The first step in analysing unknown powder pattern is often an attempt to find a unit cell that explains all observed lines in the spectrum You do not need additional crystallographic data, although if it exists it makes for faster and more reliable results The material to be analysed must be single phased and the experimental material must be very accurate 苏五长 有一太苏 玉 长 The first step in analysing unknown powder pattern is often an attempt to find a unit cell that explains all observed lines in the spectrum. You do not need additional crystallographic data, although if it exists it makes for faster and more reliable results. The material to be analysed must be single phased and the experimental material must be very accurate