`chfl_cell` type¶

type chfl_cell¶

A chfl_cell represent the box containing the atoms, and its periodicity. An unit cell is fully represented by three lengths (a, b, c); and three angles (alpha, beta, gamma). The angles are stored in degrees, and the lengths in Angstroms.

Type fields:

% init [subroutine] :: chfl_cell%init()
% copy [subroutine] :: chfl_cell%copy()
% from_matrix [subroutine] :: chfl_cell%from_matrix()
% lengths [function] :: chfl_cell%lengths()
% set_lengths [subroutine] :: chfl_cell%set_lengths()
% angles [function] :: chfl_cell%angles()
% set_angles [subroutine] :: chfl_cell%set_angles()
% matrix [function] :: chfl_cell%matrix()
% shape [function] :: chfl_cell%shape()
% set_shape [subroutine] :: chfl_cell%set_shape()
% volume [function] :: chfl_cell%volume()
% wrap [subroutine] :: chfl_cell%wrap()
% free [subroutine] :: chfl_cell%free()

subroutine chfl_cell%init(lengths[, angles, status])¶

Initialize this unit cell with an unit cell having the given lengths and optional angles. If all angles are 90°, the unit cell shape is CHFL_CELL_ORTHORHOMBIC, else it is CHFL_CELL_TRICLINIC.

This subroutine allocate memory which must be released with chfl_cell%free().

Parameters:

lengths (3) [real] :: cell lengths, in angstroms

Options:

angles (3) [real] :: cell angles, in degrees
status [integer(chfl_status)] :: status code of the operation. If it is not CHFL_SUCCESS, use chfl_last_error() to learn more about the error.

subroutine chfl_cell%copy(cell[, status])¶

Initialize this unit cell with a copy of cell. This subroutine allocate memory which must be released with chfl_cell%free().

Parameters:: cell [type(chfl_cell)] :: cell to copy
Options:: status [integer(chfl_status)] :: status code of the operation. If it is not CHFL_SUCCESS, use chfl_last_error() to learn more about the error.

subroutine chfl_cell%from_matrix(matrix[, status])¶

Initialize this unit cell from it’s matricial representation, i.e the matrix containing the three cell vectors. This subroutine allocate memory which must be released with chfl_cell%free().

Parameters:: matrix (3, 3) [real(kind=real64)] :: matrix representation of the unit cell
Options:: status [integer(chfl_status)] :: status code of the operation. If it is not CHFL_SUCCESS, use chfl_last_error() to learn more about the error.

function chfl_cell%volume([status])¶

Get the volume of the unit cell in angstroms cubes.

Return:: real
Options:: status [integer(chfl_status)] :: status code of the operation. If it is not CHFL_SUCCESS, use chfl_last_error() to learn more about the error.

function chfl_cell%lengths([status])¶

Get the unit cell lengths in angstroms.

Return:: real (3)
Options:: status [integer(chfl_status)] :: status code of the operation. If it is not CHFL_SUCCESS, use chfl_last_error() to learn more about the error.

subroutine chfl_cell%set_lengths(lengths[, status])¶

Set the unit cell lengths to lengths.

Parameters:: lengths (3) [real] :: new cell lengths, in angstroms
Options:: status [integer(chfl_status)] :: status code of the operation. If it is not CHFL_SUCCESS, use chfl_last_error() to learn more about the error.

function chfl_cell%angles([status])¶

Get the unit cell angles in degrees.

Return:: real (3)
Options:: status [integer(chfl_status)] :: status code of the operation. If it is not CHFL_SUCCESS, use chfl_last_error() to learn more about the error.

subroutine chfl_cell%set_angles(alpha, beta, gamma[, status])¶

Set the cell angles to angles. Trying to set cell angles on a cell which is not triclinic (does not have the CHFL_CELL_TRICLINIC shape) is an error.

Parameters:: angles (3) [real] :: new cell angles, in degrees
Options:: status [integer(chfl_status)] :: status code of the operation. If it is not CHFL_SUCCESS, use chfl_last_error() to learn more about the error.

function chfl_cell%matrix([status])¶

Get the unit cell matricial representation.

The unit cell representation is obtained by aligning the a vector along the x axis and putting the b vector in the xy plane. This make the matrix an upper triangular matrix:

| a_x b_x c_x |
|  0  b_y c_y |
|  0   0  c_z |

Return:: real (3, 3)
Options:: status [integer(chfl_status)] :: status code of the operation. If it is not CHFL_SUCCESS, use chfl_last_error() to learn more about the error.

function chfl_cell%shape([status])¶

Get the unit cell shape.

Return:: integer (chfl_cellshape)
Options:: status [integer(chfl_status)] :: status code of the operation. If it is not CHFL_SUCCESS, use chfl_last_error() to learn more about the error.

The cell shapes are integers which kind is the chfl_cellshape parameter.

chfl_cellshape [integer]¶: Integer kind parameter for representing unit cel shape.

CHFL_CELL_ORTHORHOMBIC [integer(chfl_cellshape)]¶: Cell shape for cell where the three angles are 90°

CHFL_CELL_TRICLINIC [integer(chfl_cellshape)]¶: Cell shape for cell where the three angles may not be 90°

CHFL_CELL_INFINITE [integer(chfl_cellshape)]¶: Cell type when there is no periodic boundary conditions

subroutine chfl_cell%set_shape(shape[, status])¶

Set the unit cell shape to shape

Parameters:: shape [integer(chfl_cellshape)] :: the new shape of the cell
Options:: status [integer(chfl_status)] :: status code of the operation. If it is not CHFL_SUCCESS, use chfl_last_error() to learn more about the error.

subroutine chfl_cell%wrap(vector[, status])¶

Wrap a vector in this unit cell so that all its components are beteen -L/2 and L/2.

Parameters:: vector (3) [real] :: vector to wrap in the cell
Options:: status [integer(chfl_status)] :: status code of the operation. If it is not CHFL_SUCCESS, use chfl_last_error() to learn more about the error.

subroutine chfl_cell%free()¶: Destroy an unit cell, and free the associated memory

chfl_cell type¶

`chfl_cell` type¶