Lattice constant at different temperature

I want to calculate the lattice constant at different temperature. The temperature increases then decreases and does not reach the requested value, I do not know when I will stop my simulation
Any Help!
units metal
dimension 3
boundary p p p
atom_style atomic
read_data sd
#group delete id 647
#delete_atoms group delete

pair_style polymorphic
pair_coeff * * InGaN_sw.poly N Ga In

#pair_style sw
#pair_coeff * * GaN.sw Ga N

neighbor 2.0 bin
neigh_modify delay 10 check yes

timestep 0.000001
compute new all temp

velocity all create 0.01 12345 temp new
#fix F1 all box/relax iso 0 vmax 0.01 fixedpoint 0 0 0
fix 1 all npt temp 500 500 0.1 iso 0.0 0.0 1

thermo 100
thermo_style custom step ke etotal temp vol lx ly lz

dump MyDump all custom 250 dump.atoms id type x y z vx vy vz fx fy fz

#min_style cg
#minimize 1.0e-10 1.0e-10 5000 10000
restart 80000 file.restart
run 1000000
sd (25.7 KB)

This is a question about basic MD processes and how to understand and execute them correctly.
This has thus nothing to do with LAMMPS (you just happen to use LAMMPS) and thus is something you should discuss with the people advising and tutoring you. Multiple settings in your input make little sense for the purpose you are describing and the commented out commands are quite distracting, too.