2. Essential Calculation Elements

Essential Calculation Elements

• 2.1. General Structure of the Input File
  • 2.1.1. Input Blocks
  • 2.1.2. Input Priority and Processing Order
  • 2.1.3. Global Memory Use
  • 2.1.4. Changing the Default BaseName
  • 2.1.5. Jobs with Multiple Steps
  • 2.1.6. List of Input Blocks
  • 2.1.7. Simple Keyword Lines
• 2.2. Input of Coordinates
  • 2.2.1. Reading coordinates from the input file
  • 2.2.2. Reading coordinates from external files
  • 2.2.3. Special definitions
  • 2.2.4. Defining Geometry Parameters and Scanning Potential Energy Surfaces
  • 2.2.5. Mixing internal and Cartesian coordinates
  • 2.2.6. Inclusion of Point Charges
• 2.3. Basic Calculation Settings
  • 2.3.1. Run Types
  • 2.3.2. Method Classes
  • 2.3.3. Keywords
• 2.4. Control of Output
  • 2.4.1. Print Options
  • 2.4.2. Simple Input Keywords
• 2.5. Parallel and Multi-Process Runs
  • 2.5.1. Parallel and Multi-Process Modules
    • 2.5.1.1. List of Parallelized Modules
    • 2.5.1.2. List of Multi-Process Modules
  • 2.5.2. Hints on the Use of Parallel ORCA
    • 2.5.2.1. Single Node Runs
    • 2.5.2.2. Multi-Node Runs - Remote Execution
    • 2.5.2.3. Multi-Process Calculations
• 2.6. Self-Consistent-Field (SCF)
  • 2.6.1. Convergence Tolerances
  • 2.6.2. Dynamic and Static Damping
  • 2.6.3. Level Shifting
  • 2.6.4. Direct Inversion in Iterative Subspace (DIIS)
  • 2.6.5. Kolmar’s DIIS (KDIIS)
  • 2.6.6. Approximate Second Order SCF (SOSCF)
  • 2.6.7. Trust-Region Augmented Hessian (TRAH) SCF
    • 2.6.7.1. When to Use TRAH
      • 2.6.7.1.1. AutoTRAH
    • 2.6.7.2. Theoretical Basis
    • 2.6.7.3. Performance and Implementation Details
    • 2.6.7.4. Input Parameters
    • 2.6.7.5. Practical Notes
    • 2.6.7.6. Example Case
  • 2.6.8. Finite Temperature SCF
    • 2.6.8.1. Fractional Occupation Numbers
  • 2.6.9. Tips and Tricks: Converging SCF Calculations
  • 2.6.10. Local-SCF Method
  • 2.6.11. Keywords
• 2.7. Basis Sets
  • 2.7.1. Basic Usage
  • 2.7.2. Orbital Basis Sets
    • 2.7.2.1. Pople Basis Sets
    • 2.7.2.2. Ahlrichs Basis Sets
    • 2.7.2.3. Karlsruhe def2 Basis Sets
    • 2.7.2.4. Karlsruhe dhf Basis Sets
    • 2.7.2.5. Jensen Basis Sets
    • 2.7.2.6. Hydrogenic Gaussian Basis Sets
    • 2.7.2.7. Sapporo Basis Sets
    • 2.7.2.8. Partridge Basis Sets
    • 2.7.2.9. CRENB Basis Sets
    • 2.7.2.10. LANL Basis Sets
    • 2.7.2.11. Correlation-consistent Basis Sets
    • 2.7.2.12. F12 Basis Sets
    • 2.7.2.13. Atomic Natural Orbital Basis Sets
      • 2.7.2.13.1. Efficient Calculations with ANO Basis Sets
    • 2.7.2.14. Miscellaneous and Specialized Basis Sets
  • 2.7.3. Relativistic Basis Sets
    • 2.7.3.1. Recontracted Ahlrichs Basis Sets
    • 2.7.3.2. Recontracted Karlsruhe def2 Basis Sets
    • 2.7.3.3. SARC Basis Sets
    • 2.7.3.4. SARC2 Basis Sets
    • 2.7.3.5. Karlsruhe x2c Basis Sets
    • 2.7.3.6. Relativistic Sapporo Basis Sets
    • 2.7.3.7. Relativistic Correlation-Consistent Basis Sets
    • 2.7.3.8. Relativistically Contracted ANO Basis Sets
  • 2.7.4. Auxiliary Basis Sets
    • 2.7.4.1. Coulomb-fitting auxiliary basis sets (AuxJ)
    • 2.7.4.2. Coulomb- and exchange-fitting auxiliary basis sets (AuxJK)
    • 2.7.4.3. Auxiliary basis sets for correlated methods (AuxC)
    • 2.7.4.4. Complementary auxiliary basis sets for F12 (CABS)
    • 2.7.4.5. Automatic Generation of Auxiliary Basis Sets (AutoAux)
  • 2.7.5. Effective Core Potentials
    • 2.7.5.1. Manual Input of ECP Parameters
    • 2.7.5.2. ECPs and Ghost Atoms
    • 2.7.5.3. ECP Embedding
  • 2.7.6. Assigning or Adding Basis Functions to an Element
  • 2.7.7. Assigning or Adding Basis Functions to Individual Atoms
  • 2.7.8. Assigning Basis Sets and ECPs to Fragments
  • 2.7.9. Reading Basis Sets from a File
  • 2.7.10. Linear Dependence
    • 2.7.10.1. Automatic Adjustments for Near Linear-Dependent Cases
    • 2.7.10.2. Removal of Redundant Basis Functions
  • 2.7.11. Which Methods Need Which Basis Sets?
  • 2.7.12. Keywords
• 2.8. Resolution-of-the-Identity (RI)
  • 2.8.1. RI-J
  • 2.8.2. Split-RI-J
  • 2.8.3. RIJONX
  • 2.8.4. RIJCOSX
    • 2.8.4.1. Basic Usage
    • 2.8.4.2. RIJCOSX Gradient
    • 2.8.4.3. COSX Numerical Grids
    • 2.8.4.4. SFitting Parameters
    • 2.8.4.5. Partial Contraction Scheme
    • 2.8.4.6. Restoring Full Symmetry
    • 2.8.4.7. COSX Grid and Convergence Issues
  • 2.8.5. RI-JK
    • 2.8.5.1. Basic Usage
  • 2.8.6. Speed Comparison of RIJCOSX and RI-JK
  • 2.8.7. Keywords
• 2.9. Numerical Integration
• 2.10. Details on the Numerical Integration Grids
  • 2.10.1. The Angular Grid Scheme
  • 2.10.2. The Radial Grid Scheme
  • 2.10.3. The DEFGRIDs
  • 2.10.4. Other Details and Options
  • 2.10.5. SCF Grid Keyword List
  • 2.10.6. Changing TD-DFT, CP-SCF and Hessian Grids
  • 2.10.7. When to Change from the Default Grids?
• 2.11. Counterpoise Corrections
  • 2.11.1. Boys-Bernardi Counterpoise Correction (BB-CP)
  • 2.11.2. Geometrical Counterpoise Correction (gCP)
    • 2.11.2.1. Basic Usage
    • 2.11.2.2. Keywords
• 2.12. Relativistic Calculations
  • 2.12.1. Basic Usage
    • 2.12.1.1. Scalar-Relativistic Gradients and Properties
  • 2.12.2. Approximate Relativistic Hamiltonians
    • 2.12.2.1. One-Center Approximation
  • 2.12.3. The Regular Approximation
    • 2.12.3.1. The Scaled ZORA Variant
    • 2.12.3.2. The Regular Approximation with Model Potential
  • 2.12.4. The Douglas-Kroll-Hess Method
    • 2.12.4.1. Magnetic Properties with DKH
  • 2.12.5. Exact Two-Component Theory (X2C)
    • 2.12.5.1. DLU Approximation
    • 2.12.5.2. X2C Derivatives and Properties
  • 2.12.6. Basis Sets in Relativistic Calculations
  • 2.12.7. Picture-Change Effects
  • 2.12.8. Finite Nucleus Model
  • 2.12.9. Keywords
• 2.13. Implicit Solvation
  • 2.13.1. The Conductor-like Polarizable Continuum Model (C-PCM)
    • 2.13.1.1. Use of the Gaussian Charge Scheme
    • 2.13.1.2. Use of the Point Charge Scheme
    • 2.13.1.3. Calculation of the free energy of solvation within the C-PCM
    • 2.13.1.4. Options for Computing the CPCM terms
  • 2.13.2. The Conductor-like Screening Solvation Model (COSMO)
  • 2.13.3. The SMD Solvation Model
  • 2.13.4. Dynamic Radii Adjustment for Continuum Solvation (DRACO)
  • 2.13.5. OpenCOSMO-RS
    • 2.13.5.1. How to Run a ORCA/COSMO-RS Calculation
    • 2.13.5.2. OpenCOSMO-RS Keywords
  • 2.13.6. Implicit Solvation in Coupled-Cluster Methods
    • 2.13.6.1. PTE scheme
    • 2.13.6.2. PTE(S) scheme
    • 2.13.6.3. PTES scheme
  • 2.13.7. Complete Keyword List for the %cpcm Block
• 2.14. Integral Handling
  • 2.14.1. Compression and Storage
  • 2.14.2. Distance Dependent Pre-Screening
  • 2.14.3. The “BubblePole” Approximation
  • 2.14.4. Angular Momentum Limits
  • 2.14.5. Keywords
• 2.15. The SHARK Integral Package and Task Driver
  • 2.15.1. Preface
  • 2.15.2. The SHARK integral algorithm
  • 2.15.3. SHARK and libint
  • 2.15.4. Basis set types
  • 2.15.5. Task drivers
  • 2.15.6. SHARK User Interface
• 2.16. SCF Stability Analysis
• 2.17. Finite Electric Fields
  • 2.17.1. Dipolar Electric Fields
  • 2.17.2. Quadrupolar Electric Fields
  • 2.17.3. Combination of Dipolar and Quadrupolar Electric Fields
  • 2.17.4. Keywords
• 2.18. Fragment Specification
  • 2.18.1. Fragments defined on Input File
  • 2.18.2. Automatic Fragmentation
    • 2.18.2.1. Automatic Fragmentation: Connectivity
    • 2.18.2.2. Automatic Fragmentation: Atomic and NotAssigned
    • 2.18.2.3. Automatic Fragmentation: Internal Libraries
    • 2.18.2.4. Automatic Fragmentation: External Libraries
    • 2.18.2.5. Automatic Fragmentation: Extend
    • 2.18.2.6. Automatic Fragmentation: Fusebyatoms
    • 2.18.2.7. Automatic Fragmentation: Delete and advanced fragmentation workflows
  • 2.18.3. Options available in the %frag input block
• 2.19. ORCA and Symmetry
  • 2.19.1. Getting started
  • 2.19.2. Geometry optimizations using symmetry
  • 2.19.3. Diagonalization of the geometric Hessian using symmetry
  • 2.19.4. Default alignment of the symmetry elements with the coordinate system
  • 2.19.5. Irreducible representations of \(D_{2h}\) and subgroups
  • 2.19.6. Options available in the %Symmetry input block
• 2.20. Choice of Initial Guess and Restart of SCF Calculations
  • 2.20.1. One Electron Matrix Guess
  • 2.20.2. Basis Set Projection
  • 2.20.3. PModel Guess
  • 2.20.4. Hückel and PAtom Guesses
  • 2.20.5. Restarting SCF Calculations
  • 2.20.6. AutoStart feature
  • 2.20.7. Changing the Order of Initial Guess MOs and Breaking the Initial Guess Symmetry
  • 2.20.8. Automatically Breaking of the Initial Guess Symmetry
  • 2.20.9. Calculating only the energy of an input density
  • 2.20.10. Keywords
• 2.21. Frozen Core Options
• 2.22. CP-SCF Options
• 2.23. Numerical Gradients