A CRYSTALLOGRAPHIC LEAST SQUARES REFINEMENT PROGRAM FOR THE IBM 704: IDENTIFICATION PS XR3,
Abstract
The crystallographic least-squares program PS XR3 (Penn State X-Ray Program 3) is applied to an iterative procedure which adjusts unknown param eters-which are in this case the atomic co ordinates x sub i, Y sub i, Z sub i of a given crystal structure and the isotropic temperature factor B sub i of individual atoms-until the calculated structure factors F calc show the best agreement with the observed structure factors F obs. This is achieved by using the so called diagonal approximation of the least squares method. Since the crystal structure equations are highly non-linear, only the first linear terms of the Taylor expansion are used, and the initial solution must be approximately known and supplied to the computer via the so called co-ordinate deck read with the program. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1959
- Accession Number
- AD0418723
Entities
People
- R. Pepinsky
- V. Vand
Organizations
- Pennsylvania State University