The movement of electron density is a subject of interest for chemists worldwide, as substances interact through electrons. These processes are ultrafast and traditionally require time-resolved experiments at the attosecond level to study and describe. However, there are alternative methods. The movement of electron density is a subject of interest for chemists worldwide, as substances interact through electrons. These processes are ultrafast and traditionally require time-resolved experiments at the attosecond level to study and describe. However, there are alternative methods. Analytical Chemistry Phys.org – latest science and technology news stories