ABSTRACT
We describe an algorithm for rotational motion in molecular dynamics simulations. The algorithm requires neither quaternions nor Euler angles and works by updating the local Cartesian axes of the rotating body, the components of which also provide the rotation matrix.
Disclosure statement
No potential conflict of interest was reported by the author(s).
Notes
1 The principal frame differs from the local frame in that the latter is rotating with the molecule while the former is stationary. They happen to coincide at the instant equation (28) holds.