Gaussian 09 Features at a Glance

Features added since the initial release of Gaussian 03 are in scarlet.

Each section lists all relevant features; there is sometimes overlap between sections.

Fundamental Algorithms

• Calculation of 1- & 2-electron integrals over any contracted gaussian functions
• Conventional, direct, semi-direct and in-core algorithms
• Linearized computational cost via automated fast multipole methods (FMM) and sparse matrix techniques
• Network/cluster and shared memory (SMP) parallelism
• Harris initial guess (much more accurate, especially for metals)
• Initial guess generated from fragment guesses or fragment SCF solutions
• Density fitting and Coulomb engine for pure DFT calculations, including automated generation of fitting basis sets
• O(N) exact exchange for HF and hybrid DFT
• 1D, 2D, 3D periodic boundary conditions (PBC) energies & gradients (HF & DFT)

Model Chemistries

Molecular Mechanics: Amber, DREIDING and UFF energies, gradients, and frequencies; standalone MM program; custom force fields

Ground State Semi-Empirical

• CNDO/2, INDO, MINDO3 and MNDO energies and gradients
• Newly implemented AM1, PM3, PM3MM, PM6 and PDDG energies, gradients and analytic freqs., with custom parameters
• DFTB and DFTBA methods

Self Consistent Field (SCF)

• SCF restricted and unrestricted energies, gradients and frequencies, and RO energies and gradients
• Default EDIIS+CDIIS convergence algorithm and optional Quadratic Convergent SCF
• Complete Active Space SCF (CASSCF) energies, gradients & frequencies; active spaces of up to 14 orbitals (8 for freqs.)
• Restricted Active Space SCF (RASSCF) energies and gradients
• Generalized Valence Bond-Perfect Pairing energies and gradients
• Wavefunction stability analysis (HF & DFT)

Density Functional Theory

Closed shell and open shell energies, gradients & frequencies, and RO energies & gradients are available for all DFT methods.

• exchange functionals: Slater, Xa, Becke 88, Perdew-Wang 91, Barone-modified PW91, Gill 96, OPTX, TPSS, BRx, PKZB, wPBEh, PBEh
• correlation functionals: VWN, VWN5, LYP, Perdew 81, Perdew 86, Perdew-Wang 91, PBE, B95, TPSS, KCIS, BRC, PKZB
• other pure functionals: VSXC, HCTH functional family
• hybrid methods: B3LYP, B3P86, P3PW91, B1 and variations, B98, B97-1, B97-2, PBE1PBE, HSEH1PBE and variations, O3LYP, TPSSh, BMK, M05 & M06 and variations, X3LYP; user-configurable hybrid methods
• empirical dispersion: B97D
• long range-corrected: LC-wPBE, CAM-B3LYP, WB97XD and variations, Hirao’s general LC correction

Electron Correlation:

All methods/job types are available for both closed and open shell systems and may optionally use frozen core orbitals; restricted open shell calculations are available for MP2, MP3, MP4 and CCSD/CCSD(T) energies.

• MP2 energies, gradients, and frequencies
• B2PLYP and MPW2PLYP double hybrid DFT energies, gradients and frequencies, with optional empirical dispersion
• CASSCF calculations with MP2 correlation for any specified set of states
• MP3 and MP4(SDQ) energies and gradients
• MP4(SDTQ) and MP5 energies
• Configuration Interaction (CISD) energies & gradients
• Quadratic CI energies & gradients; QCISD(TQ) energies
• Coupled Cluster methods: restartable CCD, CCSD energies & gradients, CCSD(T) energies; optionally input amplitudes computed with smaller basis set
• Brueckner Doubles (BD) energies and gradients, BD(T) energies; optionally input amplitudes & orbitals computed with a smaller basis set
• Enhanced Outer Valence Green’s Function (OVGF) methods for ionization potentials & electron affinities
• Complete Basis Set (CBS) MP2 Extrapolation
• Douglas-Kroll-Hess scalar relativistic Hamiltonians

Automated High Accuracy Energies

• G1, G2, G3, G4 and variations
• CBS-4, CBS-q, CBS-QB3, ROCBS-QB3, CBS-Q, CBS-APNO
• W1U, W1BD, W1RO

Basis Sets and DFT Fitting Sets

• STO-3G, 3-21G, ..., 6-31G, 6-31G†, 6-311G, D95, D95V, SHC, LanL2DZ, cc-pV{D,T,Q,5,6}Z, Dcc-p{D,T}Z, SV, SVP, TZV, QZVP, EPR-II, EPR-III, Midi!, UGBS*, MTSmall, DG{D,T}ZVP
• Effective Core Potentials (through second derivatives): LanL2DZ, CEP through Rn, Stuttgart/Dresden
• Support for basis functions and ECPs of arbitrary angular momentum
• dft fitting sets: DGA1, DGA1, W06; auto-generated fitting sets; optional default enabling of density fitting

Geometry Optimizations
and Reaction Modeling

• Geometry optimizations for equilibrium structures, transition structures, and higher saddle points, in redundant internal, internal (Z-matrix), Cartesian, or mixed internal and Cartesian coordinates
• Redundant internal coordinate algorithm designed for large system, semi-empirical optimizations
• Newton-Raphson and Synchronous Transit-Guided Quasi-Newton (QST2/3) methods for locating transition structures
• IRCMax transition structure searches
• Relaxed and unrelaxed potential energy surface scans
• New implementation of intrinsic reaction path following (IRC), applicable to ONIOM QM:MM with thousands of atoms
• Reaction path optimization
• BOMD molecular dynamics (all analytic gradient methods); ADMP molecular dynamics: HF, DFT, ONIOM(MO:MM)
• Optimization of conical intersections via state-averaged CASSCF

Vibrational Analysis

• Vibrational frequencies and normal modes, including display/output limiting to specified atoms/residues/modes (optional mode sorting)
• Restartable analytic HF and DFT freqs.
• MO:MM ONIOM frequencies including electronic embedding
• Analytic Infrared and static and dynamic Raman intensities (HF & DFT; MP2 for IR)
• Pre-resonance Raman spectra (HF and DFT)
• Projected frequencies perpendicular to a reaction path
• NMR shielding tensors & GIAO magnetic susceptibilities (HF, DFT, MP2) and enhanced spin-spin coupling (HF, DFT)
• Vibrational circular dichroism (VCD) rotational strengths (HF and DFT)
• Dynamic Raman Optical Activity (ROA) intensities
• Harmonic vibration-rotation coupling
• Enhanced anharmonic vibrational analysis
• Anharmonic vibration-rotation coupling via perturbation theory
• Hindered rotor analysis

Molecular Properties

• Electronic circular dichroism (ECD) rotational strengths (HF and DFT)
• Electrostatic potential, electron density, density gradient, Laplacian, and magnetic shielding & induced current densities over an automatically generated grid
• Multipole moments through hexadecapole
• Population analysis, including per-orbital analysis for specified orbitals
• Biorthogonalization of molecular orbitals (producing corresponding orbitals)
• Electrostatic potential-derived charges
• Natural orbital analysis and natural transition orbitals
• Natural Bond Orbital (NBO) analysis, including orbitals for CAS jobs
• Electrostatic energy & Fermi contact terms
• Static and frequency-dependent analytic polarizabilities and hyperpolarizabilities (HF and DFT); numeric 2nd hyperpolar-izabilities (HF; DFT w/ analytic 3rd derivs.)
• Approx. CAS spin orbit coupling between states
• Enhanced optical rotations and optical rotary dispersion (ORD)
• Hyperfine spectra components: electronic g tensors, Fermi contact terms, anisotropic Fermi contact terms, rotational constants, dipole hyperfine terms, quartic centrifugal distortion, electronic spin rotation tensors, nuclear electric quadrupole constants, nuclear spin rotation tensors
• Franck-Condon analysis (photoionization)
• ONIOM integration of electric and magnetic properties

ONIOM Calculations

• Enhanced 2 and 3 layer ONIOM energies, gradients and frequencies using any available method for any layer
• Optional electronic embedding for MO:MM energies, gradients and frequencies
• Enhanced MO:MM ONIOM optimizations to minima and transition structures via microiterations including electronic embedding
• Support for IRC calculations
• ONIOM integration of electric and magnetic properties

Excited States

• ZINDO energies
• CI-Singles energies, gradients, & freqs.
• Restartable time-dep. HF & DFT energies and gradients
• SAC-CI energies and gradients
• EOM-CCSD energies (restartable); optionally input amplitudes computed with a smaller basis set
• Franck-Condon, Herzberg-Teller and FCHT analyses
• CI-Singles and TD-DFT in solution
• State-specific excitations and de-excitations in solution

Self-Consistent Reaction
Field Solvation Models

• New implementation of the Polarized Continuum Model (PCM) facility for energies, gradients and frequencies
• Solvent effects on vibrational spectra, NMR, and other properties
• Solvent effects for ADMP trajectory calcs.
• Solvent effects for ONIOM calculations
• Enhanced solvent effects for excited states
• SMD model for ΔG of solvation
• Other SCRF solvent models (HF & DFT): Onsager energies, gradients and freqs., Isodensity Surface PCM (I-PCM) energies and Self-Consistent Isodensity Surface PCM (SCI-PCM) energies and gradients

Ease-of-Use Features

• Automated counterpoise calculations
• Automated optimization followed by frequency or single point energy
• Ability to easily add, remove, freeze, differentiate redundant internal coords.
• Simplified isotope substitution and temperature/pressure specification in the route section
• Freezing by fragment for ONIOM optimizations
• Simplified fragment definitions on molecule specifications
• Many more restartable job types
• Atom freezing in optimizations by type, fragment, ONIOM layer and/or residue
• QST2/QST3 automated transition structure optimizations
• Saving and reading normal modes