Rmat3 will build on the progress made in variational calculations of molecular spectra by using these methods to provide rovibrational wavefunctions for the whole system at short internuclear distances
Halogen bonding reduces internuclear distances
up to twenty percent as compared to the all Van der waals distances .
That condition in no way precludes a useful, and generally moderately accurate, calculation of conformations, and their internuclear distances
and angles, in molecules and their aggregates with programs for molecular electronic structure, based on and requiring an empirical separation of electronic and nuclear motions, just as one might apply for the same purpose methods of molecular mechanics  that might have no quantum-mechanical component or justification whatsoever.
ii) the homo- and heteronuclear dipolar interactions, which are spatial in nature and related to the internuclear distances.
7) (iii) measurement of internuclear distances by solid-state NMR can be achieved.
The derived molecular properties, such as rotational and centrifugal distortion constants, hyperfine structure constants, electric dipole moments, rotational g-factors and internuclear distances
(for diatomic molecules) are listed with one standard deviation uncertainties for all species.