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Files “topnah1e.dna" and “parnah1e.dna" for Nucleic Acids
(Explicit All Hydrogens)
This force field, by Nilsson and Karplus (1986),
treats all hydrogens explicitly.
The force field uses an explicit hydrogen bonded potential.
For crystallographic refinement, it is generally necessary to
restrain the sugar pucker by using the restraints dihedral
statement (see Section 7.2). Furthermore,
it may be necessary to increase the energy constants of the
improper angles to ensure planarity of the bases.