From the Bax Group at the National Institutes of Health ...
SPARTA+ Server:
Improved Prediction of Protein Backbone Chemical Shifts from Structure
As described in the paper:
SPARTA+: a modest improvement in
empirical NMR chemical shift prediction by means of
an artificial neural network. Yang Shen and Ad Bax.
J. Biomol. NMR, 48, 13-22 (2010).