PSF 3 !NTITLE REMARKS original generated structure x-plor psf file REMARKS topology HE.top REMARKS segment G { first NONE; last NONE; auto angles dihedrals } 1 !NATOM 1 G 0 HH HEL HE 0.000000 2.0160 0 0 !NBOND: bonds 0 !NTHETA: angles 0 !NPHI: dihedrals 0 !NIMPHI: impropers 0 !NDON: donors 0 !NACC: acceptors 0 !NNB 0 1 0 !NGRP 0 0 0