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各位大佬好
我目前在做Al/PTFE复合材料在空气中燃烧机理的相关研究,想借助分子动力学模拟对某些性能参数做一些解释,在学习LAMMPS过程中,一直找不到合适的力场文件(Al/O/C/H/F),在看文献过程中看到了“We used the ReaxFF40,41 reactive force field to investigate the chemical reactions of GO, GF, and Al with GO and GF. Because the entire system contains three different types of materials, multiple ReaxFF
parameters were merged into a single force field (i.e., Al/C/H/O, C/ H/F, and F-O interactions employed by Hong and van Duin,42 Rahnamoun and van Duin,43 and Kim et al.,44 respectively).这么一句话,作者将几个力场中的参数合并到一个力场中,只是怎么实现的呢?附上文章链接:https://dx.doi.org/10.1021/acsami.9b20397 。
同时请各位大佬帮我看看,这么in文件有没有问题,哪里需要修改呢?
############################################################################
# LAMMPS Input file for calculating for Al2O3 and -(CF2-CF2)- system #
# wuth a ReaxFF potential #
############################################################################
####Initialization##########################################################
units real
atom_style charge #模拟条件初始化#
boundary p p p
neighbor 2.5 bin
neigh_modify every 10 delay 0 check no
####define box and create atoms#############################################
read_data data.Al2O3 #构建或读取初始模型#
####define interatomic potential############################################
#### reax args: hbcut hbnewflag tripflag precision
pair_style reax/c NULL checkqeq yes #反应性立场#
pair_coeff * * ffield.reax C C F H C C O Al #反应力场参数输入,参数文件名为ffield.reax#
####define the calculation of the reaction energy###########################
compute reax all pair reax/c #计算与反应有关的全部能量#
####define variable#########################################################
variable eb equal c_reax[1] #定义变量#
variable ea equal c_reax[2]
variable elp equal c_reax[3]
variable emol equal c_reax[4]
variable ev equal c_reax[5]
variable epen equal c_reax[6]
variable ecoa equal c_reax[7]
variable ehb equal c_reax[8]
variable et equal c_reax[9]
variable eco equal c_reax[10]
variable ew equal c_reax[11]
variable ep equal c_reax[12]
variable efi equal c_reax[13]
variable eqeq equal c_reax[14]
####define initial velocity#################################################
velocity all create 298.15 4928459 #给初速度#
####room temperature relaxation#############################################
fix 1 all reax/c/bonds 1000 bonds.reax #输出每个轨迹步系统内原子连接其他原子信息#
fix 2 all nvt temp 298.15 298.15 10.0
fix 3 all qeq/reax 1 0.0 10.0 1e-6 reax/c #对系统电荷平衡校正计算#
dump 1 all custom 1000 trj.cool id type q x y z #输出系统内原子轨迹坐标#
dump_modify 1 sort 1
restart 100 restart1 restart2
thermo 1000
thermo_style custom step cpu temp evdwl ecoul epair etotal press &
v_eb v_ea v_elp v_emol v_ev v_epen v_ecoa v_ehb &
v_et v_eco v_ew v_ep v_efi v_eqeq #输出系统各及与化学反应相关的宏观性质数据#
thermo_modify flush yes
timestep 0.1 #模拟步长#
run 1000000 #模拟步数#
####以上过程为常温下驰豫####################################################
undump 1
unfix 2
unfix 3
####heating process to 3000k################################################
fix 4 all nvt temp 298.15 3000.15 10.0 #采用NVT系综模拟#
fix 5 all qeq/reax 1 0.0 10.0 1e-6 reax/c #对系统电荷平衡校正计算#
dump 2 all custom 1000 trj.heating id type q x y z #输出系统内原子轨迹坐标#
dump_modify 2 sort 1
restart 100 restart3 restart4
thermo 1000
thermo_style custom step cpu temp evdwl ecoul epair etotal press &
v_eb v_ea v_elp v_emol v_ev v_epen v_ecoa v_ehb &
v_et v_eco v_ew v_ep v_efi v_eqeq #输出系统各及与化学反应相关的宏观性质数据#
thermo_modify flush yes
timestep 1 #模拟步长,可根据需要更改#
run 1000000 #模拟步数,可根据自己情况更改#
####以上过程为线性升温至3000k###############################################
undump 2
unfix 4
unfix 5
####3000k simulation########################################################
fix 6 all nvt temp 3000.15 3000.15 10.0
fix 7 all temp/rescale 50 3000.15 3000.15 10.0 1.0
fix 8 all qeq/reax 1 0.0 10.0 1e-6 reax/c
dump 3 all custom 1000 trj.Al2O3_CF2CF2 id type q x y z
dump_modify 3 sort 1
restart 100 restart5 restart6
thermo 1000
thermo_style custom step cpu temp evdwl ecoul epair etotal press &
v_eb v_ea v_elp v_emol v_ev v_epen v_ecoa v_ehb &
v_et v_eco v_ew v_ep v_efi v_eqeq
thermo_modify flush yes
timestep 1
run 10000000
####以上过程为3000k条件下模拟###############################################
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