Generate a well-defined PTRAC file for PyNE test cases
c -- cell cards
1   0   -1:2:-3:4:-5:6    imp:n=0     $ out of world
2   0    1 -2 3 -4 5 -6   imp:n=1     $ vacuum cube

c -- surface cards
1   px      -5.0
2   px       5.0
3   py      -5.0
4   py       5.0
5   pz      -5.0
6   pz       5.0

c -- data cards
mode n
nps 5
sdef
dbcn 1 $ fixed seed
ptrac file=bin
