I have molecule coordinates in body-frame and in space-frame, but i need calculate the quaternions that related both systems, how do you get the queternions?

-- Florianne Castillo (fcast@avantel.net), August 01, 2003

Answers

Hello Florianne:

There is no universally agreed on way to define a body-frame or space-frame. It is rare to find two books that define Euler angles the same way.

There is a good paper on the topic of swtiching between 3D systems and quaternions available at my web site. The paper requires a careful read, but it should address the question.

doug

http://world.std.com/%7Esweetser/quaternions/ps/stanfordaiwp79-salamin.ps.gz

-- Douglas Sweetser (sweetser@alum.mit.edu), August 03, 2003.