TY - GEN
T1 - Pairwise spin-contamination correction method and DFT study of MnH and H2 dissociation curves
AU - Goel, Satyender
AU - Masunov, Artëm E.
PY - 2009
Y1 - 2009
N2 - 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 spin-contamination correction schemes by Noodleman and Yamaguchi, spin-correction 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 H2 and transition metal hydride MnH.
AB - 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 spin-contamination correction schemes by Noodleman and Yamaguchi, spin-correction 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 H2 and transition metal hydride MnH.
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U2 - 10.1007/978-3-642-01973-9_16
DO - 10.1007/978-3-642-01973-9_16
M3 - Conference contribution
AN - SCOPUS:70149108088
SN - 3642019722
SN - 9783642019722
T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
SP - 141
EP - 150
BT - Computational Science - ICCS 2009 - 9th International Conference, Proceedings
T2 - 9th International Conference on Computational Science, ICCS 2009
Y2 - 25 May 2009 through 27 May 2009
ER -