MagMC

Presenting MagMC, the simulation tool for performing Markov Chain Monte Carlo simulations on lihium orthophosphates. This repo has been copied over from an earlier Gitlab repository at https://gitlab.gbar.dtu.dk/s134272/MagMC

Run the program with the following command:

java -jar MCMC_Mag.jar

Then the commands to run can be input. Every command argument starting with a # as the first character will be treated as a comment. (This makes it possible to input commands from a file.)

List of commands:

	disableConfigFile, disableVis, enableConfigFile, enableVis, help, loadConfigFile, mkDir, modifyelement, printDir, printParam, resetDir, saveConfigFile, scanBx, scanBy, scanBz, scanT, setDir, setParam, setVars. scananglebyz, scantbx, repeat/setrepeat, printparam, printvar, printdir, resetdir, mkdir, loadconfigfile, saveconfigfile, savecurrentconfig, enableconfigfile, disableConfigFile, enableSaveAllConfigs, disableSaveAllConfigs, 
	disableVis, disablePeriodic, enablePeriodic, runsim, wait, exit

Description:

• help
  • Displays this text.
• setCommonParam MCS N_x N_y N_z ELEM
  • Sets the configuration for the simulation, that is the number of monte carlo steps, MCS, the dimensions N_x N_y and N_z, and the default element ELEM for the array. The element can be either Co, Ni, Fe or Mn (and case matters).
• printParam
  • Prints the parameters for the configuration and the atom array.
• setCommonVars T B_x B_y B_z
  • Sets the default values for the thermodynamic parameters, T, B_x, B_y, B_z,
  • where B is the external applied magnetic field.
• scanpoint
• scanT T_start dT T_end
  • Makes a scan ramping up or down the temp, starting at T_start.
• scanB[x/y/z]
  • Makes a scan ramping up or down the x/y/z- component of the applied field.
  • The scan starts at B_start ends at B_end, and increments by dB.
• scanTB[x/y/z] T_start dT T_end B_start dB B_end
  • Makes a scan over a square in T-B space, over the interval
  • [T_start, T_end] x [B_start, B_end] with increments of dT and dB.
• scanAngleB[x/y/z][x/y/z] Theta_start dTheta Theta_end
  • Makes a scan over different angles for the applied magnetic field. The angle is varied from Theta_start to Theta_end in increments of dTheta.
• modifyelement ELEM PARAM VALUE
  • Modify the parameter given by PARAM of the element ELEM, to be the value VALUE. The parameters are numbered as: 0: Ja, 1: Jb, 2: Jc, 3: Jbc, 4: Jac, 5: Jab, 6: Da, 7: Db, 8: Dc e.g. to change the Jbc of Co to be 0.4, do modifyelement Co 3 0.4
• setRepeat NUM
  • Sets that each simulation should be repeated a number of times given by NUM. (In effect multiplies the points added to the queue.)
• enableVis/disableVis
  • Enables or disables the use of a visualiser. If run on a computer cluster, this should be disabled. Is disabled by default.
• enablePeriodic/disablePeriodic
  • Enables or disables periodic boundary conditions. Is enabled by default.
• loadConfigFile FILE
  • Loads in the configuration of the atom array from a config-file FILE. This loads both what element should be at each position and the direction of the spin.
• saveCurrentConfig FILE
  • Saves the configuration of the atom array to a config-file FILE. This saves both what element are at each position and the direction of the spin.
• mkDir DIR
  • Attempts to create the directory given by the string DIR.
• resetDir
  • Resets the directory for where to save results, to the default location. (This is a folder named Data, which is created if it does not exist)
• printDir
  • Prints the default directory for which to save the results,
• printVars
  • Prints the current queue of [T,B]-points to simulate.
• enableConfigFile/disableConfigFile
  • Enable/disable the use of a file for saving the configuration. If not set
• enableSaveAllConfigs/disableSaveAllConfig
• runSim [FILE]
  • Starts the simulation, with a copy of the current queue of [T,B]-points to simulate. If the optional parameter FILE is given, the results are saved there, otherwise result will be printed to standard out/system.out
• wait
  • Halts the program for 10 seconds. Intended for inspecting visually the resulting magnetic ordering. Cannot be used while a simulation is underway.
• exit/quit
  • Quits the program.

Example usage:

    setCommon 1000 6 6 6 Co
    setVars 2 0 0 0
    scanT 30 -0.1 2
    runSim results.dat
    exit