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标题: 求助：对水合物进行拉伸，屈服强度过大 [打印本页]

作者
Author: sj12138 时间: 2024-1-18 15:35
标题: 求助：对水合物进行拉伸，屈服强度过大
各位大佬，我是对水合物进行拉伸，但是拉伸之后，屈服强度过高，这是什么原因那？应该如何解决那？

以下给出in文件。

units    real
variable in    equal 270
variable T    equal ${in}
variable P    equal 98.69
variable  Tdump equal 100
variable  Pdump equal 1000
variable  thermo  equal 200
variable  runnvt  equal 20000
variable  runnpt equal 40000
variable  runten  equal 10000000

variable V    equal vol
variable dt equal 1
variable etol equal  etotal
variable han equal  enthalpy
variable T0 equal  temp
variable P0 equal  press
variable  istep equal  step
variable den equal  density
variable PE equal pe

atom_style    full
dimension       3
boundary       p p p
read_data    ${data}

#PROSET
timestep       ${dt}
neigh_modify every 1 delay 0 check yes

#minimize
min_style    sd
minimize       1.0e-20 1.0e-20 100000 100000
fix       mom  all  momentum 10 linear 1 1 1 angular
fix 1 all box/relax iso 0.0
velocity       all  create $T $R mom yes rot yes dist gaussian
velocity       all  scale $T
fix em all print 1  "${istep} ${etol} ${han} ${T0} ${V} ${PE} press" screen no file em_${name}.dat
run 0
unfix  em
unfix 1
fix    shake       all    shake    0.0001 20 0 b 1 a 1

#NVT
thermo_style custom time atoms step temp press vol lx ly lz enthalpy pe ke etotal density evdwl ecoul epair ebond pxx pyy pzz pxy pxz pyz
thermo    ${thermo}
fix       NVT all  nvt  temp ${T} ${T} ${Tdump}
dump       1 all  xyz  ${thermo}  nvt_${name}.xyz
dump       2 watergroup  xyz  ${thermo}  nvt_noch_${name}.xyz
dump       3 CHgroup xyz  ${thermo}  nvt_noh2o_${name}.xyz
dump_modify  1 element OW  HW  C  H
dump_modify  2 element OW  HW  C  H
dump_modify  3 element OW  HW  C  H
fix  vt all print 200 "${istep} ${T0} ${V}" screen no file nvt_${name}.dat
run       ${runnvt}
unfix          NVT
unfix          vt
undump          1
undump          2
undump          3
reset_timestep 0

#npt弛豫
fix       1 all  npt  temp ${T} ${T} ${Tdump} x ${P} ${P} ${Pdump} y ${P} ${P} ${Pdump} z 0 0 1000
thermo_style custom time atoms step temp press vol lx ly lz enthalpy pe ke etotal density evdwl ecoul epair ebond pxx pyy pzz pxy pxz pyz
thermo    ${thermo}
dump       1 all  xyz  ${thermo}  npt_${name}.xyz
dump       2 watergroup  xyz  ${thermo}  npt_noch_${name}.xyz
dump       3 CHgroup xyz  ${thermo}  npt_noh2o_${name}.xyz
dump_modify  1 element OW  HW  C  H
dump_modify  2 element OW  HW  C  H
dump_modify  3 element OW  HW  C  H
fix  npt all print 200  "${istep} ${etol} ${han} ${T0} ${V} ${PE} ${P0}" screen no file npt_${name}.dat
run       ${runnpt}
undump          1
undump          2
undump          3
unfix          npt
unfix          1
reset_timestep 0

#stress-strain
variable tmpz equal "lz"
variable Lz0 equal ${tmpz}
variable strainz equal "(lz - v_Lz0)/v_Lz0"
variable stressz equal "-pzz/10000"

#z向拉伸
fix 2 all npt  temp ${T} ${T} ${Tdump} x ${P} ${P} ${Pdump} y ${P} ${P} ${Pdump}
fix 3 all deform  100  z  erate  0.00000002  remap  x  units  box
thermo_style custom time atoms step temp press vol lx ly lz density pxx pyy pzz pxy pxz pyz
thermo    20000#${thermo}
dump       1 all xyz  20000  tension_${name}.xyz
dump       2 watergroup  xyz  20000  tension_noch_${name}.xyz
dump       3 CHgroup xyz  20000  tension_noh2o_${name}.xyz
dump_modify  1 element OW  HW  C  H
dump_modify  2 element OW  HW  C  H
dump_modify  3 element OW  HW  C  H

#保存应力应变数据
fix  def3  all  print  20000  "${strainz} ${stressz}" screen no file stress-strain_${name}.dat

run          ${runten}

希望大佬们不吝赐教，万分感谢

作者
Author: 牧生 时间: 2024-1-18 18:09
我做的大约0.65 GPa，如果你做的结果单位和我一样，我不认为你的数据有什么异常

作者
Author: sj12138 时间: 2024-1-19 14:25

牧生发表于 2024-1-18 18:09
我做的大约0.65 GPa，如果你做的结果单位和我一样，我不认为你的数据有什么异常

老师您好，感谢您的回复，我的单位是GPa，但是曲线上显示的是6.5

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