Example

Here is an example of *mcphas.ini*, the comments describe the meaning of the different
parameters:

#<!--mcphase.mcphas.ini--> [MCPHASE RUNTIME CONTROL] # to stop program set exit to 1 exit=0 # to hold program set pause to 1 pause=0 # to display all structures while iterating set displayall to 1 # (mind that by using this option mcphas gets very slow) displayall=0 # to create a logfile of the propagation versus free energy set logfevsQ to 1 # (mind this uses a lot of disc space) logfevsQ=0 [XY PHASEDIAGRAM PARAMETERS] # xy phasediagram axes - parameters # structures are calculated in the xy - phasediagram # the direction of x and y can be chosen: # vector in (H-T) space corresponding to x axis (xT [K] xHa [T] xHb [T] xHc [T]) xT=1 xHa=0 xHb=0 xHc=0 # range of x xmin=2 xmax=8 xstep=0.2 # vector in (H-T) space corresponding to y axis (yT [K] yHa [T] yHb [T] yHc [T]) yT=0 yHa=0 yHb=1 yHc=0 # range of y ymin=0 ymax=4 ystep=0.2 # offset T0=0 Ha0=0 Hb0=0 Hc0=0 [GENERATION OF SPIN CONFIGURATIONS] # test q vector (qmin qmax deltaq) hmin=0 hmax=0 deltah=0.05 kmin=0 kmax=0 deltak=0.05 lmin=0 lmax=1 deltal=0.02 # maximal periodicity of spinconfigurations generated by q vectors maxqperiod=30 # maximal number of test spinconfigurations maxnoftestspincf=1000 # maximal number of spins in spinconfigurations generated by q vectors maxnofspins=270 # number of random (Monte Carlo) spin inversions to try for each initial spinconfiguration nofrndtries=5 [PARAMETERS FOR SUB FECALC SELFCONSISTENCY PROCESS] # (optional) number of parallel threads on your machine # (if not set program will attempt to determine this automatically) # nofthreads=2 # maximum number of selfconsistency loops maxnofmfloops=1000 # standard deviation - limit to end selfconsistency process # standard deviation is defined by ...sta=sqrt(sum_{i=1}^{n} (newmf-old mf)i^2/n) # the meanfield is given by mf=gj mb H [meV] (gj...lande factor, mb... bohr magneton) maxstamf=1e-05 # step ratio (bigstep=actual step/calculated step) to perform actually # (in case the sta increases in subsequent steps the program steps only # smallstep=0.2xbigstep for ten steps and then again with bigstep # if bigstep is set >1, then only the digits after the comma are relevant # the digits before the comma give the ratio of bigstep/smallstep bigstep=1 # sum_{i=1}^{n} abs(actual change of angular momentum <Ji> with respect to # initial configuration) > maxspinchange will end selfconsistency process maxspinchange=60 [OUTPUT OF PHYSICAL PROPERTIES] # output of physical properties to compare with experiment # 1. For thermal expansion and magnetostriction # how many spinspin correlation functions # should be calculated nofspincorrs=2 # 2. For Neutron Diffraction # calculation of mxnofhkl strongest reflections maxnofhkls=10 # maximum scattering vector |Q|[1/A] for calculated hkl's maxQ=1

Martin Rotter 2017-01-10