Document for fitfc and fitsvsl

Hi Everyone,

I am trying to understand how full force constant matrix is transferred to stretching-bending spring model and how vibrational entropy is calculated from those stretching and bending terms. Is there any document explaining this procedure with examples and equations?

Best Regards
Anus Manzoor
Graduate Student
USA

These might help:
https://dx.doi.org/10.1103/PhysRevB.61.5972
https://dx.doi.org/10.1103/RevModPhys.74.11
and of course
svsl -h
fitsvsl -h