Input Examples

Example of standard input file (st_input)

1) Simulation of H2O (liquid water).

     In this example, a cubic box of 343 molecules of water is randomly created to be simulated under the NVT ensemble. Information about water molecule is read from file "H2O" and output is written at files H2O-thermal.DAT, H2O-thermal.RES and H2O-thermal.XYZ. Standard thermalization procedure consists of (i) cooling system at initial 150 Monte Carlo steps, (ii) run 3000 Monte Carlo steps to reach an equilibrated system without accumulating any statistical data (for instance, RDF).

     A typical input file for thermalization has the following structure :

#

title = NVT simulation of 343 molecules of water (thermalization)

ljname = H2O

outname = H2O-thermal

seed = 1091

ncores = 2

upbuf = 4

#

init = yes

nmol = 343

dens = 1.00

#

$end

     After reaching an equilibrated state another run is then performed to accumulate statistics of interest and related data. Previously created file H2O-thermal.DAT is read as input for this step, where 70000 Monte Carlo steps are set as shown below : 

#

title = NVT simulation of 343 molecules of water (equilibrium)

ljname = H2O

outname = H2O-343

ncores = 2

upbuf = 4

#

nstep = 70000

$end

     Output files H2O-343.DAT, H2O-343.RES, H2O-343.XYZ and H2O-343.GR contain data for later use. Note that extension XYZ may also be written as XYZ.1 if H2O-343.XYZ already exists. Finally, in the case of need for improved statistics or just a longer run, Dice can easily extend an existent run. For instance, an input for an additional 15000 Monte Carlo steps is similar to the following one :

#

title = NVT simulation of 343 molecules of water (continuation) 

ljname = H2O

outname = H2O-343

ncores = 2

upbuf = 4

#

nstep = 15000

accum = yes

$end