Syntax BREAK BOND atom-num atom-num
RESIDUE atom-num atom-num
SEGMENT atom-num atom-num
BREAK BOND breaks a covalent bond between the two specified atoms. BREAK RESIDUE breaks a residue in 2 parts after the first specified atom BREAK SEGMENT breaks a segment in 2 parts between the two atoms. Different residues or segments can not be broken. 2 atom-numbers should be defined properly to avoid making non-sense.