Esempio n. 1
0
# set up angle interactions according to the parameters read from the .top file
angleinteractions = gromacs.setAngleInteractions(system, angletypes,
                                                 angletypeparams)

# set up coulomb interactions according to the parameters read from the .top file
# !! Warning: this only works for reaction-field now!
qq_interactions = gromacs.setCoulombInteractions(system,
                                                 verletlist,
                                                 rc,
                                                 types,
                                                 epsilon1=1,
                                                 epsilon2=80,
                                                 kappa=0)

# set up bonded interactions according to the parameters read from the .top file
bondedinteractions = gromacs.setBondedInteractions(system, bondtypes,
                                                   bondtypeparams)

# exlusions, i.e. pairs of atoms not considered for the non-bonded part. Those are defined either by bonds which automatically generate an exclusion. Or by the nregxcl variable
verletlist.exclude(exclusions)

# langevin thermostat
langevin = espressopp.integrator.LangevinThermostat(system)
langevin.gamma = 2.0
langevin.temperature = 2.4942  # kT in gromacs units
integrator = espressopp.integrator.VelocityVerlet(system)
integrator.addExtension(langevin)
integrator.dt = timestep

# print simulation parameters
print ''
print 'number of particles =', num_particles
Esempio n. 2
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#ljinteraction=gromacs.setLennardJonesInteractions(system, defaults, atomtypeparameters, verletlist,rc)

########## tabulated nb interactions ############
tabfilesnb = ["table_O_O.xvg", "table_H_O.xvg", "table_H_H.xvg"]
potentials = genTabPotentials(tabfilesnb)
tabulatedinteraction = espressopp.interaction.VerletListTabulated(verletlist)
tabulatedinteraction.setPotential(0, 0, potentials["O_O"])
tabulatedinteraction.setPotential(0, 1, potentials["H_O"])
tabulatedinteraction.setPotential(1, 1, potentials["H_H"])
system.addInteraction(tabulatedinteraction)

# set up angle interactions according to the parameters read from the .top file
angleinteractions=gromacs.setAngleInteractions(system, angletypes, angletypeparams)

# set up bonded interactions according to the parameters read from the .top file
bondedinteractions=gromacs.setBondedInteractions(system, bondtypes, bondtypeparams)

# exlusions, i.e. pairs of atoms not considered for the non-bonded part. Those are defined either by bonds which automatically generate an exclusion. Or by the nregxcl variable
verletlist.exclude(exclusions)

# langevin thermostat
langevin = espressopp.integrator.LangevinThermostat(system)
langevin.gamma = 10
langevin.temperature = 2.4942 # kT in gromacs units
integrator = espressopp.integrator.VelocityVerlet(system)
integrator.addExtension(langevin)
integrator.dt = timestep

print "POT", potentials
pathintegral.createPathintegralSystem(allParticles, props, types, system, langevin, potentials, P=16)