NWChem Version 5.1 Release Notes
(Also available at 
http://www.emsl.pnl.gov/docs/nwchem/release-notes/release.notes.5.1.html)

NOTE: These release notes are not a substitute for reading the User Manual!

They are meant to give a thumbnail sketch of the new capabilities and bug
fixes that are available in NWChem Version 5.1. When there is a conflict
between the release notes and the User Manual, the User Manual takes
precedence. 

Several new major capabilities are available in NWChem:
  o New spin-orbit zeroth-order relativistic approximation (ZORA) for Gaussian 
    and plane wave DFT 
  o Constrained DFT (CDFT)
  o Fermi smearing to model metals in plane wave DFT
  o Car-Parrinello QM/MM added to plane wave DFT
  o 
  o Coupled-cluster linear response available using both restricted and 
    unrestricted references
  o Ground-state dynamic polarizabilities at the coupled-cluster singles, 
    doubles, and triples levels of theory
  o Second order approximate coupled-cluster model with singles and
    doubles (CC2) for excited states in TCE 
  o 
 
Listed below are the major and many minor changes for each module
with significant changes. These descriptions are somewhat terse and more
information is generally available in the User Manual. 

DFT:
  o Spin-free and spin-orbit zeroth-order relativistic approximation (ZORA) 
  o Constrained DFT (CDFT)

NWPW:
  o Fermi smearing added to BAND
  o Two-component wavefunctions added to BAND
  o HGH spin-orbit potentials added to BAND
  o Hilbert decomposed parallel FFT added to BAND
  o Car-Parrinello QM/MM added to PSPW
  o Wannier orbital generation now works with non-cubic cells
  o New parallel decomposition in which both the FFT grid and orbitals are
    distributed has been implemented in PSPW

TCE:
  o New variants of 4-index transformation
  o CC2 - second order approximate coupled-cluster model with singles and 
    doubles(for excited-state calculations)
  o locally renormalized EOMCCSD approach
  o Memory efficient version of CR-EOMCCSD(T) formalism

Properties:
  o Coupled-cluster linear response available using both restricted
    (RHF/ROHF) and unrestricted (UHF/KS) references 
  o Ground-state dynamic polarizabilities at the CCSD and CCSDT levels of
    theory using the linear response formalism

A general FAQ is available at
http://www.emsl.pnl.gov/docs/nwchem/support/faq/NWChem_FAQ.html
