### Resumé

Using the time-reversal symmetry operations, we introduce the time-reversal adapted Kramers basis operators X_{pq}^{±} which are the natural expansion set for any relativistic Hermitian or anti-Hermitian one-electron operator and thus replace the spin-adapted basis operators of non-relativistic quantum mechanics. Depending on the time-reversal symmetry or Hermiticity of the one-electron operator, either X^{+} or X^{-}, but never both of them, appear in the expansion, thus causing the symmetry blocking that is important for computational saving in relativistic electronic structure calculations. We determine the combinations of X operators that become irreducible tensor operators in the non-relativistic limit and we use the particle-hole expansion case to offer an interpretation of the new basis as operators that describe simultaneous excitation and deexcitation of particle-hole states with opposite spin-polarization in the non-relativistic limit.

Originalsprog | Engelsk |
---|---|

Tidsskrift | Chemical Physics Letters |

Vol/bind | 232 |

Udgave nummer | 1-2 |

Sider (fra-til) | 47-53 |

Antal sider | 7 |

ISSN | 0009-2614 |

DOI | |

Status | Udgivet - 6. jan. 1995 |

### Fingeraftryk

### Citer dette

*Chemical Physics Letters*,

*232*(1-2), 47-53. https://doi.org/10.1016/0009-2614(94)01332-P

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*Chemical Physics Letters*, bind 232, nr. 1-2, s. 47-53. https://doi.org/10.1016/0009-2614(94)01332-P

**Operator representations in Kramers bases.** / Aucar, G. A.; Jensen, H. J Aa; Oddershede, J.

Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

TY - JOUR

T1 - Operator representations in Kramers bases

AU - Aucar, G. A.

AU - Jensen, H. J Aa

AU - Oddershede, J.

PY - 1995/1/6

Y1 - 1995/1/6

N2 - Using the time-reversal symmetry operations, we introduce the time-reversal adapted Kramers basis operators Xpq± which are the natural expansion set for any relativistic Hermitian or anti-Hermitian one-electron operator and thus replace the spin-adapted basis operators of non-relativistic quantum mechanics. Depending on the time-reversal symmetry or Hermiticity of the one-electron operator, either X+ or X-, but never both of them, appear in the expansion, thus causing the symmetry blocking that is important for computational saving in relativistic electronic structure calculations. We determine the combinations of X operators that become irreducible tensor operators in the non-relativistic limit and we use the particle-hole expansion case to offer an interpretation of the new basis as operators that describe simultaneous excitation and deexcitation of particle-hole states with opposite spin-polarization in the non-relativistic limit.

AB - Using the time-reversal symmetry operations, we introduce the time-reversal adapted Kramers basis operators Xpq± which are the natural expansion set for any relativistic Hermitian or anti-Hermitian one-electron operator and thus replace the spin-adapted basis operators of non-relativistic quantum mechanics. Depending on the time-reversal symmetry or Hermiticity of the one-electron operator, either X+ or X-, but never both of them, appear in the expansion, thus causing the symmetry blocking that is important for computational saving in relativistic electronic structure calculations. We determine the combinations of X operators that become irreducible tensor operators in the non-relativistic limit and we use the particle-hole expansion case to offer an interpretation of the new basis as operators that describe simultaneous excitation and deexcitation of particle-hole states with opposite spin-polarization in the non-relativistic limit.

UR - http://www.scopus.com/inward/record.url?scp=0002007518&partnerID=8YFLogxK

U2 - 10.1016/0009-2614(94)01332-P

DO - 10.1016/0009-2614(94)01332-P

M3 - Journal article

AN - SCOPUS:0002007518

VL - 232

SP - 47

EP - 53

JO - Chemical Physics Letters

JF - Chemical Physics Letters

SN - 0009-2614

IS - 1-2

ER -