Dear Lammps users,
I am using core-shell model for Barium titanat oxide, i would like to build the model same as figure 6 in . It’s a cantilever beam, one side is fixed, the another side is free and after relaxation a downward force will apply to the free end. However during relaxation the corner atoms at the free end fly away and blowing up the temperature.
Details of my model:
1.Core-shell model for Barium titanat oxide, the core-shell requires periodic boundary for all direction. In order to study the size effect, sufficient vacuum space created around the model.
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temperature is applied through nvt. I also tried with temp/rescale, same thing happens.
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The system is not charge neutral due to free surfaces.
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Potential used from DOI: 10.1063/1.4827475
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code of relaxation:
compute temperature only for the mobile part (exclude the fixed end)
compute CSequ mobile temp/cs mobile_cores mobile_shells
velocity bias option
variable T_start equal 415
velocity mobile create ${T_start} 134 dist gaussian mom yes rot yes bias yes temp CSequ
velocity mobile scale ${T_start} temp CSequ
velocity fixed set 0 0 0
fix setforce_fixed fixed setforce 0.0 0.0 0.0
fix nve all nve
fix temp_mobile mobile temp/rescale 100 {T_start} {T_start} 1 0.5
fix mom_mobile mobile momentum 10 linear 0 0 0 angular
fix_modify temp_mobile temp CSequ
thermo_modify temp CSequ
timestep 0.004
run 1000
Any suggestion is appreciated.
Best regards
Bo