Her role was to help with the computing for the crystallographers. There are several standard notations used by crystallographers, mineralogists, and physicists. Many crystallographers and modellers spent arduous months trying to fit such activities into this architecture. Crystallographers classify twinned crystals by a number of twin laws. Crystallographers make use of linear algebra by using the Metrical Matrix. Crystallographers also use the Free R-Factor (formula 5) to assess possible overmodeling of the data.