Generalized spin density functional theory for noncollinear molecular magnetism

Yamanaka, Shusuke; Yamaki, Daisuke; Shigeta, Yasuteru; Nagao, Hidemi; Yoshioka, Yasunori; Suzuki, N.; Yamaguchi, Kizashi

doi:10.1002/1097-461x(2000)80:4/5<664::aid-qua15>3.0.co;2-c

Cited by 42 publications

(11 citation statements)

References 43 publications

(50 reference statements)

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“…12 Yamanaka and coworkers developed a generalized DFT code based on Gaussian type orbitals. 13 Some noncollinear DFT calculations have been published dealing with magnetic crystals, 5,10 and with fourth period transition metal clusters. 11,14,15,16 In all cases, the realization of the LSDA and GGA employed in noncollinear calculations is the same as that developed for collinear spin systems.…”

Section: Introductionmentioning

confidence: 99%

Noncollinear magnetism in density functional calculations

Peralta

Scuseria

Frisch³

2007

Phys. Rev. B

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We generalize the treatment of the electronic spin degrees of freedom in density functional calculations to the case where the spin vector variables employed in the definition of the energy functional can vary in any direction in space. The expression for the generalized exchange-correlation potential matrix elements is derived for general functionals which among their ingredients include the electron density, its gradient and Laplacian, the kinetic energy density, and non-local Hartree-Fock type exchange. We present calculations on planar Cr clusters that exhibit ground states with noncollinear spin densities due to geometrically frustrated antiferromagnetic interactions.

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Section: Introductionmentioning

confidence: 99%

Noncollinear magnetism in density functional calculations

Peralta

Scuseria

Frisch³

2007

Phys. Rev. B

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“…For CASSCF calculations, we used GAMESS program package42. The MkMRCCSD calculations were performed by PSIMRCC code43, which has been developed by Evangelista and Simmonett39 and implemented in PSI3 program package44. For UKS‐DFT calculations, Becke88 plus Lee‐Yang‐Parr (BLYP)38, 45, B3LYP46, Becke half‐and‐half LYP (BH&HLYP)46, long‐rang corrected BLYP(LC‐BLYP)47, and Coulomb attenuating method B3LYP (CAM‐B3LYP)48 were used as the exchange‐correlation funtionals.…”

Section: Resultsmentioning

confidence: 99%

“…This scheme, which is shown in Figure 1(b), will be examined in the following section. Of course it is needed to use the general spin orbital (GSO) version of HF or KS‐DFT for the case of noncollinear molecular magnetism39. In that case, natural orbitals using GSO‐HF/DFT solutions (GNO) should be used to yield correct localized orbitals (GLO).…”

Section: Theoretical Backgroundsmentioning

confidence: 99%

UNO‐ and ULO‐MRCC(Mk), AP‐UCC and AP‐UBD approaches to diradical systems

Nishihara

Yamanaka

Saitô

et al. 2010

Int J of Quantum Chemistry

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ABSTRACT:In this article, we performed spin-unrestricted Hartree Fock (UHF) based coupled-cluster (CC) and Bruckner CC double calculations of methylene, fluorine, HAHeAH diradical, and ozone. Mukherjee-type (Mk) Multireference coupled-cluster (MRCC) calculations of these species were also conducted by the use of UHF natural orbital (UNO) and UHF localized natural orbitals (ULO) as reference orbitals to elucidate size-consistent error. Comparing calculated results of spin-unrestricted Hartree-Fock based coupled-cluster (UCC) and spin-unrestricted Bruckner-Double (UBD) with those of MkMRCC, it was found that spin-contamination errors of UCC and UBD solutions still remained, though this type of errors for these solutions was considered to be negligible in general. The comparison also revealed scope and applicability of approximate spin-projection (AP) scheme for UCC and UBD, indicating that the AP procedure corrected spin-contamination errors to yield good agreement with MRCC in energy. We also performed pure-and hybrid-density functional theory (DFT) calculations of the same systems, and those calculations provided reasonable singlet-triplet energy gaps, which were qualitatively good agreement with those of MRCC, AP-UCC, and AP-UBD calculations. Implications of the computational results are discussed in relation to applicability of hybrid DFT to large superexchange coupled systems.

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“…Since BS-DFT does not produce the energies of the pure spin states, the expression for J must account for spin contamination. The following expressions had been suggested for this purpose [11][12][13][14]:…”

Section: Introductionmentioning

confidence: 99%

Pairwise Spin-Contamination Correction Method and DFT Study of MnH and H2 Dissociation Curves

Goel¹,

Masunov

2009

Lecture Notes in Computer Science

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Abstract.A clear advantage of broken symmetry (BS) unrestricted density functional theory DFT is qualitatively correct description of bond dissociation process, but its disadvantage is that spin-polarized Slater determinant is no longer a pure spin state (a.k.a. spin contamination). We propose a new approach to eliminate the spin-contamination, based on canonical Natural Orbitals (NO). We derive an expression to extract the energy of the pure singlet state given in terms of energy of BS DFT solution, the occupation number of the bonding NO, and the energy of the higher state built on these bonding and antibonding NOs (as opposed to self-consistent Kohn-Sham orbitals). Thus, unlike spincontamination correction schemes by Noodleman and Yamaguchi, spincorrection is introduced for each correlated electron pair individually and thus expected to give more accurate results. We validate this approach on two examples, a simple diatomic H 2 and transition metal hydride MnH.

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Generalized spin density functional theory for noncollinear molecular magnetism

Cited by 42 publications

References 43 publications

Noncollinear magnetism in density functional calculations

Noncollinear magnetism in density functional calculations

UNO‐ and ULO‐MRCC(Mk), AP‐UCC and AP‐UBD approaches to diradical systems

Pairwise Spin-Contamination Correction Method and DFT Study of MnH and H2 Dissociation Curves

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