3. Hamiltonians

• 3.1. Molecular Hamiltonians
  • 3.1.1. Specifying the molecular geometry
    • 3.1.1.1. Reading the molecular geometry from file
    • 3.1.1.2. Constructing a molecular geometry from scratch
  • 3.1.2. Specifying the basis set
    • 3.1.2.1. Unique basis set for all atoms
    • 3.1.2.2. Specifying different basis sets for different atoms
    • 3.1.2.3. Loading custom basis sets from file
    • 3.1.2.4. Defining basis sets with Python code
    • 3.1.2.5. Loading geometry and basis set info from one file
  • 3.1.3. Computing (Hamiltonian) matrix elements
• 3.2. Defining a model Hamiltonian
  • 3.2.1. Supported features
  • 3.2.2. The Hubbard model Hamiltonian
    • 3.2.2.1. Preliminaries
    • 3.2.2.2. Defining the Hamiltonian and boundary conditions (open or periodic)
    • 3.2.2.3. Filling the lattice
    • 3.2.2.4. Generate initial guess orbitals and overlap matrix
  • 3.2.3. Example Python script
    • 3.2.3.1. Restricted Hartree-Fock calculations using the 1-dim Hubbard model Hamiltonian with PBC
• 3.3. Dumping/Loading a Hamiltonian to/from a file
  • 3.3.1. HORTON’s internal format
    • 3.3.1.1. Dumping
    • 3.3.1.2. Loading
  • 3.3.2. FCIDUMP format
    • 3.3.2.1. Dumping
    • 3.3.2.2. Loading