced on Thursday, the Nobel Peace Prize on Friday and the economics prize on Monday.

Source: Agencies