In contrast to ITo a multitude of non-systematic extinctions among the first lines may not appreciably affect the power of trial-and-error methods. However, powder indexing is not like structure analysis, which works well on good data, and will usually get by on poor data given a little more time and attention. Powder indexing works beautifully on good data, but with poor data it will usually not work at all. ' (op cit Ref. 4D 苏五长 有一太苏 玉 长 In contrast to ITO a multitude of non-systematic extinctions among the first lines may not appreciably affect the power of trial-and-error methods. However, 'powder indexing is not like structure analysis, which works well on good data, and will usually get by on poor data given a little more time and attention. Powder indexing works beautifully on good data, but with poor data it will usually not work at all.' (op.cit Ref.[4])