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.