Ab initio structure solution by charge flipping. II. Use of weak reflections

摘要: The original charge flipping algorithm [Oszlanyi & Sutő (2004). Acta Cryst. A60, 34–141] is an amazingly simple structure solution method which works ab initio on high-resolution X-ray diffraction data. In this paper, a new version of the presented that complements phase exploration in reciprocal space. Instead prescribing observed moduli all factors, weak reflections are treated separately. For these reflections, calculated accepted unchanged and phases shifted by constant Δφ = π/2. This means data not used iteration, except for knowledge they indeed weak. improvement drastic, some cases success rate increased factor ten, other previously unsolvable becomes solvable modified algorithm.