writeBmat package

This package contains tools for generating internal coordiantes and the corresponding B matrix [1] for molecules as well as for periodic systems. It is a part of of the GADGET suite and if you use writeBmat in a scientific publication, please cite it as:

Bučko, T., Hafner, J., & Ángyán, J. G. (2005). Geometry optimization of periodic systems using internal coordinates. The Journal of Chemical Physics, 122(12), 124508. doi:10.1063/1.1864932
[1]Wilson, E. B., Decius, J. C., & Cross, P. C. (1955). Molecular Vibrations: The Theory of Infrared and Raman Vibrational Spectra. book, Dover Publications.