CCL:Re: Molecular alignment

[petitjean-0at0-itodys.jussieu.fr]

To: CHEMISTRY-0at0-ccl.net
 Subject: CCL:Re: Molecular alignment
 A traditional non parametric method is used by CSR: goto
 http://petitjeanmichel.free.fr/itoweb.petitjean.freeware.html#CSR
 and look at the reference in the documentation.
 Since it is a purely geometric method, the mean points of the
 common 3D motifs are aligned (but NOT those of the whole molecules).
 This is a consequence of the optimality of the translation,
 for the rms criterion, applied to the pair of common 3D motifs.
 Michel Petitjean,                     Email: petitjean-0at0-itodys.jussieu.fr
 ITODYS (CNRS, UMR 7086)                      ptitjean-0at0-ccr.jussieu.fr
 http://petitjeanmichel.free.fr/itoweb.petitjean.html
 >Dear,
 >
 >I am developing a new technique for molecular alignment, based on quantum
 >chemistry. I would like to know more about the more traditional methods to
 >produce the translation and rotation of molecules as a whole. More
 >precisely, I am looking for methods that do NOT
 >- involve Euler's angles (parameters)
 >- depend on first aligning mass centres.
 >
 >Surely, there must have been published some other affine techniques, and
 >you would help a lot if you could point in some good direction !
 >
 >Thanks,
 >
 >Patrick Bultinck
 >Ghent Quantum Chemistry Group
 >Ghent University
 >Belgium