[Wien] error in 2X2X2 supercel MgO following guide

[夏宇阳]

Dear all, 
When i follow the latest guide to make a supercell for MgO, an error came out.
i mark the first Mg as Mg1.And then i face an error when i do x nn.

Fortran runtime error: Bad value during integer read

Error termination. Backtrace:
#0  0xb3c5d623960 in ???
#1  0xb3c5d6244d9 in ???
#2  0xb3c5d62510f in ???
#3  0xb3c5d8753a7 in ???
#4  0xb3c5d879ae5 in ???
#5  0xb3c5d87ae55 in ???
#6  0x583a57ce8bad in ???
#7  0x583a57ce726e in ???
#8  0xb3c5d229d8f in __libc_start_call_main
	at ../sysdeps/nptl/libc_start_call_main.h:58
#9  0xb3c5d229e3f in __libc_start_main_impl
	at ../csu/libc-start.c:392
#10  0x583a57ce7294 in ???
#11  0xffffffffffffffff in ???

Also, i cant use xcrysden to view the struct and setrmt for it.

How can i fix it?

Looking forward to your reply.

With regards!