Hi all,
I have a trouble to start a simulation with fix npt and fix wall/lj126. System contains dendrimer, Na & Cl atoms,1200 H2O molecules (TIP3P) and input looks like this :
echo log
log den_eq.4.log
dimension 3
units metal
boundary p p p
timestep 0.001500
atom_style full
read_data data.den_eq.4
group aaa type 1 2 3 4 5 6
group bbb type 7 8 9 10 11 12 13 14
group ccc type 15 16 17 18 19
group Na type 20
group Cl type 21
group H2O type 22 23
group dendrymer union aaa bbb ccc
fix bal all balance 10000 xyz 20 1.1
pair_style lj/cut/coul/long 12.000000
pair_coeff 1 1 0.004743 3.399670 #c3_a-c3_a
…
kspace_style ewald 1.0e-4
bond_style harmonic
bond_coeff 1 29.127733 1.093000
…
angle_style harmonic
angle_coeff 1 4.020141 110.070000
…
dihedral_style multi/harmonic
dihedral_coeff 1 0.054631 0.039022 -0.041624 -0.052030 0.000000
…
variable zllo equal zlo
variable zhhi equal zhi
variable Etot equal etotal
fix wallo all wall/lj126 zlo v_zllo 0.3 1. 5. units box pbc yes
fix walhi all wall/lj126 zhi v_zhhi 0.3 1. 5. units box pbc yes
thermo_style custom temp press pe lx ly lz
thermo 500
fix shake H2O shake 0.0001 20 0 b 11 a 20
fix fxnpt all npt temp 310.0 310.0 0.1 iso 1. 1. 1.
dump xyz all xyz 20 den_eq.4.xyz
fix tave all ave/time 2 1 2 c_thermo_temp c_thermo_pe c_thermo_press v_Etot file den_eq.4.avs
run 2000
write_restart den_eq.4.restart
and I get
Temp Press PotEng Lx Ly Lz
0 -425.41473 113.93615 100 100 200
470.54449 -282.16068 -6039.3123 91.885824 91.885824 183.77165
324.48267 -241.03243 -7798.1488 85.942783 85.942783 171.88557
-nan -nan -nan -nan -nan -nan
-nan -nan -nan -nan -nan -nan
Loop time of 403.871 on 32 procs for 2000 steps with 42164 atoms
When fix wall is off everything is ok.
any suggestions why fix wall is not working here?