CELL_DISPL

Exchange cell displacement vectors for simulation boxes.

>CELL_DISPL

Send cell displacement vector to adjust simulation cell origin.

Datatype: MDI_DOUBLE
Quantity: 3
Units: Bohr

Format: The 3 values correspond to the x, y, and z values, respectively, of the simulation cell displacement vector.

The driver sends a displacement vector to the engine, which adjusts the origin of its simulation cell to the value of the displacement vector.

Examples

Python

import mdi

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

# create a list of displacement values
cell_displ = [0.0, 1.0, 1.0]

# send the cell displacement values to the engine
mdi.MDI_Send_Command(">CELL_DISPL", mdi_engine)
mdi.MDI_Send(cell_displ, 3, mdi.MDI_DOUBLE, mdi_engine)

Python (NumPy)

import mdi
import numpy as np

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

# create an array of cell displacement values
cell_displ = np.array([0.0, 1.0, 1.0], dtype=float)

# send the cell displacement values to the engine
mdi.MDI_Send_Command(">CELL_DISPL", mdi_engine)
mdi.MDI_Send(cell_displ, 3, mdi.MDI_DOUBLE, mdi_engine)

C++

#include "mdi.h"
#include <vector>

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

// create an array of cell displacement values
std::vector<double> cell_displ = {0.0, 1.0, 1.0};

// send the cell displacement values to the engine
MDI_Send_Command(">CELL_DISPL", mdi_engine);
MDI_Send(cell_displ.data(), 3, MDI_DOUBLE, mdi_engine);

<CELL_DISPL

Retrieve the cell displacement vector.

Datatype: MDI_DOUBLE
Quantity: 3
Units: Bohr

Format: The 3 values correspond to the x, y, and z values, respectively, of the simulation cell displacement vector.

The engine sends the displacement vector of the origin of its simulation cell to the driver.

Examples

Python

import mdi

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

# receive the cell displacement values from the engine
mdi.MDI_Send_Command("<CELL_DISPL", mdi_engine)
cell_displ = mdi.MDI_Recv(3, 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 cell displacement values
cell_displ = np.zeros(3, dtype=float)

# receive the cell displacement values from the engine
mdi.MDI_Send_Command("<CELL_DISPL", mdi_engine)
mdi.MDI_Recv(3, mdi.MDI_DOUBLE, mdi_engine, buf=cell_displ) 

C++

#include "mdi.h"
#include <vector>

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

// create a buffer to hold the cell displacement values
std::vector<double> cell_displ(3);

// receive the cell displacement values from the engine
MDI_Send_Command("<CELL_DISPL", mdi_engine);
MDI_Recv(cell_displ.data(), 3, MDI_DOUBLE, mdi_engine);