set lipid [atomselect top "resname $lipres"];
set lipidbox [measure minmax $lipid];
set xmin [lindex [lindex $lipidbox 0] 0];
set xmax [lindex [lindex $lipidbox 1] 0];
set ymin [lindex [lindex $lipidbox 0] 1];
set ymax [lindex [lindex $lipidbox 1] 1];
set zmin [lindex [lindex $lipidbox 0] 2];
set zmax [lindex [lindex $lipidbox 1] 2];
set selA [atomselect top "same residue as water and z>$zmin and z<$zmax"] set selB [atomselect top "all not {same residue as water and z>$zmin and z<$zmax}"] puts "all not {same residue as water and z>$zmin and z<$zmax}"
set rmwatlen [llength [$selA get resid]];
set rmwatnum [expr $rmwatlen/3];
puts "remove water atom is $rmwatlen, and molecular is $rmwatnum"
$selB writepdb rmfinal.pdb
set all [atomselect top water]
set allwat [expr [llength [$all get resid]]/3];
set rmwatnum [expr $allwat-$rmwatnum];
puts "Original water molecules number is $allwat"
puts "Water molecules left $rmwatnum";
$lipres替换成你要的磷脂resname