1 / 13

Multiply Charged Ions

Multiply Charged Ions. Quantum Chemical Computations Trento, May 2002 Lecture 3. Multi-Reference Methods. Unrestricted Hartree-Fock. Multi-Configuration Self-Consistent Field (MCSCF). Bond Dissociation Multi-configuration nature E.g. O 3 TiF 3+ ( 1  + ). MR-CI(SD).

arawn
Télécharger la présentation

Multiply Charged Ions

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Multiply Charged Ions Quantum Chemical Computations Trento, May 2002 Lecture 3

  2. Multi-Reference Methods

  3. Unrestricted Hartree-Fock

  4. Multi-Configuration Self-Consistent Field (MCSCF) • Bond Dissociation • Multi-configuration nature • E.g. O3 • TiF3+ (1+)

  5. MR-CI(SD) • Only MR-CISD practical • Size inconsistent (“Davidson correction”) • MR-ACPF, MR-AQCC • CASPT2, MR-MBPT, CASMP2

  6. Excited States • CIS, TD-DFT, CCSD-EOM • MC-SCF • (Spin, symmetry)

  7. He22+ – avoided crossing

  8. Density Functional Theory Hohenberg & Kohm: E = E() E = VNN + T() + VNe() + Vee() Kohn-Sham:  = i2

  9. DFT – 2 E() = VNN + TS() + VNe() + J()+EXC() EXC() not known LDA, BP86, BLYP, GGA (PW91), B3LYP

  10. Relativity • Scalar Effects • Spin-orbit Coupling

  11. Accuracy • HF: good geometries • MP2: good geometry, energy when appropriate • DFT: good geom + energy • CCSD(T) / MR-CISD: excellent energetics where applicable

  12. Expense • HF: N4 • MP2: N5 • DFT: N3 • CCSD(T): N7 • MCSCF, MR-CISD: eN • Efficient codes for HF, MP2, DFT, CCSD(T)

  13. Programs Gaussian (98) - John Pople ACES II (R. J. Bartlett, Floride - CC methods) ADF (Amsterdam, DFT) CADPAC (Cambridge, U.K.) Columbus (I. Shavitt, Columbus, Ohio) Dalton (Norway) Gamess-USA (M. Gordon, M. Schmidt, Iowa) Gamess-UK (Daresbury, UK) Jaguar (Schrödinger, inc - R. Friesner, Portland, Oregon) MOLCAS (Lund, Suède, B. Roos) MOLPRO (P. Knowles / H.-J. Werner, UK/Allemagne) NWChem (PNL, USA) Q-Chem (Gill, Head-Gordon, Schaeffer, …) Spartan (W. Hehre, Wavefunction inc.) Turbomole (R. Ahlrichs)

More Related