VELOCITES#

Exchange atomic velocities.

>VELOCITES#

Send atomic velocities.

Datatype: MDI_DOUBLE
Quantity: 3 * NATOMS
Format: Sequentially ascending order of atom index, with the velocities for each individual atom being provided in xyz order.

The driver sends a set of atomic velocities to the driver, which replaces its atomic velocities with those provided by the driver.

<VELOCITES#

Receive atomic velocities.

Datatype: MDI_DOUBLE
Quantity: 3 * NATOMS
Format: Sequentially ascending order of atom index, with the velocities for each individual atom being provided in xyz order.

The engine sends the velocities of the atoms in its system to the driver.

Examples#

Python

import mdi

# connect to the engine
mdi_engine = mdi.MDI_Accept_Communicator()

# receive the atomic velocities from the engine
mdi.MDI_Send_Command("<VELOCITES", mdi_engine)
velocities = mdi.MDI_Recv(3*NATOMS, mdi.MDI_DOUBLE, mdi_engine)

Python (NumPy)

import mdi
import numpy as np

# connect to the engine
mdi_engine = mdi.MDI_Accept_Communicator()

# create a buffer to hold the atomic velocities
velocities = np.zeros(3*NATOMS, dtype=float)

# receive the atomic velocities from the engine
mdi.MDI_Send_Command("<VELOCITES", mdi_engine)
mdi.MDI_Recv(3*NATOMS, mdi.MDI_DOUBLE, mdi_engine, buf=velocities

C++

#include "mdi.h"

// connect to the engine
MDI_Comm mdi_engine = MDI_Accept_Communicator();

// create a buffer to hold the atomic velocities
double velocities[3*NATOMS];

// receive the atomic velocities from the engine
MDI_Send_Command("<VELOCITES", mdi_engine);
MDI_Recv(velocities, 3*NATOMS, MDI_DOUBLE, mdi_engine);