|
|
|
ADF (Amsterdam Density Functional) is a Fortran program for calculations on atoms and molecules (in gas phase or solution). It can be used for the study of such diverse fields as molecular spectroscopy, organic and inorganic chemistry, crystallography and pharmacochemistry. A separate program in the ADF package (BAND) is available for the study of periodic systems: crystals, surfaces, and polymers.
The underlying theory is the Kohn-Sham approach to the Density-Functional Theory (DFT). This implies a one-electron picture of the many-electron systems but yields in principle the exact electron density (and related properties) and the total energy.
If ADF is a new program for you we recommend that you carefully read Chapter 1, section 1.2 "Technical remarks, Terminology", which presents a discussion of a few ADF-typical aspects and terminology. This will help you to understand and appreciate the output of an ADF calculation.
ADF has been developed since the early 1970s (at that time called HFS, later AMOL), mainly by the two theoretical chemistry groups of, respectively, the Vrije Universiteit in Amsterdam ( http://tc.chem.vu.nl) and the University of Calgary, Canada ( http://www.cobalt.chem.ucalgary.ca/group/master.html). Other researchers have also contributed. A recent (new) development center is the Theoretical Chemistry group at the Goningen university( http://theochem.chem.rug.nl). As a major research tool of these academic development groups ADF is in continuous development and retains a firm basis in the academic world.
Maintenance and distribution of the commercial (export) version of the program is by Scientific Computing & Modelling NV (SCM) ( http://www.scm.com), a company based in Amsterdam, formally split off from the theoretical chemistry group in Amsterdam but practically still very much a part of it.
Documentation such as User manuals, Installation instructions, Examples, Theoretical documents can be found at the SCM web site.
Publications based on research with ADF should include appropriate references to the program. We recommend that references are made both to the program itself and to publications related to its development and structure. See the "Publication Citations" document, available at the SCM web site.
ADF2000.02 is an upgrade of ADF2000.01. The "2000" indication does not imply that it is a substantially different version from the "1999" releases. Since 1999 we have adopted the convention to name each release version simply after the year of release, and to number different releases within one year by increasing the suffix. No other meaning is implied by release numbers.
In comparison to ADF1999.02, the 2000.02 release offers the following new functionality:
- QM/MM: the mixed Quantum Mechanics (QM) / Molecular Mechanics (MM) approach
to treat large systems in which only a smaller part requires accurate (QM)
treatment, while the remainder may be handled with approximate (MM) methods to
represent environment effects, steric and/or electrostatic effects, and so on.
A detailed discussion is given in the separate QMMM manual. The relevant input
keys are mentioned in this manual.
There are a few limitations regarding the
use of the QMMM functionality. The QMMM feature cannot be used with a
Frequencies run. In a Linear Transit the LT parameters must not involve any MM
atoms.
- ZORA-NMR: the NMR chemical shifts functionality in ADF1999.x is now available also in combination with the advanced ZORA relativistic approach. In many cases this yields a marked improvement over the traditional relativistic approximation in the Pauli formalism.
Furthermore, several deficiencies, bugs and inaccuracies in ADF1999 have been improved upon, more sample runs are available and the documentation has been increased for further clarification of some issues. A more extended list of "what is new or different" can be found in the Updates document.