Three components are required to describe a crystal structure: More...

#include <CrystalStructure.h>

Public Member Functions
void	addScatterers (const CompositeBraggScatterer_sptr &scatterers)
	Adds all scatterers in the supplied collection into the internal one (scatterers are copied).

UnitCell	cell () const
	Returns the unit cell of the structure.

ReflectionCondition_sptr	centering () const

	CrystalStructure (const std::string &unitCellString, const std::string &spaceGroupString, const std::string &scattererString)
	String-based constructor.

	CrystalStructure (const UnitCell &unitCell, const SpaceGroup_const_sptr &spaceGroup, const CompositeBraggScatterer_sptr &scatterers)
	SpaceGroup/Scatterers constructor.

CompositeBraggScatterer_sptr	getScatterers () const
	Return a clone of the internal CompositeBraggScatterer instance.

void	setCell (const UnitCell &cell)
	Assigns a new unit cell.

void	setScatterers (const CompositeBraggScatterer_sptr &scatterers)
	Remove all scatterers and set the supplied ones as new scatterers.

void	setSpaceGroup (const SpaceGroup_const_sptr &spaceGroup)
	Assigns a new space group to the crystal structure.

SpaceGroup_const_sptr	spaceGroup () const
	Returns the space group of the crystal structure.

Protected Member Functions
void	assignUnitCellToScatterers (const UnitCell &unitCell)
	Assigns the cell to all scatterers.

void	initializeScatterers ()
	Initializes the internal storage for scatterers.

void	setReflectionConditionFromSpaceGroup (const SpaceGroup_const_sptr &spaceGroup)
	Tries to set the centering from the space group symbol or removes the current centering if creation fails.

Protected Attributes
UnitCell	m_cell

ReflectionCondition_sptr	m_centering

CompositeBraggScatterer_sptr	m_scatterers

SpaceGroup_const_sptr	m_spaceGroup

Detailed Description

Three components are required to describe a crystal structure:

1. Unit cell metric
2. Space group
3. Scatterers in the asymmetric unit

Representations for all of these components exist in the MantidGeometry-library separately and this class combines them in order to provide some useful calculations that are common when working with crystal structures.

Besides construction from actual objects, a CrystalStructure object can be constructed from three strings that contain the corresponding information.

The unit cell string must consist of 3 or 6 floating point numbers, which are 3 lenghts in Angström and 3 angles in degree. If the angles are not supplied, they are assumed to be 90 degrees.

The space group string must be a valid space group that is registered into the factory. Lastly, specification of the atoms in the asymmetric unit is required. The format is as follows:

Element x y z Occupancy U_iso;
Element x y z Occupancy U_iso;
...

Element has to be a valid NeutronAtom, x, y and z are fractional coordinates between 0 and 1 (other coordinates will be transformed to that range). It is allowed (and encouraged) to use proper fractions in the coordinates, for example:

Mg 1/3 2/3 1/4 1.0 0.05;

Occupancy must be given as values between 0 and 1 and U_iso is the isotropic thermal displacement parameter, given in Angrström^2.

Author: Michael Wedel, Paul Scherrer Institut - SINQ

Date: 05/08/2014

Definition at line 66 of file CrystalStructure.h.

Constructor & Destructor Documentation

◆ CrystalStructure() [1/2]

Mantid::Geometry::CrystalStructure::CrystalStructure	(	const UnitCell &	unitCell,
		const SpaceGroup_const_sptr &	spaceGroup,
		const CompositeBraggScatterer_sptr &	scatterers
	)

SpaceGroup/Scatterers constructor.

Definition at line 25 of file CrystalStructure.cpp.

References addScatterers(), initializeScatterers(), setCell(), setSpaceGroup(), and spaceGroup().

◆ CrystalStructure() [2/2]

Mantid::Geometry::CrystalStructure::CrystalStructure	(	const std::string &	unitCellString,
		const std::string &	spaceGroupString,
		const std::string &	scattererString
	)