(gdb) b MD.o.c:649 <-- Calc_gr (gdb) b MD.o.c:671 <-- Calc_vacf (gdb) r Breakpoint 1, Calc_gr (particle=0x827dea0) at MD.o.c:649 (gdb) c 649 fclose(file_gr); (gdb) p &j $1 = (int *) 0xffffc168 (gdb) p j $3 = 144 (gdb) c Breakpoint 2, Calc_vacf () at MD.o.c:671 671 vacf[j-i]=0; (gdb) p &j $6 = (int *) 0xffffc168 (gdb) p j $7 = 144