Gaussian 16 also offers a wide variety of performance improvements to many different parts of the program. Among the most significant are the following:

  • Support for NVIDIA K40 and K80 GPUs on Linux systems, for HF and DFT calculations.
  • Speedups for key parts of several calculation types.
  • CASSCF improvements and support for active spaces of up to 16 orbitals.
  • An optimized memory algorithm which avoid I/O during CCSD iterations.
  • Enhancements to GEDIIS optimization algorithm.
  • CASSCF improvements for calculations using active spaces larger than (10,10). Active spaces of (16,16) can noe be feasible (depending on the system).
  • Faster performance for the low level part of the OVGF compound model for predicting photoelectron spectra.
  • For example, a DFT Opt=CalcFC Freq calculation on Alanine 254 is 1.8 times faster in Gaussian 16 than in Gaussian 09. The two second derivative calculations for this job comprise 47% of the execution time in Gaussian 16 compared to 61% in Gaussian 09.