• By accurately measuring peak positions over a long range of 2θ, you can determine the unit cell lattice parameters of the phases in your sample

–alloying, substitutional doping, temperature and pressure, etc can create changes in lattice parameters that you may want to quantify

–use many peaks over a long range of 2θ so that you can identify and correct for systematic errors such as specimen displacement and zero shift

–measure peak positions with a peak search algorithm or profile fitting

• profile fitting is more accurate but more time consuming

–then numerically refine the lattice parameters