We compute, based on density-functional electronic-structure calculations, the Coulomb couplings in the h, highest occupied orbital of molecular C(60). We obtain a multiplet-averaged Hubbard U approximate to 3 eV, and four Hund-rule-like intramolecular multiplet-splitting terms, each of the order of a few hundred millielectronvolts. According to these couplings, all C(60)(n+) ions should possess a high-spin ground state if kept in their rigid undistorted form. Even after molecular distortions are allowed, however, the Coulomb terms still appear to be somewhat stronger than the previously calculated Jahn-Teller couplings, the latter favouring low-spin states. Thus for example in C(60)(2+), unlike C(60)(2-), the balance between the Hund rule and Jahn-Teller yields, even if marginally, a high-spin ground state. That seems surprising in view of reports of superconductivity in field-doped C(60)(n+) systems.
Coulomb couplings in positively charged fullerene / Luders, M; Bordoni, A; Manini, N; Dal Corso, Andrea; Fabrizio, Michele; Tosatti, E.. - In: PHILOSOPHICAL MAGAZINE. B. PHYSICS OF CONDENSED MATTER. STATISTICAL MECHANICS, ELECTRONIC, OPTICAL AND MAGNETIC PROPERTIES. - ISSN 1364-2812. - 82:15(2002), pp. 1611-1647. [10.1080/1364281021000020262]
Coulomb couplings in positively charged fullerene
Dal Corso, Andrea;Fabrizio, Michele;
2002-01-01
Abstract
We compute, based on density-functional electronic-structure calculations, the Coulomb couplings in the h, highest occupied orbital of molecular C(60). We obtain a multiplet-averaged Hubbard U approximate to 3 eV, and four Hund-rule-like intramolecular multiplet-splitting terms, each of the order of a few hundred millielectronvolts. According to these couplings, all C(60)(n+) ions should possess a high-spin ground state if kept in their rigid undistorted form. Even after molecular distortions are allowed, however, the Coulomb terms still appear to be somewhat stronger than the previously calculated Jahn-Teller couplings, the latter favouring low-spin states. Thus for example in C(60)(2+), unlike C(60)(2-), the balance between the Hund rule and Jahn-Teller yields, even if marginally, a high-spin ground state. That seems surprising in view of reports of superconductivity in field-doped C(60)(n+) systems.File | Dimensione | Formato | |
---|---|---|---|
pmb_82_1611_2002.pdf
non disponibili
Licenza:
Non specificato
Dimensione
500.33 kB
Formato
Adobe PDF
|
500.33 kB | Adobe PDF | Visualizza/Apri Richiedi una copia |
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.