THEORY OF ATOMIC STRUCTURES

Press, Volume XCIII, Issue 27989, 8 June 1956, Page 13

THEORY OF ATOMIC STRUCTURES

RESEARCH WITH AID OF X-RAYS

•X-ray structural work had. during the last 40 years, greatlv extended the knowledge and understanding of the nature of the forces which operated between atoms and within and between molecules in solids, said the rector of Canterbury University College (Dr. F. J. Llewellyn), in an address to the mathematics and physics sections of the Canterbury branch of the Royal Society of New Zealand last evening. Much of the early work was concerned with determining the relative positions of atoms, their size and the distances between them, he said. Particularly in the case of simple salts such as sodium chloride ana in the minerals, very important generalisations had been made possible. “More recently, the chemical structures of such substances as penicillin and strychnine have been elucidated by these methods.” Dr. Llewellyn said. “For many years they baffled the organic chemist. The techniques and the accuracy of the results are now such that it is possible to check theoretical calculations involving the disposition of the electrons which are concerned with holding molecules together. “There is scarcely an field of scientific ' endeavour which has not benefited. either directly or indirectly, from the efforts of the - X-ray crystallographer to unravel the nature of the •solid state.” said Dr. Llewellyn.