therm  (see therm.f)
--------------------------------------------------------------------
* thermostat settings
0  thermostat off
1  thermostat on, constant temperature  (set by temp)
2  thermostat on, linear ramp
3  thermostat on, power law
4  special thermostat for edge atoms only

temp
--------------------------------------------------------------------
temperature (in K) for thermostat

ntakof  (see readcoords.f)
--------------------------------------------------------------------
* this determines what data is read from the START file at the beginning of 
* the simulation (also see msd below)
0  use atom postions only, set velocities to zero, set MSD to zero
1  use atom positions and velocities from file, set MSD to zero
2  use atom postions, velocities and MSD data from file

calcstress
--------------------------------------------------------------------
0  do not calculate or print stress
1  calculate and print stress tensor and hydrostatic/biaxial values

nprint  *must be >= 1*
--------------------------------------------------------------------
number of steps between outputs to:
- out
- gr
- theta

nsnap  *must be >= 1*
--------------------------------------------------------------------
number of steps between outputs to:
- in.bs / in.mv

msd
--------------------------------------------------------------------
* this is different to ntakof - ntakof applies to the start of the simulation 
* and whether or not the msd data from the START file will be used
* msd is used to determine behaviour for each 'run' within this input file
0  reset msd
1  use msd from previous run

gr
--------------------------------------------------------------------
0  do not accumulate statistics for g(r) and P(theta) files 
    (these files will be written every nprint steps, but will contain zeros)
1  accumulate statistics for g(r) and P(theta) files

h 
--------------------------------------------------------------------
timestep in reduced time units
real time step (in fs) = h * TIME  
TIME = 35.3 fs

TIME is the reduced time unit, it is output at the start of the out file
TIME=timetau=1e12*1e-10*sqrt(AMASS/1.6e-19)
AMASS = carbon mass in kg =12.01*1.66e-27 = 1.99e-26
1.6e-19 = electronic charge in C

nstep
--------------------------------------------------------------------
total number of timesteps per run
real total length of run (in fs) = nstep * h * TIME
