The write structure statement writes the current molecular
structure to the specified
output file. The molecular
structure file (which for historical reasons is sometimes
called a PSF---protein
structure file) contains information that was generated by the
segment statement and modified by the patch statement or the
delete statement. Specifically, the molecular
structure file contains the following
information: atom names, types, charges, and masses; residue names and segment
names; and a list of bond terms, angle terms, dihedral terms, improper terms,
explicit hydrogen-bonding terms, explicit nonbonded exclusions, and nonbonded
group partitions. It does not contain atomic coordinates,
parameters, constraints, restraints,
or any other information that is
specific to effective energy terms, such as diffraction data.