sub coordinatesorter {

local (*Axcoord, *Aycoord, *Azcoord, *Bxcoord, *Bycoord, *Bzcoord, *res_to_atom, *natres, $nseg, *beginning, *ending) = @_;

my @Axcord;
my @Aycord;
my @Azcord;
my @Bxcord;
my @Bycord;
my @Bzcord;
my $interdomaincounter=1;
my $counter = 0;

for ($iseg = 1; $iseg <= $nseg; ++$iseg){

  for ($ires = $beginning[$iseg]; $ires <= $ending[$iseg]; ++$ires) {

	        	for ($iat = 1; $iat <= $natres[$ires]; ++$iat) {

		$Axcord[$counter] = $Axcoord[$res_to_atom[$ires][$iat]];
		$Aycord[$counter] = $Aycoord[$res_to_atom[$ires][$iat]];
		$Azcord[$counter] = $Azcoord[$res_to_atom[$ires][$iat]];
		$Bxcord[$counter] = $Bxcoord[$res_to_atom[$ires][$iat]];
		$Bycord[$counter] = $Bycoord[$res_to_atom[$ires][$iat]];
		$Bzcord[$counter] = $Bzcoord[$res_to_atom[$ires][$iat]];

		$counter++;

		}
	}
}

return (\@Axcord, \@Aycord, \@Azcord, \@Bxcord, \@Bycord, \@Bzcord);

}