LSRES provides for the creation or modification of the logical records lrbond: (distance restraints), lrangl: (bond angle restraints), lrdihe: (dihedral angle restraints) and lrrigi: (rigid bond restraints). The atoms must be on the input bdf, and for each rigid bond restraint, at least one atomic displacement factor must be anisotropic, and neither may be overall. All restraints that are output on the archive bdf are computed and tested to make sure two atoms do not occupy the same position.

LSRES accepts restraints between symmetry-equivalent atoms as defined by symeq line. Introduction of atoms outside the unit cell is achieved by translations greater than 1.

In update mode, when an atom name is used it is taken to apply to all symmetry-equivalent atoms based on the named atom, whereas a symmetry-equivalent atom name applies only to the atom generated by the particular symmetry operation. This means that if the user gives atom names instead of symmetry-equivalent names, LSRES will select the first matching restraint ( restr line) or all matching restraints ( delres line). Besides, for the delres line only, the "wild field" all is for any atom in any symmetry-equivalent position. For example:

This can be useful to delete bond angle and dihedral angle restraints.

LSRES  apr
restr  dist  C31   C71   1.458   0.0001
restr  bond  C31   C71   0       0.0001
restr  dist  C32   C72   1.458   0.0001
restr  bond  C32   C72   0       0.0001

Introduction of 4 restraints, 2 bond distances, and 2 rigid links.

LSRES  upd
symeq  C32  C325    -z  -x  -y
symeq  C72  C725    -z  -x  -y
delres dist
delres bond C71
restr  bond C32   C325   0        0.0001
restr  bond C72   C725   0        0.0001

Creates symmetry-equivalent atoms to C32 & C72, delete all distances restraints, delete all rigid bond restraints on atom C71 and all its symmetry-equivalent atoms, and insert restraints between C32 and a symmetry-equivalent atom, and C72 and a symmetry-equivalent atom.