The 2013 “Postgraduate Magnetic Techniques Workshop” organised by the Insitute of Physics is taking place today. It is a workshop to provide introductory training in key experimental and theoretical techniques used in magnetic research, aimed at new postgraduate students and research fellows new to magnetic research. My talk will be on the atomistic spin dynamics model and how it can be used to describe magnetization dynamics in the femtosecond regime. I will focus on how the model is constructed and how it is being used to compare to experimental observations. The talk will be available on the conference presentations page.