(gdb) run tmp.dat 0.1
Starting program: /home/dli/ad/g073/z1pt tmp.dat 0.1
Using checkpoint file tmp.dat.chkpt
Simulating box: number of particles= 2016 (41.5692,42), sigma= 1
Potential cutoff rv= 1.5
T= 0.1
dl100= 1.16415e-12
terminate called after throwing an instance of 'std::out_of_range'
  what():  vector::_M_range_check

Program received signal SIGABRT, Aborted.
0xffffe410 in __kernel_vsyscall ()
(gdb) help backtrace
Print backtrace of all stack frames, or innermost COUNT frames.
With a negative argument, print outermost -COUNT frames.
Use of the 'full' qualifier also prints the values of the local variables.

(gdb) backtrace full
#0  0xffffe410 in __kernel_vsyscall ()
No symbol table info available.
#1  0xb7cb8bf7 in raise () from /lib/libc.so.6
No symbol table info available.
#2  0xb7cba120 in abort () from /lib/libc.so.6
No symbol table info available.
#3  0x00000000 in ?? ()
No symbol table info available.
(gdb)