Perhaps the next most important choice is what kind of integration algorithm to use. Above we did a constanttemperature (NVT) algorithm (the actual algorithm is of the NoséHoover type). For constant energy (NVE) runs we create the integrator as follows, here passing only the timestep:
itg = IntegratorNVE(timeStep=0.0025)
(Technical note: this creates an object of the same type as IntegratorNVT,
but here it defaults to NVE modein fact in either case one can switch
thermostatting on or off using the SetThermostatOn()
method).
Additional integrators available in RUMD are listed below
Name of Integrator  Description  Arguments 

IntegratorNVE  The NVE Leapfrog algorithm.  timeStep 
IntegratorNVT  The NosHoover NVT algorithm.  timeStep, targetTemperature 
IntegratorNPTAtomic  NPT algorithm. (JCP 101, N 5, 1994) 
timeStep, targetTemperature, thermostatRelaxationTime, targetPressure, barostatRelaxationTime

IntegratorNVU  Algorithm conserving the total potential energy.  dispLength, potentialEnergy 
IntegratorMMC  Metropolis NVT Monte Carlo.  dispLength, targetTemperature 
IntegratorIHS  Energy minimization via the Leapfrog algorithm.  timeStep 
IntegratorSLLOD  Shear an atomic system in the xyplane using the SLLOD equations.  timeStep, strainRate 
IntegratorMolecularSLLOD  Shear a molecular system in the xyplane using the SLLOD equations.  timeStep, strainRate 
Heine Larsen 20170721