VerletIntegrator

class openmm.openmm.VerletIntegrator(*args)

This is an Integrator which simulates a System using the leap-frog Verlet algorithm.

__init__(self, stepSize) → VerletIntegrator

__init__(self, other) → VerletIntegrator

Create a VerletIntegrator.

Parameters

stepSize (double) – the step size with which to integrate the system (in picoseconds)

Methods

__init__(-> VerletIntegrator)	Create a VerletIntegrator.
getConstraintTolerance(self)	Get the distance tolerance within which constraints are maintained, as a fraction of the constrained distance.
getIntegrationForceGroups(self)	Get which force groups to use for integration.
getStepSize(self)	Get the size of each time step, in picoseconds.
setConstraintTolerance(self, tol)	Set the distance tolerance within which constraints are maintained, as a fraction of the constrained distance.
setIntegrationForceGroups(groups)	Set which force groups to use for integration.
setStepSize(self, size)	Set the size of each time step, in picoseconds.
step(self, steps)	Advance a simulation through time by taking a series of time steps.

Attributes

thisown

The membership flag

property thisown

The membership flag

step(self, steps)

Advance a simulation through time by taking a series of time steps.

Parameters

steps (int) – the number of time steps to take

getConstraintTolerance(self) → double

Get the distance tolerance within which constraints are maintained, as a fraction of the constrained distance.

getIntegrationForceGroups(self) → int

Get which force groups to use for integration. By default, all force groups are included. This is interpreted as a set of bit flags: the forces from group i will be included if (groups&(1<<i)) != 0.

getStepSize(self) → double

Get the size of each time step, in picoseconds. If this integrator uses variable time steps, the size of the most recent step is returned.

Returns

the step size, measured in ps

Return type

double

setConstraintTolerance(self, tol)

Set the distance tolerance within which constraints are maintained, as a fraction of the constrained distance.

setIntegrationForceGroups(groups)

Set which force groups to use for integration. By default, all force groups are included.

Parameters

groups (set or int) – a set of indices for which force groups to include when integrating the equations of motion. Alternatively, the groups can be passed as a single unsigned integer interpreted as a bitmask, in which case group i will be included if (groups&(1<<i)) != 0.

setStepSize(self, size)

Set the size of each time step, in picoseconds. If this integrator uses variable time steps, the effect of calling this method is undefined, and it may simply be ignored.

Parameters

size (double) – the step size, measured in ps