low pressure fails in fix gcmc

hi,
thanks for your reply.
the option full_energy is default in the last version of lammps.
with a combination of NVT and GCMC. the temperature is stable. I noticed that with little volume the insert of argon is more simple.

the pressure is still too low compared to what I ask in fix gcmc 0.9
how can I do it?

step Volume Temp Press Atoms v_mol v_V0L v
_T v_mol_L v_P1_eff
0 1000000 87 0.10
66795 10 1.6605389e-23 1e-21
87 0.016605389 0.12011641
1000 1000000 86.940634 0.0682
22571 87 1.4446688e-22 1e-21
86.940634 0.016605389 0.12003444
2000 1000000 87 0.0651
05959 90 1.494485e-22 1e-21
87 0.016605389 0.12011641
3000 1000000 86.900727 -0.051224566 90 1.494485e-22 1e-21 86.900727 0.016605389 0.11997935