*  The interatomic data container now has the dipole_pair flag initialised to False.
*  Expanded the return_interatom() function to handle a single spin ID.  This function now returns a list of matching interatomic data containers.
*  Modified the check_args() method of the dauvergne_protocol model-free auto-analysis [d'Auvergne and Gooley, 2007][d'Auvergne and Gooley, 2008] for the new data.  The heteronuc_type and proton_type are now in the spin's isotope variable, and the bond length 'r' is now the interatomic distance variable 'r'.  All spin containers and interatomic data containers are being checked.
*  Expanded the RelaxNoValueError to handle one or two spin IDs as arguments.  This is to better identify which spins or interatomic data containers are deficient.
*  The nuclear isotope is now defined via spin.isotope.
{{:relax release announcements}}
 
= References =
 
<section start=references/>
* [*d'Auvergne and Gooley, 2007] d'Auvergne, E. J. and Gooley, P. R. (2007).  Set theory formulation of the model-free problem and the diffusion seeded model-free paradigm.  ''Mol. BioSyst.'', '''3'''(7), 483–494. (DOI: [http://dx.doi.org/10.1039/b702202f 10.1039/b702202f).
* [*d'Auvergne and Gooley, 2008] d'Auvergne, E. J. and Gooley, P. R. (2008).  Optimisation of NMR dynamic models II.  A new methodology for the dual optimisation of the model-free parameters and the Brownian rotational diffusion tensor.  ''J. Biomol. NMR'', '''40'''(2), 121-133. (DOI: [http://dx.doi.org/10.1007/s10858-007-9213-3 10.1007/s10858-007-9213-3]).
<section end=references/>
<HarvardReferences />
= See also =
{{:relax release see also}}