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 NWChem Version 4.6 Notes
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 4.6. When there is a conflict between the release notes and the
User Manual, the User Manual takes precedence.
 
The changes for version 4.6 are listed at the bottom of this file.
 
Several new major capabilities are available in NWChem, including several new modules. The new modules are: 
  For each of these capabilities, the user is referred to the
User Manual for more information.CCSD(T) and CCSD[T] for closed- and open-shell systems with Abelian symmetry
      (contributed by Alex Auer, University of Waterloo)EOM-CCSD, EOM-CCSDT, EOM-CCSDTQ for excitation energies, transition moments, and excited-state dipole moments of closed- and open-shell
      systemsCCSD, CCSDT, CCSDTQ for dipole moments of closed- and open-shell
      systemsConstraints module that is capable of freezing atom positions and restraining bond
      lengths during optimization. 
 Additional major additions to the capabilities include:
  Again, for each of these capabilities, the user is referred to the
User Manual for more information.van Leeuwen-Baerends potential for DFT and TDDFTCasida-Salahub asympototic correction for DFT and TDDFTA new self-contained asymptotic correction for B3LYP DFT and TDDFTA new density functional TPSS, energy term onlyAdded the functional HCTH/407+A new keyword in TCE to allow/suppress the recomputation of the Fock
      matrix.  This is useful for one-component relativistic CI/CC/MBPT/EOM-CCTwo new I/O algorithms (DRA and GA+EAF) in TCE.QHOP proton hopping method in MDCharmm force field (Urey-Bradley) 
Listed below are the other 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.
 
 
 Basis Sets:
  BUG FIX: Iodine Stuttgart Large Core ECP to conform to the one published by Bergner et. al. (Mol. Phys. 1993)Definition of PERMANENT_DEF_DIR, SCRATCH_DEF_DIR NWCHEM_BASIS_LIBRARY_PATH at compile time is gone. These
      environmental variables will be ignored. Compilation automatically stops if the NWCHEM_TOP name is longer than 65 chars. 
 
 BLAS:
  Introduce faster dgemm (with more aggressive blocking) 
 
 CCSD(T):
  Improved memory allocationBUG FIX: TOL2E convergence parameter is now properly handled 
 
 COSMO:
  BUG FIX: Mass was used for radius in ECP calculations. 
 
 DFT:
  Better handling of exponential underflow speeds up certain platforms.Implemented GA mirroring to address network latency issues (activated by set dft:xcreplicated t)Speed improvement by introducing more aggressive screening for basis functions evaluations and grid partitioning weightsAdded pstat profilingIn-core coulomb algorithm: improved outputXC grid restructuring for getting fault-tolerance in gradients; added "grid nodisk" keyword for skipping I/O operation for grid
  Increased limit for grid sizeBUG FIX: The final vectors are now printed when requestedBUG FIX: Bq atoms with different charges are no longer considered to be different atom typesBUG FIX: Fix associated with VWN functional exceptionBUG FIX: d4d group was causing loss of weights normalization 
 
 Geometry:
  BUG FIX: Geometries containing bqs were causing the autosym module to crashBUG FIX: Autosym was not correctly detecting the degeneracy of the moments of inertia 
 
 Hessian:
  BUG FIX: Fixes associated with linear dependencies.CPHF SCF residual error termination is now set to 1d-2 (was 1d-4) 
 
 Input:
  Default memory increased from 200 mb to 400 mb 
 
 Integrals:
  Performances improvements in the McMurchie-Davidson algorithmBUG FIX: Increased limpair value to address "getmem memory overflow" problem 
 
 MD:
   Molecule-based periodic boundary conditions Revised file formats for frg, sgm and top files Radius of gyration and diffusion coefficient are optional properties Reduced memory allocation for work arrays Prefetching using non-blocking communication Option to aid in membrane setup Trajectories recorded in multiple files Redesign cell-cell list to avoid most common 'lbbl errors' Multiple parameter databases Mixed parameter definitions Improved performance in prepare module for very large systems 
 
 MP2:
  Added scratchdisk keyword to limit disk usage on a per process base 
 
 NBO:
  BUG FIX: Title writing turned off since requires risky character to integer conversion that breaks many compilersBUG FIX: Intel compiler 8.0 was crashing on Hollerith characters 
 
 Numerical gradient:
  BUG FIX: Atoms list was corrupted when symmetry is on 
 
 NWPW:
  Pseudoptential library: NWCHEM_NWPW_LIBRARY_PATH is gone in a similar fashion to what happened to Gaussian basis
      library. Compilation automatically stops if the NWCHEM_TOP name is longer than 65 chars.BUG FIX: ELF generation in pspw_dplot fixed.Mulliken projection now uses pseudoatomic orbitalsAutomatic grid conversionPreliminary version of HGH pseudopotentialsPSPW: virtual orbital calculationsCar-Parrinello: geometry constraintsBAND: Monkhorst-Pack k-point generationBAND: LMBFGS minimizerPAW: free space boundary conditionsPerformances improvements in the non-local pseudopotential and orthogonalility calculations 
 
 Properties:
  Ecce support added for NMR properties 
 
 QMD:
  Released restriction on theory type that can be used in the computation. 
 
 Rtdb:
  Added option to store rtdb in memory (-DDB_INMEM). This option creates a dummy .db file, therefore restart will not work. 
 
 SELCI:
  Now runs on 64 bit platforms 
 
 SCF:
  BUG FIX: Linear dependency is accounted for in vector projections.BUG FIX: Vectors "lock" was causing hang-ups in certain parallel runs.BUG FIX: Got rid of hard-wired limit of 10,000 basis functions. 
 
 TDDFT:
  BUG FIX: Fixed S**2 expectation value when frozen core is used 
 
 Util:
  BUG FIX: Made the interface to LSF to estimate wall-time remaining more fault-tolerantI/O on system with inhomogeneous disk sizes is made more robust 
 
 New Platform added:
  Mac OSX 10.3 with GNU (gcc and g77 3.4) and IBM (xlf) compilersCray X1Opteron Linux with GNU, Portland Group and PathScale compilers.Linux ppc64 with IBM compilersINTERIX platform using the Windows Services For Unix (http://www.microsoft.com/windows/sfu/default.asp) 
 
 New compiler support:
  Intel fortran compiler version 8.0 for IA32 and IA64Use of g77 version 3.3 (3.3.1, 3.3.2 and 3.3.3) is supported, but not recommended. We had to put in place version fix for this
      compiler (e.g. http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13037) g77 3.1.x 3.2.x and 3.4 are known to work 
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 Contact: NWChem Support
 Updated: March 8, 2005
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