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NWChem Version 4.5 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 4.5. When there is a conflict between the release notes and the User Manual, the User Manual takes precedence.

The changes for version 4.5 are listed at the bottom of this file.

Several new major capabilities are available in NWChem, including several new modules. The new modules are:

  • TCE: Tensor Contraction Engine module, that can generate unrestricted CISD, CISDT, CISDTQ, LCCD, CCD, LCCSD, CCSD, QCISD, CCSDT, CCSDTQ, MBPT(2), MBPT(3), MBPT(4) wavefunctions
  • TDDFT: time-dependent DFT, Tamm-Dancoff approximation to TDDFT, time-dependent HF, configuration-interaction singles for excited states
  • ET: Electron Transfer module that calculates the electron transfer matrix element between ET reactant and product states
  • PAW: Projector Augmented plane-Wave module
For each of these capabilities, the user is referred to the User Manual for more information.

Additional major additions to the capabilities include:

  • DFT: Added the following new functional MPW91, MPW91K, FT97, XPKBZ99 (meta-GGA)
  • SIC (Self-Interaction Correction) in the PSPW module
  • Stress calculations in the PSPW module
  • Wannier orbitals generations in the PSPW module
  • Simulated annealing for Car-Parrinello
  • Analytic hessian calculation with ECP basis sets
Again, for each of these capabilities, the user is referred to the User Manual for more information.

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: Re-introduced cc-pcvqz and its polarization functions
  • Basis set is printed if the "*" tag input is used
  • BUG FIX: Improper detection of basis libraries directory on HP Tru64
  • BUG FIX: Wrong dimension for temporary array used when detecting atom types

Geometry:

  • Added option to freeze number of orbitals in the molecule
  • BUG FIX: xyz_print is now printing angstroms instead of fractional coordinates for 3-d geometries
  • BUG FIX: z-matrix input modified to digest symbols bq"atomic symbol" x"atomic symbol" needed for DFT BSSE
  • BUG FIX: Wrong power of complex number in autosym
  • BUG FIX: When bqbq option is set the geometry was shifted a large amount

DFT:

  • New GGA density functionals: MPW91, MPW91K, FT97
  • Introduced framework for meta-GGA functional (requiring computation of the kinetic energy density tau). Coded energy term for the XPKBZ99 functional
  • BUG FIX: In the spin-orbit initial guess
  • Removed old XC grid integration scheme in used prior to nwchem 4.0
  • Introduced limited replicated-data capability in XC build; it bypasses the costly ga_acc. Activated by
    set dft:xcreplicated t
  • Performance improvements in the grid and XC build part
  • BUG FIX: Open shell HCTH (and B97-98) series of functionals did not respect alpha-beta spin symmetry
  • BUG FIX: HCTHP14 was using wrong indexing causing wrong results
  • BUG FIX: Code for grid rotational invariance now produces the correct matrix

SCF:

  • Routine to rotate movecs to a new geometry (keyword "rotate" in vectors input)

RIMP2:

  • Fortran Direct I/O have been converted to EAF calls: this allows to overcome the 2GB filesize limit

COSMO:

  • SCF and DFT interfaces made more consistent
  • Set default value of ifscr parameter to 2

Driver:

  • NEB (Nudged Elastic Band) method added (still under development)
  • ONIOM calculations can be performed with the PSPW module
  • BUG FIX: Fractional coordinates optimizer

Properties:

  • BUG FIX: GIAO integral accuracy set to 10**-15 to make more consistent cutoff strategies
  • Mulliken population analysis in full matrix output

MP2:

  • 64-bit platforms: removed 2GB file limit (this will drastically reduce the number of passes)

Analytic Hessian:

  • BUG FIX: Improved detection of conditions when analytic hessian cannot be performed (e.g. opens shell DFT, fitted-coulomb DFT)
  • Analytic hessian calculation with ECP basis sets can now performed

NBO:

  • Static memory allocation increased 6x to allow run on larger systems
  • BUG FIX: Use of OPEN(STATUS="REPLACE") (on fortran compiler that allows it) to avoid a fatal error when a file exists because a job with the same name was carried out in the same directory before
  • BUG FIX: Normalization factors for f orbitals transformation

Vib:

  • Partial canonical partition thermodynamical analysis added

PSPW:

  • CIF output changed
  • New elements added to PS library: Au Cu Fe Ge Pb Sr Ti
  • SIC (Self-Interaction Correction)
  • Band by band minimizer added
  • Wannier functions
  • Car-Parrinello: added simulated annealing strategy
  • Added Becke's ELF
  • Added calculation of stress forces

MD:

  • AMBER99: Standard parameters only as default force field
  • PME: Shifted grid approach to reduce cost of communication
  • PMF: Optional global scaling PMF force constant
  • PMF: Reporting of PMF energies
  • PMF: Specification biasing PMF for application of bias correction
  • PMF: Separate data files for each window
  • MD: Segment size used in determining pair lists
  • MD: Optional recording average properties
  • MD: Import of trajectories to re-evaluate forces and potential energies
  • MD: Use of lambda-scaling in regular MD run
  • MD: Special anisotropic pressure scaling options for membrane simulations
  • MD: Expanded timing analysis data
  • MD: Optional inclusion energies between fized atoms
  • TI: Separately reported mass-contributions to free energy differences

QM/MM:

  • Optional ESP fitting during QM/MM simulations
  • Charge of QM region specified in input
  • QM region with multiple basis set levels
  • Link atom approach using

Integrals:

  • Default value for integral internal screening threshold has been raised from 1E-15 to 1E-12 (set int:acc_std)
  • ECP: Activated 2nd derivative code
  • BUG FIX: Numerical problems in some CRENBS ecps
  • Performance improvements in Texas integrals (especially for 2nd derivatives)

DPLOT:

  • Rewrite of the code to reduce memory requirements

ESP:

  • Factor value changed from 1.45 to 1.00

General Utilities:

  • BUG FIX: Determination of how many processes are simultaneously using the scratch directory
  • Introduction of wall time remaining mechanism for LSF and PBS, activated by typing make LSF=y and make PBS=y, respectively

Installation availability:

The current tested platforms and O/S versions are:

  • IBM SP with Power 3 and Power 4 nodes, AIX 5.1 and PSSP 3.4; IBM RS6000 workstation, AIX 5.1. Xlf 8.1.0.0 and 8.1.0.1 are known to produce bad code.
  • SGI R12000 IRIX 6.5
  • SUN workstations with Solaris 2.6 and 2.8. Fujitsu SPARC systems (thanks to Herbert Fruchtl) with Parallelnavi compilers.
  • HP DEC alpha workstation , Tru64 V5.1, Compaq Fortran V5.3, V5.4.2, V5.5.1
  • Linux with Intel x86 cpus. NWChem Release 4.5 has been tested on RedHat 6.x and 7.x, Mandrake 7.x. We have tested NWChem on Linux for the Power PC Macintosh with Yellow Dog 2.4. These all use the GCC compiler at different levels. The Intel Fortran Compiler version 7 is supported. The Portland Group Compiler has been tested in a less robust manner. Automatic generation of SSE2 optimized code is available when the Intel compiler is used (ifc vs g77 performances gain of 40% in some benchmarks) A somewhat Athlon optimized code can be generated under the GNU or Intel compilers by typing "make _CPU=k7". GCC3 specific options can be turned on by typing "make GCC31=y"
  • HP 9000/800 workstations with HPUX B.11.00. f90 must be used for compilation.
  • Intel x86 with Windows 2000 has been tested with Compaq Visual Fortran 6.0 and 6.1 with WMPI 1.3 or NT-Mpich.
  • Intel IA64 under Linux (with Intel compilers) and under HPUX
  • Fujitsu VPP computers


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Updated: March 8, 2005