<Modeling Capabilities> - TD-DFT analytic second derivatives for predicting vibrational frequencies/IR and Raman spectra and performing transition state optimizations and IRC calculations for excited states. - EOMCC analytic gradients for performing geometry optimizations. - Anharmonic vibrational analysis for VCD and ROA spectra. - Vibronic spectra and intensities. - Resonance Raman spectra. - New DFT functionals: M08HX, MN15, MN15L. - New double-hybrid methods: DSDPBEP86, PBE0DH and PBEQIDH. - PM7 semi-empirical method. - Ciofini excited state charge transfer diagnostic. - The EOMCC solvation interaction models of Caricato. - Generalized internal coordinates, a facility which allows arbitrary redundant internal coordinates to be defined and used for optimization constraints and other purposes.
<Performance Enhancements> - NVIDIA K40 and K80 GPUs are supported under Linux for Hartree-Fock and DFT calculations. - Parallel performance on larger numbers of processors has been improved. See the Parallel Performance tab for information about how to get optimal performance on multiple CPUs and clusters. - Gaussian 16 uses an optimized memory algorithm to avoid I/O during CCSD iterations. - There are several enhancements to the GEDIIS optimization algorithm. - CASSCF improvements for active spaces > (10,10) increase performance and make active spaces of up to 16 orbitals feasible (depending on the molecular system). - Significant speedup of the core correlation energies for W1 compound model. - Gaussian 16 incorporates algorithmic improvements for significant speedup of the diagonal, second-order self-energy approximation (D2) component of composite electron propagator (CEP) methods as described in [DiazTinoco16].
<Usage Enhancements> - Tools for interfacing Gaussian with other programs, both in compiled languages such as Fortran and C and with interpreted languages such as Python and Perl. - Parameters specified in Link 0 (%) input lines and/or in a Default.Route file can now also be specified via either command-line arguments or environment variables. - Compute the force constants are every nth step of a geometry optimization.