th_tth (ThTthSolver)#

Caution

work-in-progress

Backend: th_tth ("th_tth")

Transformations between \(\theta,2\theta\) and \(Q\).

Example:

import hklpy2
SolverClass = hklpy2.get_solver("th_tth")
solver = SolverClass()

ThTthSolver(geometry, **kwargs)

"th_tth" (any OS) \(\theta,2\theta\) and \(Q\).

class hklpy2.backends.th_tth_q.ThTthSolver(geometry: str, **kwargs)[source]#

Bases: SolverBase

"th_tth" (any OS) \(\theta,2\theta\) and \(Q\).

transformation	equation
`forward()`	\(\theta = \sin^{-1}(q\lambda / 4\pi)\)
`inverse()`	\(q = (4\pi / \lambda) \sin(\theta)\)

Wavelength is specified either directly (solver.wavelength = 1.0) or by adding at least one reflection (see Reflection). All reflections must have the same wavelength.

No orientation matrix is used in this geometry.

Python Methods

`addReflection`(value)	Add coordinates of a diffraction condition (a reflection).
`calculate_UB`(r1, r2)	Calculate the UB (orientation) matrix with two reflections.
`extra_axis_names`	Ordered list of any extra axis names (such as x, y, z).
`forward`(pseudos)	Transform pseudos to list of reals.
`geometries`()	Ordered list of the geometry names.
`inverse`(reals)	Transform reals to pseudos.
`pseudo_axis_names`	Ordered list of the pseudo axis names (such as h, k, l).
`real_axis_names`	Ordered list of the real axis names (such as th, tth).
`refineLattice`(reflections)	No lattice refinement in this Solver.
`removeAllReflections`()	Remove all reflections.

Python Properties

`geometry`	Diffractometer geometry.
`lattice`	Crystal lattice parameters.
`mode`	Diffractometer geometry operation mode for `forward()`.
`modes`	List of the geometry operating modes.
`sample`	Crystalline sample.

property UB#: Orientation matrix (3x3).

addReflection(value: Reflection)[source]#: Add coordinates of a diffraction condition (a reflection).

calculate_UB(r1, r2)[source]#

Calculate the UB (orientation) matrix with two reflections.

The method of Busing & Levy, Acta Cryst 22 (1967) 457.

property extra_axis_names#: Ordered list of any extra axis names (such as x, y, z).

forward(pseudos: dict) → list[dict[str, float]][source]#: Transform pseudos to list of reals.

classmethod geometries()[source]#

Ordered list of the geometry names.

EXAMPLES:

>>> from hklpy2 import get_solver
>>> Solver = get_solver("no_op")
>>> Solver.geometries()
[]
>>> solver = Solver("TH TTH Q")
>>> solver.geometries()
[]

property geometry: str#: Diffractometer geometry.

inverse(reals: dict)[source]#: Transform reals to pseudos.

property lattice: object#: Crystal lattice parameters. (Not used by this Solver.)

property mode: str#

Diffractometer geometry operation mode for forward().

A mode defines which axes will be modified by the forward() computation.

property modes#: List of the geometry operating modes.

name = 'th_tth'#: Name of this Solver.

property pseudo_axis_names#: Ordered list of the pseudo axis names (such as h, k, l).

property real_axis_names#: Ordered list of the real axis names (such as th, tth).

refineLattice(reflections: list[Reflection]) → None[source]#: No lattice refinement in this Solver.

removeAllReflections()[source]#: Remove all reflections.

property sample: object#: Crystalline sample.

version = '0.0.25.dev83+gf26812c'#: Version of this Solver.

property wavelength#: Diffractometer wavelength, for forward() and inverse().