Print improper info for selected atoms.

improperinfo [parm <name> | parmindex <#> | <#>] [<mask1>] [<mask2> <mask3> <mask4>] [out <file>]

[parm <name> | parmindex <#> | <#>] Name/tag or index of topology. Default is first loaded topology.
[<mask1>] Mask to print improper info for.
[<mask2> <mask3> <mask4>] If specified, impropers must match all masks.
[out <le>] File to print to (default STDOUT).

For specified topology (rst by default) either print CHARMM improper info for all atoms in <mask1>, or print info for dihedrals with rst atom in <mask1>, second atom in <mask2>, third atom in <mask3>, and fourth atom in<mask4>.