I. INTRODUCTION. Conformational changes of macromolecules are essential in the understanding of e.g. proteins and drug design. The theoretical prediction is far from trivial, especially for large molecules. In many cases, collective motions are present which occur on a timescale (~ms) that is too long to be accessible through molecular dynamics simulations. Normal mode analysis (NMA) has been proven succesful in exploring the potential energy surface (PES) within the harmonic oscillator approximation.
The lowest frequency modes contribute the most to a conformational change. This paper presents a computationally attractive method that selects modes from the lower spectrum
