Self-Assessment: Crystalline Materials Weekly Homework Quiz Calculate the acceleration potential that will result in electron diffraction from the (311) plane of platinum (Pt) at an angle, θ, of 33.3°. The lattice constant of platinum, a, has a value of 3.92 Å. MIT OpenCourseWare http://ocw.mit.edu 3.091SC Introduction to Solid State Chemistry Fall 2009 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms.