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ADF Newsletter, March 2004

Preview ADF2004

• What's new in ADF2004:
  • a. Better geometry optimizations, hybrid functionals, parallel analytic second derivatives,
    chiral optical properties, ...
  • b. Speed-ups
• ADF-Graphical User Interface: two new modules and other improvements
• Support for new hardware platforms

General news on ADF

• National ACS Spring meeting Anaheim, CA March 28-31, 2004
• ADF seminars in California, March/April 2004: Stanford, Berkeley, Scripps

General news on SCM

• SCMs new house style
• Improvements to the website (FAQ, search, archive, old documentation)
• Extension of ADF team with scientific software developer

Other news

• Article published on improved STO basis sets
• Congratulations to Myrta Grüning and Lasse Jensen on their Ph.D degrees

Preview ADF2004

What's new in ADF2004

The ADF2004.01 version is tentatively scheduled for release in the second quarter of 2004 for a number of major platforms. It will include many improvements compared to previous versions and we recommend all ADF users to switch to this version when available.

New functionality

• Improvements in grid generation: better convergence geometry optimizations
  A few important bugs have been fixed related to the generation of the numerical integration grid for
  certain types of molecular geometries. As a result, certain geometry optimizations now converge
  smoothly in 10 iterations whereas no convergence was reached in ADF2003.
• Chiral optical properties.
  Chiral optical properties were implemented by Dr. Autschbach in ADFs Time-Dependent DFT code:
  Circular Dichroism and Optical Rotatory Dispersion (CD and ORD). The implementation is fully
  parallel, can be applied to large molecules, and is very simple to use.
• Meta-GGA and hybrid xc energy functionals.
  By efficiently using ADFs fit functions, an initial beta release for a post-SCF implementation of hybrid
  functionals, such as B3LYP, will be made available. The first test results show encouraging agreement
  with literature data and the feasibility of using this option on molecules up to at least 50 atoms.
  Further improvements and speed-ups are planned. New nonempirical meta-GGA functionals have
  also been added and often outperform even the most popular hybrid functionals.
• Geometry optimizations: new Hessian update and constraint options
  New possibilities to conveniently apply nonstandard types of constraints (e.g. a linear combination of
  two constraints, or an initially unsatisfied constraint) will become available.
  New Hessian update methods have also been implemented. Both improvements have
  greatly improved geometry optimization convergence in certain, previously problematic, cases.
• Interface to NBO package:
  Dr. Autschbach, SCM, and Prof. Weinhold have collaborated to prepare a simple input file generator for
  the GENNBO program of Prof. Weinholds Natural Bond Orbital (NBO) 5.0 package:
  http://www.chem.wisc.edu/~nbo5
  This makes NBO analysis on transition and heavy metals possible with all-electron STO basis sets
  and the ZORA relativistic approach. Prof. Weinhold comments: It is really quite exciting to see
  such high-level STO/all-e/ZORA results! To those of us who were previously confined to the world
  of GTO/ECP/NR NBOs, it is a rewarding revelation to now directly see the important chemical effects
  on NBO/NRT descriptors of the ADF-enabled corrections.
  The GENNBO executable will be included in the ADF distribution and enabled via the license file
  for all those who buy an NBO manual from either the NBO authors or from SCM.
• Expectation value S²
  In ADF2004, the expectation value of S² will be printed in unrestricted calculations.
  This allows one to check the amount of spin contamination in the final result.

Speed-ups

• Faster analytic second derivatives
  The SD program for analytic second derivatives calculations has been optimized significantly.
  For medium-sized and large molecules without symmetry the new SD implementation
  (work by Dr. Wolff, Perth, Australia) should be several times faster than ADFs current finite difference
  implementation for the second derivatives.
  The speed-ups are achieved by parallelization, use of distance effects and use of symmetry.
  Other improvements to the SD code are ongoing and will be included in ADF2004.
• Parallellization NMR and CPL programs
  The NMR and CPL (for NMR spin-spin coupling constant calculations) programs have been
  parallelized. Serial bottlenecks with unfavorable scaling with system size were also removed.
  These improvements make NMR calculations on much larger molecules conveniently accessible.
  (Work by Dr. Autschbach.)
• Major speed-ups for Fock matrix calculation
  By a few subtle but important changes, the calculation of the Fock-matrix during the SCF
  has been made more efficient, saving some time for all types of calculation, especially those
  on large molecules. Usage of special compiler flags improves the situation much further
  (e.g. using SSE2 instructions for Xeon and Opteron machines). (Work by Dr. van Hees.)
• Time-dependent DFT code in BAND
  Algorithmic improvements lead to speed-ups by more than a factor of two for large TDDFT calculations
  in BAND. The speed-up becomes even more significant for systems with many atoms in the unit cell.

ADF-Graphical User Interface:
two new modules and other improvements

Improvements to modules available in ADF2003

• DENSF
  The DENSF program will be able to calculate more different types of data fields in the ADF2004
  release, such as the Electron Localisation Function (ELF). The new data fields can then be
  visualized with ADFview.
• ADFview
  Most, if not all, reported bugs were fixed. The speed of ADFview has been considerably improved,
  making rotations of the pictures much more convenient.
• ADFinput
  All reported bugs have been fixed.

New modules in ADF2004

• ADFspectra
  This module reads information from TAPE21 and displays different types of spectra that were
  calculated by ADF: Density-of-States (DOS), infrared (cf. Ethane frequency example below),
  and optical spectra (cf. optical spectrum of C60 below). One can select a peak with a mouse click.
  This will then result in additional information on that peak. In the case of an infrared spectrum,
  ADFmovie - the second new module will start up automatically to show the nuclei moving back and
  forth according to the normal mode of vibration that corresponds to the selected peak.

• ADFmovie
  This module shows moving nuclei. This is useful for visualization of molecular vibrations in
  combination with the ADFspectra module above. It can also be used (by attaching a logfile
  from a running ADF calculation) to monitor the progress of an ongoing geometry optimization.
  [Picture below shows one particular static frame of a movie for an E1u vibration
  in the ethane molecule.]

Support for new hardware platforms

The port to the HP AlphaServerSC and Fujitsu PrimePower platforms for ADF2003 has been completed. SCM is collaborating with Intel to prepare also a fast PC Linux version based on the Intel ifc compiler. This is expected to lead to very fast ADF2004 executables for Xeon and Opteron that outperform ADF2003 by a factor of two or even more. With HP, SCM is preparing a release for HP Itanium2 with HP-UX. The preliminary 1-CPU timings for ADF on this platform are currently faster than any other.

General news on ADF

National ACS Spring meeting Anaheim, CA March 28-31, 2004

SCM will be present at the upcoming national ACS meeting in Anaheim, California, 28-31 March 2004. Join the ADF booth (nr. 123) to learn more about the upcoming ADF2004 release. Contact Mr. Sunil Chawla for free expo-only vouchers to the ACS expo: http://www.scm.com/News/acs2004.html

ADF seminars in California, March/April 2004:

Stanford, Berkeley, Scripps
Dr. Stan van Gisbergen, CEO of Scientific Computing & Modelling, will give 3 seminars on ADF before and after the ACS meeting in Anaheim:

• Wednesday, March 24: Stanford University, Palo Alto, CA.
• Thursday, March 25: Berkeley University, Berkeley, CA.
• Friday, April 2: Scripps institute, La Jolla / San Diego, CA. At the Scripps seminar,
  the QM/MM implementation in ADF will also be discussed in depth.

An overview will be given of the capabilities of the upcoming ADF2004 release. There will be ample time for questions and answers. These meeting are open to scientists from outside the host institutions.

Please contact Mr. Sunil Chawla at your earliest convenience for details if you would like to attend one of these seminars.

General News on SCM

SCMs new house style

As you can see from this newsletter, from the SCM website, and from future letters you may receive, SCM has revised its house style, including logos for ADF and SCM. We trust that this new style is consistent with the professional service that we aim to offer to all ADF users.

Improvements to the website (FAQ, search, archives, old documentation)

SCM's new website has several features that make it more useful and more user-friendly, both for current ADF users and those not yet aware of ADF's capabilities:

• One can now search through the entire website by entering a keyword on the homepage
• The most recurring questions are now answered in several FAQ's, sorted by topic.
• All FAQ's are fully searchable as well.
• An archive of the ADF mailing list is constantly updated on the website. Also this archive
  is fully searchable.
• Documentation for old versions of ADF has been made available for those still making use of
  these versions.

Extension of ADF team with scientific software developer

Dr. Alexei Yakovlev will reinforce the scientific team of developers at SCM, starting April 1, 2004. Dr. Yakovlev has many years of experience in scientific programming and has been an ADF user since 1996. He mainly used ADF to study various problems in homogeneous catalysis.
This extension of the technical and scientific staff at SCM will help us implement further improvements to ADF more rapidly and serve the ADF users better than ever.

Other news

Article published on improved STO basis sets

Recently several Slater-type (STO) basis sets were tested in their performance in neutral atomic and diatomic oxide calculations. The results of these tests are given in the Journal of Computational Chemistry 24 (2003) 1142 . The tested STO basis sets are all available in the ADF package , but can also be downloaded freely.

Optimized Slater-type basis sets for the elements 1-118
E. van Lenthe and E.J. Baerends
Journal of Computational Chemistry 24 (2003) 1142.
http://www.scm.com/News/slaters.html

Congratulations to Myrta Grüning and Lasse Jensen on their Ph.D. degrees

On Nov. 7, 2003, Dr. Myrta Grüning successfully defended her Ph.D. thesis on improved xc energy functionals and potentials. A PDF file of the thesis is available from the Theses section. Contact SCM to obtain a free paper copy in book form (limited availability). http://www.scm.com/News/gruening.html

On February 13th, 2004, Dr. Lasse Jensen successfully defended his Ph.D. thesis entitled "Modelling of Optical Response Properties: Application to Nanostructures". A PDF file of the thesis is available from the Theses section of the SCM web site. Contact SCM to obtain a free paper copy in book form (limited availability).

Dr. Jensen was supervised by Prof. P.Th. van Duijnen and the late Prof. Snijders. His thesis shows results of solvent effects on linear and nonlinear optical properties of molecules. This was done with the DRF (Discrete Solvent Reaction Field) model as implemented by Dr. Jensen in a development version of ADF.
http://www.scm.com/News/jensen.html

Questions, comments, contributions

Any questions or comments regarding the above, or other questions related to ADF, are very welcome and can be sent to info@scm.com. Feel free to contact us also in case you have some information that may be of interest to other ADF users, and that may be suitable material for a future Newsletter.