ular style
the constraint itself must first be defined by a 
  &quot;fix style&quot; command
multiple groups of atoms or bond types can be assigned to the same constraint
the bondtype option can only be assigned to a "fix style" of "shake",
  multiple bondtypes can be SHAKEn, so long as the size of clusters of
  atoms does not exceed the limit described in the "fix style" command
the angletype option can only be assigned to a "fix style" of "shake",
  only a single angletype can be SHAKEn, it is designed to