An Electronic Computer for X‐Ray Crystal Structure Analyses

An electronic synthesizer is described for determination of atomic positions in crystals. The synthesizer sums the two‐dimensional Fourier series representing planar, centro‐symmetric projections of electron densities in a crystal unit cell; and the projection is presented by a television scan on the screen of a cathode ray oscilloscope. The specific advantage of the device is the immediate observability of effects on the projection of alterations in signs of one or any number of Fourier coefficients.