STOCKHOLM (AP) -- Israeli scientist Daniel Shechtman won the 2011 Nobel Prize in chemistry on Wednesday for his discovery of quasicrystals, a chemical structure that researchers previously thought was impossible.

The Royal Swedish Academy of Sciences said Shechtman's discovery in 1982 fundamentally changed the way chemists look at solid matter.

Contrary to the previous belief that atoms were packed inside crystals in symmetrical patterns, Shechtman showed that the atoms in a crystal could be packed in a pattern that could not be repeated, the academy said.

The academy said his finding was so controversial that he was asked to leave his research group.

But since then, quasicrystals have been produced in laboratories and a Swedish company found them in one of the most durable kinds of steel, which is now used in products such as razor blades and thin needles made specifically for eye surgery, the citation said.

They were discovered in nature for the first time in 2009, according to the citation.

``His battle eventually forced scientists to reconsider their conception of the very nature of matter,'' the academy said.

``It feels wonderful,'' Shechtman, a distinguished professor at the Israel Institute of Technology in Haifa, told The Associated Press.

The Nobel Prize in chemistry announcement capped this year's science awards.

Immune system researchers Bruce Beutler of the U.S. and Frenchman Jules Hoffmann shared the medicine prize Monday with Canadian-born Ralph Steinman, who died three days before the announcement. U.S.-born scientists Saul Perlmutter, Brian Schmidt and Adam Riess won the physics prize on Tuesday for discovering that the universe is expanding at an accelerating pace.

The 10 million kronor ($1.5 million) Nobel Prizes are handed out every year on Dec. 10, the anniversary of award founder Alfred Nobel's death in 1896.