Theoretical Methods: SCF to FCI¶
Several electronic structure methods are available in the PSI4 package, from Hartree–Fock molecular orbital theory to coupled-cluster theory to full configuration interaction. This section introduces the methods available and some of their most common input parameters. A complete list of standard keywords is provided in Appendix Keywords by Module.
- Notes on Options
- Alternate Implementations
- HF: Hartree–Fock Theory
- Introduction
- Theory
- Minimal Input
- Spin/Symmetry Treatment
- Broken Symmetry
- Orthogonalization
- Initial Guess
- Convergence Stabilization
- ERI Algorithms
- Second-order Convergence
- Stability Analysis
- Effective core potentials (ECPs)
- External potentials and QM/MM
- Convergence and Algorithm Defaults
- Recommendations
- DFT: Density Functional Theory
- DCFT: Density Cumulant Functional Theory
- DF-MP2: Density-Fitted 2nd-Order Møller–Plesset Perturbation Theory
- CC: Coupled Cluster Theory
- FNOCC: Frozen natural orbitals for CCSD(T), QCISD(T), CEPA, and MP4
- OCC: Orbital-Optimized Coupled-Cluster and Møller–Plesset Perturbation Theories
- PSIMRCC Implementation of Mk-MRCC Theory
- CI: Configuration Interaction
- SAPT: Symmetry-Adapted Perturbation Theory
- F/I-SAPT: Functional Group and/or Intramolecular SAPT
- ADC: Ab Initio Polarization Propagator
- Scalar relativistic Hamiltonians
- Geometry Optimization
- Evaluation of One-Electron Properties —
oeprop() - Vibrational and Thermochemical Analysis
