Hello everyone,
I am calculating stress for tobermorite crystal. I am applying uniaxial deformation using fix deform command. The potential parameters I am using are CSHFF potential. But, instead of fracturing at some strain, the stress kept on increasing which is not physical. What can be wrong in my code? Here it is:
Regards,
Baig
Tobermorite-14A
Uniaxial strain in x-direction (zigzag)
Initialization
echo screen
log debug_14t.log
units real
atom_style full
boundary p p p
Bonded Interaction
bond_style morse
angle_style harmonic
dihedral_style harmonic
improper_style cvff
Non-Bonded Interaction
pair_style lj/cut/coul/long 10.0 10.0 # cutoff1 = 2.5*sigma
read_data data.14tcsh
kspace_style ewald 1e-6
pair_coeff 1 2 0.0087 3.7064
pair_coeff 1 3 0.000884 4.898
pair_coeff 1 4 0.000884 4.898
pair_coeff 1 5 0.0146 4.898
pair_coeff 1 6 0.00877 4.898
pair_coeff 1 7 0.0 3.12
pair_coeff 1 8 0.0 3.12
pair_coeff 2 3 0.00561 3.6716
pair_coeff 2 4 0.00561 3.6716
pair_coeff 2 5 0.00595 3.6627
pair_coeff 2 6 0.00530 3.6298
pair_coeff 2 7 0.0 1.8532
pair_coeff 2 8 0.0 1.8532
pair_coeff 3 4 1.2433 3.0687
pair_coeff 3 5 0.0455 4.0654
pair_coeff 3 6 0.00525 4.7557
pair_coeff 3 7 0.0 1.7766
pair_coeff 3 8 0.0 1.7766
pair_coeff 4 5 0.0455 4.0654
pair_coeff 4 6 0.0455 4.0654
pair_coeff 4 7 0.0 1.7766
pair_coeff 4 8 0.0 1.7766
pair_coeff 5 6 0.8705 3.2513
pair_coeff 5 7 0.0 1.7766
pair_coeff 5 8 0.0 1.7766
pair_coeff 6 7 0.0 0.0
pair_coeff 6 8 0.0 0.0
pair_coeff 7 8 0.0 0.0
neighbor 5.0 bin
neigh_modify delay 0 every 1 one 10000 check yes
#pair_modify mix arithmetic tail no
#------------ define groups ------------------xxx
group cao type 1
group st type 2
group ob type 3
group obts type 4
group oh type 5
group o* type 6
group h* type 7
group ho type 8
group water type 6 7
group solid subtract all water
compute mobile_temp all temp
variable temp equal “300” # Kelvin
velocity all create ${temp} 12345 temp mobile_temp dist gaussian mom no rot no
#------------------energy minimization-----------------------------xxx
#------------------NVE + Temp/rescale------------------------------xxx
minimize 1.0e-4 1.0e-6 100 1000
min_style cg
min_modify dmax 0.1
reset_timestep 0
fix 1 all temp/rescale 1 {temp} {temp} 1.0 0.5
fix 2 all npt temp 300 300 1 iso 0 0 1 drag 1
thermo 100
run 1000
unfix 1
unfix 2
#--------------Strain Calc-----------------------#
variable tmp equal “lx”
variable l0x equal ${tmp}
variable erate equal 1.0e10
variable erate1 equal v_erate/1.0e15
variable p1 equal “pxx/10000”
variable strainx equal “(lx-v_l0x)/v_l0x”
compute p all stress/atom NULL
compute p1 all reduce sum c_p[1] c_p[2] c_p[3]
variable pr equal -(c_p1[1]+c_p1[2]+c_p1[3])/(3*vol)
variable stressx equal -c_p1[1]/10000/vol
variable p equal “pxx”
#----------------Deformation--------------------#
reset_timestep 0
fix 3 all npt temp 300 300 1 y 0 0 1 z 0 0 1 drag 1
fix 4 all deform 1 x erate ${erate1} units box remap x
thermo 100
thermo_style custom step v_strainx v_stressx
run 30000
write_data data.14t_const pair ii