Input file changes:
New keyword METHOD simplifies input in most cases by replacing the pair of keywords EXCHANGE and CORRELATION (see Chapter 4).
Keywords for requesting excited-state calculations have been modified and simplified (see Chapter 7 for details).
Keywords for solvation models have been modified and simplified (see Section 11.2 for details).
New features for NMR calculations including spin-spin couplings (J. Kussmann, A. Luenser, and C. Ochsenfeld; Section 10.12.1).
New built-in basis sets (see Chapter 8).
New features and performance improvements in EOM-CC:
EOM-CC methods extended to treat meta-stable electronic states (resonances) via complex scaling and complex absorbing potentials (D. Zuev, T.-C. Jagau, Y. Shao, and A. I. Krylov; Section 7.10.8).
New features added to EOM-CC iterative solvers, such as methods for interior eigenvalues and user-specified guesses (D. Zuev; Section 7.10.16).
Multi-threaded parallel code for (EOM-)CC gradients and improved CCSD(T) performance.
SM12 implicit solvation model (A. V. Marenich, D. G. Truhlar, and Y. Shao; Section 18.104.22.168).
Interface to NBO v. 6 (Section 10.3).
Optimization of MECPs between electronic states at the SOS-CIS(D) and TDDFT levels (X. Zhang and J. M. Herbert; Section 9.8.3).
ROKS method for SCF calculations of excited states (T. Kowalczyk and T. Van Voorhis; Section 7.8.1).
Fragment-based initial guess for SCF methods (Section 12.3).
Pseudo-fractional occupation number method for improved SCF convergence in small-gap systems (D. S. Lambrecht; Section 4.5.6).
Density embedding scheme (B. J. Albrecht, E. Berquist, and D. S. Lambrecht; Section 11.6).
New features and enhancements in fragment-based many-body expansion methods (K. U. Lao and J. M. Herbert):
Periodic boundary conditions with proper Ewald summation, for energies only (Z. C. Holden and J. M. Herbert; Section 11.3).