#AtC Thermal Coupling # This benchmark tests thermostats applied in all atom simulations. The # temperature is initially 20 everywhere and the left boundary BC is fixed at # 40.# The result should show heat diffusing through the FEM to the MD and back # out # to the FEM on the right. Insufficient time is captured to reach the # linear # steady state, but heat crossing both boundaries should be observed. units real atom_style atomic # create domain #lattice type reduced density rho* = 4*(sigma/a)^3, where N=4 for fcc, s = 3.405 A (Wagner) and a = 5.25 A (Ashcroft & Mermin, p. 70) # NOTE following 3 lines added for restart boundary f p p pair_style lj/cut 13.5 read_data all_atoms.init lattice fcc 5.405 origin 0.25 0.25 0.25 region simRegion block -7 7 -3 3 -3 3 # create atoms, NOTE commented out for restart #boundary f p p #create_box 1 simRegion #create_atoms 1 region simRegion #mass 1 39.95 # specify interal/ghost atoms region mdInternal block -6 6 -3 3 -3 3 group internal region mdInternal group ghost subtract all internal # velocities have Vcm = 0, NOTE next four lines commented out for restart #velocity internal create 40. 87287 mom yes loop geom #pair_style lj/cut 13.5 ##pair_coeff 1 1 0.010323166 3.405 13.5 #pair_coeff 1 1 .238 3.405 13.5 #write_restart all_atoms.init neighbor 5. bin neigh_modify every 10 delay 0 check no # ID group atc PhysicsType ParameterFile fix AtC internal atc thermal Ar_thermal.mat # ID part keywords nx ny nz region fix_modify AtC mesh create 6 1 1 mdInternal f p p fix_modify AtC mesh create_faceset obndy box -6.0 6.0 -INF INF -INF INF outward fix_modify AtC mesh create_faceset lbndy box -6.0 16.0 -INF INF -INF INF outward fix_modify AtC mesh create_faceset rbndy box -16.0 6.0 -INF INF -INF INF outward # fix a temperature fix_modify AtC fix temperature all 20. # turn on thermostat fix_modify AtC control thermal rescale 10 fix_modify AtC internal_quadrature off # equilibrate MD field #dump D1 all atom 100 dump.bar1d #fix_modify AtC output bar1dfe 100 #fix_modify AtC time_integration frac_step timestep 5 variable xdof equal 3*count(ghost) compute_modify thermo_temp extra ${xdof} thermo_style custom step cpu etotal pe f_AtC[1] temp f_AtC[2] thermo_modify format 1 %6i format 2 %7.2g thermo 100 run 400 # change thermostat to hoover fix_modify AtC control thermal hoover #fix_modify AtC thermal control flux interpolate #fix_modify AtC thermal control flux faceset obndy fix_modify AtC filter scale 1000.0 #fix_modify AtC filter equilibrate #fix_modify AtC filter on #fix_modify AtC localized_lambda on fix_modify AtC boundary_faceset is obndy # initialize filter #fix_modify AtC output bar1d_all_atoms_preqFE 1 reset_timestep 0 thermo 1 #run 5000 # add nodesets and ramp temperature # ID mesh create_nodeset tag xmin xmax ymin ymax zmin zmax #fix_modify AtC mesh create_nodeset lbc -6.1 -5.9 -INF INF -INF INF #fix_modify AtC mesh create_nodeset rbc 5.9 6.1 -INF INF -INF INF #fix_modify AtC fix temperature lbc temporal_ramp 20. 40. 25000. #fix_modify AtC fix temperature rbc 20. # initialize filter #fix_modify AtC output bar1d_all_atoms_eqFE 200 reset_timestep 0 fix_modify AtC reset_time #run 5000 # release and let run #fix_modify AtC filter on fix_modify AtC unfix temperature all #fix_modify AtC localized_lambda on fix_modify AtC control lumped_lambda_solve on # dirichlet boundaries #fix_modify AtC fix temperature lbc 40. #fix_modify AtC fix temperature rbc 20. # neumann boundaries fix_modify AtC control thermal flux no_boundary fix_modify AtC fix_flux temperature lbndy 0.0000000001 fix_modify AtC fix_flux temperature rbndy -0.0000000001 # set up output, should be before a "run" fix_modify AtC output bar1d_all_atomsFE 200 text binary # ouput command #dump D1 all atom 1000 dump.bar1d # run with FE reset_timestep 0 thermo 200 run 5000