SpectraFit: a new program to simulate and fit distributed B-10 powder patterns - application to symmetric trigonal borons

We have developed a new program in C++ to simulate B-10 NMR powder patterns. The program takes into account the quadrupolar interaction of B-10 (1=3) and it allows for the use of a Gaussian distribution of the quadrupolar interaction parameters to fit solid amorphous and crystalline materials. A key aspect of this program is that it has been automated to find the best-fit parameters of the quadrupole coupling constant (C-Q) and the asymmetry parameter (eta) as well as the widths (sigma(CQ) and sigma(eta)) of their distributions. Initially, this program has been extensively used, with the aid of the earlier and non-automatic QuadFit developed by Tom Kemp at the University of Warwick (UK), to find the best fit parameters of B-10 NMR spectra in amorphous B2O3 prepared at different cooling rates as well as polycrystalline lithium ortho borate, Li3BO3. The technique is sensitive enough to clearly see differences in the three-coordinated boron quadrupole parameters.