Hi all,
Following partial input script discribes a collision bewteen two unfixed groups. evrything is ok.
My question is how to fix the left group without moving , let right group move and compact on the left group.
I applied the “fix setforce” command to practice it. However, this command make a constraint of deformation for the left group.
i want the right group move and compact on a fixed left group, both of them can deform due to collision.
All your reply are appreciated.
##define two group
group left id <= ***
group right id >= ***
collision between two unfixed group.
fix 4 all nve
velocity left set v_l NULL NULL units box
velocity right set v_r NULL NULL units box
Yao
State Key Laboratory for Mechanical Behavior of Materials
School of Materials Science and Engineering, Xi’an Jiaotong University
Xianning West Road 28, Xi’an, Shaanxi, 710049 China
E-mail：yhl206@…127…
Hi all,
Following partial input script discribes a collision bewteen two
incomplete inputs are useless. your mistake is likely elsewhere. what
is so difficult to understand about this???
i told you several times to not do this and be more concise and
complete in your problem description. if you don't care to respect the
wishes of people that volunteer their time to help you, the you are
not worth that time.
Hi all,
Following input script discribes three groups of atoms. The down and left group were aparted from one block. Down group was fixed by the fix_setforce command and the left and right group were not.
Then relaxed the system and computed the temperature of both left and right group. During second stage relaxation, the temperature of left group raised, and right group decreased. was this phenomenon normal or something was wrong in the input?
All your reply are appreciated.
units real
dimension 3
newton on
boundary p p p
atom_style hybrid charge atomic
timestep 0.5
neighbor 2.0 nsq
neigh_modify delay 0 every 1 check yes
read_data data.TIO
orthogonal box = (-100 -50 -50) to (200 50 50)
1 by 1 by 1 MPI processor grid
732 atoms
region 1 block INF -8 INF INF INF INF units box
region 2 block -8 6 INF INF INF INF units box
group down region 1
group left region 2
group right id >= 367
#---------------Matsui-Akaogi potential-----------------------
pair_style buck/long/coul/long cut long 10.0
pair_coeff 1 1 7.177e+5 0.154 1.210e+2
pair_coeff 1 2 3.911e+5 0.194 2.904e+2
pair_coeff 2 2 2.717e+5 0.234 6.969e+2
pair_modify table 0
kspace_style ewald 1.0e-4
Ewald initialization ...
G vector (1/distance) = 0.233948
estimated absolute RMS force accuracy = 0.0400463
estimated relative force accuracy = 0.000120598
KSpace vectors: actual max1d max3d = 41676 48 456336
Deleted 0 atoms, new total = 732
# ----------------computer energy
compute kineng_left left ke
compute kineng_right right ke
variable COM equal sqrt((v_position_L_x-v_position_R_x)*(v_position_L_x-v_position_R_x)+(v_position_L_y-v_position_R_y)*(v_position_L_y-v_position_R_y)+(v_position_L_z-v_position_R_z)*(v_position_L_z-v_position_R_z))
compute T_left left temp
compute T_right right temp/com
compute G left group/group right kspace yes
#------------------nitial velocity and temp
velocity all create 650.0 123456 dist gaussian units box
velocity down set 0.0 0.0 0.0
###------------------fix---relax--nve+langevin-----------
<b>fix 1 all langevin 650.0 650.0 100.0 123456
fix 3 all nve</b>
thermo 10
thermo_style custom step temp press pe ke etotal v_COM c_T_left c_T_right v_position_R_x v_position_L_x
thermo_modify lost warn
run 5000
Ewald initialization ...
G vector (1/distance) = 0.233948
estimated absolute RMS force accuracy = 0.0400463
estimated relative force accuracy = 0.000120598
KSpace vectors: actual max1d max3d = 41676 48 456336
Memory usage per processor = 59.3772 Mbytes
Step Temp Press PotEng KinEng TotEng COM **T_left T_right** position position
0 650 17.366129 -213979.08 1416.3319 -212562.75 48.68356 655.06939 657.38961 47.343213 -1.3328319
1000 702.65427 2.89944 -214112.36 1531.0641 -212581.29 48.732232 702.62799 667.97969 47.350936 -1.372582
2000 643.76548 -6.4069925 -214121.74 1402.747 -212719 48.796208 633.6014 650.3667 47.361723 -1.4225005
3000 703.40741 -2.669146 -214131.05 1532.7052 -212598.34 48.862564 712.57263 700.07463 47.378913 -1.4675413
4000 639.23676 -44.250022 -214220.79 1392.8791 -212827.91 48.814567 629.87041 644.54775 47.319238 -1.4718727
5000 645.521 -12.020412 -214219.39 1406.5723 -212812.82 48.721674 668.12761 632.92584 47.238412 -1.4587457
Loop time of 5477.41 on 1 procs for 5000 steps with 732 atoms
Total # of neighbors = 87449
Ave neighs/atom = 119.466
Neighbor list builds = 17
Dangerous builds = 0
###-------------------fix---relax--nvt-----------
unfix 1
unfix 3
<b>fix 4 all nvt temp 650.0 650.0 10.0 drag 0.2
fix 2 down setforce 0.0 0.0 0.0</b>
thermo 10
thermo_style custom step temp press pe ke etotal v_COM c_T_left c_T_right v_position_R_x v_position_L_x
WARNING: New thermo_style command, previous thermo_modify settings will be lost (../output.cpp:663)
thermo_modify lost warn
dump 1 all xyz 5000 dump.xyz.*
dump_modify 1 element Ti O
run 30000
Ewald initialization ...
G vector (1/distance) = 0.233948
estimated absolute RMS force accuracy = 0.0400463
estimated relative force accuracy = 0.000120598
KSpace vectors: actual max1d max3d = 41676 48 456336
Memory usage per processor = 59.5559 Mbytes
Step Temp Press PotEng KinEng TotEng COM **T_left T_right** position position
5000 645.521 -12.020412 -214219.39 1406.5723 -212812.82 48.721674 668.12761 632.92584 47.238412 -1.4587457
6000 670.85798 79.499234 -210314.26 1461.7808 -208852.48 48.480958 937.82575 452.57888 47.169016 -1.294666
7000 652.21752 -13.283698 -211864.24 1421.1638 -210443.07 48.331888 1048.9292 323.7213 47.122235 -1.202682
8000 680.30414 -16.394656 -211618.03 1482.3638 -210135.67 48.368902 1114.1419 316.62062 47.084461 -1.280997
9310 639.65367 -17.787578 -211498.22 1393.7875 -210104.43 48.188966 1097.6215 245.15595 47.043526 -1.1348756
Interrupted ...............
Yao
State Key Laboratory for Mechanical Behavior of Materials
School of Materials Science and Engineering, Xi’an Jiaotong University
Xianning West Road 28, Xi’an, Shaanxi, 710049 China
E-mail：yhl206@…127…