double_commutator

double_commutator(op_a, op_b, op_c, sign=False)

Compute symmetric double commutator of op_a, op_b and op_c.

See also Equation (13.6.18) in [1]. If sign is False, it returns

$$[[A,B],C]/2+[A,[B,C]]/2=(2ABC+2CBA-BAC-CAB-ACB-BCA)/2.$$

If sign is True, it returns

$$\{[A,B],C\}/2+\{A,[B,C]\}/2=(2ABC-2CBA-BAC+CAB-ACB+BCA)/2.$$

Parámetros:

• op_a (SparseLabelOp) – Operator A.

• op_b (SparseLabelOp) – Operator B.

• op_c (SparseLabelOp) – Operator C.

• sign (bool) – False anti-commutes, True commutes.

Devuelve:

The computed double commutator.

Tipo del valor devuelto:

SparseLabelOp

Referencias

[1]: R. McWeeny.

Methods of Molecular Quantum Mechanics. 2nd Edition, Academic Press, 1992. ISBN 0-12-486552-6.