4. Electronic Structure Methods

• 4.1. How to use HORTON as a Hartree-Fock/DFT program
  • 4.1.1. Setting up the (molecular electronic) Hamiltonian
  • 4.1.2. Generating an initial guess of the wavefunction
    • 4.1.2.1. Core Hamiltonian guess
    • 4.1.2.2. Randomizing an initial guess
    • 4.1.2.3. Modifying the initial guess
    • 4.1.2.4. Reading a guess from a file
    • 4.1.2.5. Projecting orbitals from a smaller basis onto a larger one
  • 4.1.3. Defining the effective Hamiltonian
    • 4.1.3.1. Supported energy terms for the effective Hamiltonians
    • 4.1.3.2. A few typical examples
  • 4.1.4. Choose an orbital occupation scheme
  • 4.1.5. Optimize the wavefunction with a self-consistent field algorithm
  • 4.1.6. Conversion of density and Fock matrix to orbitals
  • 4.1.7. Writing SCF results to a file
  • 4.1.8. Preparing for a Post-Hartree-Fock calculation
    • 4.1.8.1. Transforming the Hamiltonian to the molecular-orbital (MO) basis
    • 4.1.8.2. Reducing the Hamiltonian to an active space
  • 4.1.9. Complete examples
• 4.2. The AP1roG module
  • 4.2.1. The AP1roG model
  • 4.2.2. Currently supported features
  • 4.2.3. Input structure
    • 4.2.3.1. Getting started
    • 4.2.3.2. AP1roG with orbital optimization
    • 4.2.3.3. AP1roG without orbital optimization
  • 4.2.4. Troubleshooting in AP1roG-SCF calculations
  • 4.2.5. Example Python scripts
    • 4.2.5.1. The water molecule (a minimum input example)
    • 4.2.5.2. The water molecule (with all default keyword arguments)
    • 4.2.5.3. AP1roG with external integrals
    • 4.2.5.4. AP1roG using model Hamiltonians
• 4.3. The perturbation theory module
  • 4.3.1. Supported features
  • 4.3.2. Moller-Plesset perturbation theory of second order
    • 4.3.2.1. Getting started
    • 4.3.2.2. How to set-up an MP2 calculation
  • 4.3.3. The PTa module
    • 4.3.3.1. Getting started
    • 4.3.3.2. How to set-up a calculation
  • 4.3.4. The PTb module
    • 4.3.4.1. Getting started
    • 4.3.4.2. How to set-up a calculation
    • 4.3.4.3. Summary of keyword arguments
  • 4.3.5. Example Python scripts
    • 4.3.5.1. MP2 calculation on the water molecule
    • 4.3.5.2. PTa calculation on the water molecule
    • 4.3.5.3. PTb calculation on the water molecule