The 
values (cf. Eqs. 4.8 and 4.10)
in the parameter file ``parallhdg.pro"
are different from those used in the other all-hydrogen
force fields. The changes were made to make the van der Waals radii
more consistent with those used by other
NMR refinement programs.
The 
values have been
set such that the van der Waals
radii will be exactly like those used by the DISGEO program
(Havel and Wüthrich 1984) when
REPEl (Section 3.2.1) is set to 0.8.
In addition, van der Waals radii
of potential hydrogen bond donor--acceptor
pairs have been reduced
by appropriate NBFIx statements.
The actual van der Waals
radii used for different values of REPEl are given in the
table below (in Å).
It should be noted that the van der Waals radii in ``parallhdg.pro" are not appropriate with the standard Lennard-Jones potential (Eq. 4.8).