Comprehensive computational experiments were performed to evaluate efficiency of the newly proposed procedure on protein structure calculations from NMR data. This procedure is intended to combine merits of the previously developed method with the program, widely used for NMR structure calculations. The new version of the program, , was developed to determine local conformations of proteins consistent with short-range NMR data (intraresidue and sequential distance constraints and coupling constants). For each residue, the program determines the allowed ranges of φ, ψ and χ₁ torsion angles consistent with the NMR data. The benchmark calculations were carried out on three proteins: bovine pancreatic trypsin inhibitor, crambin and avian pancreatic polypeptide. The results of the calculations obtained by the protocol were compared with the results obtained by the run of the program. The procedure allowed one to significantly narrow ranges of the dihedral angle constraints before the structure calculations that, in turn, resulted in more stereospecific assignments. The numbers of βCH₂ groups unambiguously assigned using the procedure were significantly greater in comparison with those assigned by the protocol. For all three proteins, the use of the procedure almost doubled the numbers of unambiguously assigned βCH₂ groups in comparison with . The computational experiments clearly showed that the use of allowed ranges for torsion angles obtained by the procedure as input data for the program provides a higher precision and accuracy of 3D protein structures reproduced from NMR constraints. The procedure may be incorporated into any protocol using as input data the allowed ranges of torsion angles consistent with a given set of NMR constraints. Since the procedure proved to be effective, reliable and robust, it may be recommended for general use in 3D structure determination of proteins and peptides from NMR data.