diffpy.Structure.lattice.Lattice

Class Lattice

Lattice --> general coordinate system Data members: a, b, c, alpha, beta, gamma -- read-only lattice parameters, unit cell angles are in degrees. The values of lattice parameters are set by setLatPar() and setLatBase(). ar, br, cr, alphar, betar, gammar -- read-only parameters of reciprocal lattice, set by setLatPar() and setLatBase(). All reciprocal angles are in degrees. ca, cb, cg, sa, sb, sg -- read-only cosines and sines of direct lattice angles, they get set by setLatPar() and setLatBase() car, cbr, cgr, sar, sbr, sgr -- read-only cosines and sines of reciprocal lattice angles, set by setLatPar() and setLatBase() metrics -- metrics tensor base -- matrix of row base vectors in cartesian coordinates, base = stdbase*baserot stdbase -- matrix of base vectors in standard orientation baserot -- base rotation matrix recbase -- inverse of base matrix, its columns are reciprocal vectors in cartesian coordinates normbase -- base with magnitudes of reciprocal vectors recnormbase -- inverse of normbase Note: All data members are read-only, their values get set by calling setLatPar() or setLatBase() methods.

Instance Methods

[hide private]

__init__(self, a=None, b=None, c=None, alpha=None, beta=None, gamma=None, baserot=array([[ 1., 0., 0..., base=None)
define new coordinate system, the default is Cartesian There are 4 ways how to create Lattice instance: Lattice() -- create cartesian coordinates Lattice(a, b, c, alpha, beta, gamma) -- define coordinate system from specified lattice parameters. source code

setLatPar(self, a=None, b=None, c=None, alpha=None, beta=None, gamma=None, baserot=None)
set lattice parameters and all related tensors a, b, c, alpha, beta, gamma -- lattice parameters, unit cell angles are in degrees.

source code

setLatBase(self, base)
Set matrix of unit cell base vectors and calculate corresponding lattice parameters and stdbase, baserot and metrics tensors.

source code

abcABG(self)
Return a tuple of 6 lattice parameters.

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reciprocal(self)
Return the reciprocal lattice to self.

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cartesian(self, u)
return cartesian coordinates of a lattice vector

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fractional(self, rc)
return fractional coordinates of a cartesian vector

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dot(self, u, v)
return dot product of 2 lattice vectors

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norm(self, u)
return norm of a lattice vector

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dist(self, u, v)
Return distance of 2 points in lattice coordinates.

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angle(self, u, v)
Return angle(u, v) --> angle of 2 lattice vectors in degrees.

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__repr__(self)
String representation of this lattice.

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init(self, a=None, b=None, c=None, alpha=None, beta=None, gamma=None, baserot=array([[ 1., 0., 0`...`, base=None)
(Constructor)

source code

define new coordinate system, the default is Cartesian
There are 4 ways how to create Lattice instance:

Lattice()         -- create cartesian coordinates
Lattice(a, b, c, alpha, beta, gamma) -- define coordinate system
                     from specified lattice parameters.  Unit cell
                     angles are all in degrees.
Lattice(base=abc) -- create coordinate system using the given base,
                     abc is a 3x3 matrix (or nested list), of row
                     base vectors
Lattice(lat)      -- create a copy of existing Lattice lat

setLatPar(self, a=None, b=None, c=None, alpha=None, beta=None, gamma=None, baserot=None)

source code

set lattice parameters and all related tensors

a, b, c, alpha, beta, gamma -- lattice parameters, unit cell angles
            are in degrees.
baserot  -- unit cell rotation, base = stdbase*baserot

Note: parameters with value None will remain unchanged.

Return self.

setLatBase(self, base)

source code

Set matrix of unit cell base vectors and calculate corresponding
lattice parameters and stdbase, baserot and metrics tensors.

Return self.

Class Lattice

__init__(self, a=None, b=None, c=None, alpha=None, beta=None, gamma=None, baserot=array([[ 1., 0., 0..., base=None) (Constructor)

setLatPar(self, a=None, b=None, c=None, alpha=None, beta=None, gamma=None, baserot=None)

setLatBase(self, base)

init(self, a=None, b=None, c=None, alpha=None, beta=None, gamma=None, baserot=array([[ 1., 0., 0`...`, base=None)
(Constructor)