magnopy.Convention#

class magnopy.Convention(multiple_counting: bool = None, spin_normalized: bool = None, c1: float = None, c21: float = None, c22: float = None, c31: float = None, c32: float = None, c33: float = None, c41: float = None, c421: float = None, c422: float = None, c43: float = None, c44: float = None, name: str = 'custom')[source]#

Convention of the spin Hamiltonian.

For the detailed description of the convention problem see Convention problem.

Parameters:

multiple_countingbool, optional: Whether the pairs of spins are counted multiple times in the Hamiltonian's sums.
spin_normalizedbool, optional: Whether spin vectors/operators are normalized to 1. If True, then spin vectors/operators are normalized.
c1float, optional: Numerical factor before the (one spin & one site) term of the Hamiltonian.
c21float, optional: Numerical factor before the (two spins & one site) term of the Hamiltonian.
c22float, optional: Numerical factor before the (two spins & two sites) term of the Hamiltonian.
c31float, optional: Numerical factor before the (three spins & one site) term of the Hamiltonian.
c32float, optional: Numerical factor before the (three spins & two sites) term of the Hamiltonian.
c33float, optional: Numerical factor before the (three spins & three sites) term of the Hamiltonian.
c41float, optional: Numerical factor before the (four spins & one site) term of the Hamiltonian.
c421float, optional: Numerical factor before the (four spins & two sites & 1+3) term of the Hamiltonian.
c422float, optional: Numerical factor before the (four spins & two sites & 2+2) term of the Hamiltonian.
c43float, optional: Numerical factor before the (four spins & three sites) term of the Hamiltonian.
c44float, optional: Numerical factor before the (four spins & four sites) term of the Hamiltonian.
namestr, default "custom": A label for the convention. Any string, case-insensitive.

Examples

>>> import magnopy
>>> n1 = magnopy.Convention(True, True, c21=1, c22=-0.5, name="conv #1")
>>> n2 = magnopy.Convention(False, True, c21=1, c22=-0.5, name="conv #2")
>>> n3 = magnopy.Convention(False, True, c22=-0.5, name="conv #3")
>>> print(n1)
"conv #1" convention where
  * Bonds are counted multiple times in the sum;
  * Spin vectors are normalized to 1;
  * Undefined c1 factor;
  * c21 = 1.0;
  * c22 = -0.5;
  * Undefined c31 factor;
  * Undefined c32 factor;
  * Undefined c33 factor;
  * Undefined c41 factor;
  * Undefined c421 factor;
  * Undefined c422 factor;
  * Undefined c43 factor;
  * Undefined c44 factor.
>>> n1.multiple_counting
True
>>> n1 == n2
False
>>> n3.c21
Traceback (most recent call last):
...
magnopy._exceptions.ConventionError: Convention of spin Hamiltonian has an undefined property 'c21':
"conv #3" convention where
  * Bonds are counted once in the sum;
  * Spin vectors are normalized to 1;
  * Undefined c1 factor;
  * Undefined c21 factor;
  * c22 = -0.5;
  * Undefined c31 factor;
  * Undefined c32 factor;
  * Undefined c33 factor;
  * Undefined c41 factor;
  * Undefined c421 factor;
  * Undefined c422 factor;
  * Undefined c43 factor;
  * Undefined c44 factor.
>>> n3.name
'conv #3'

Methods:

`get_modified`([multiple_counting, ...])	Returns the new instance of the `Convention` class based on the called one with changed given properties.
`get_predefined`(name)	Returns one of the pre-defined conventions.
`summary`([return_as_string])	Gives human-readable summary of the convention.

Properties:

`c1`	Numerical factor before the (one spin & one site) sum of the Hamiltonian.
`c21`	Numerical factor before the (two spins & one site) sum of the Hamiltonian.
`c22`	Numerical factor before the (two spins & two sites) sum of the Hamiltonian.
`c31`	Numerical factor before the (three spins & one site) sum of the Hamiltonian.
`c32`	Numerical factor before the (three spins & two sites) sum of the Hamiltonian.
`c33`	Numerical factor before the (three spins & three sites) sum of the Hamiltonian.
`c41`	Numerical factor before the (four spins & one site) sum of the Hamiltonian.
`c421`	Numerical factor before the (four spins & two sites (1+3)) sum of the Hamiltonian.
`c422`	Numerical factor before the (four spins & two sites (2+2)) sum of the Hamiltonian.
`c43`	Numerical factor before the (four spins & three sites) sum of the Hamiltonian.
`c44`	Numerical factor before the (four spins & four sites) sum of the Hamiltonian.
`multiple_counting`	Whether the pairs of spins are counted multiple times in the Hamiltonian's sums.
`name`	A label for the convention.
`spin_normalized`	Whether spin vectors/operators are normalized to 1.

magnopy.Convention#

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