Performance, Precision, Technical

The energy decomposition in a single-point run (and at the end of an optimization) and the energy calculation during optimization / Linear Transit / ... runs were not exactly identical in version 2.3, with discrepancies in the order of 0.01eV. Analysis revealed that a different handling of fit-related inaccuracies caused the difference and that, in fact, a slightly more accurate correction for the fit-error could be used in either case. Both algorithms have accordingly been improved and now give the same results.

Differences with ADF2.3 results (regarding this aspect) should be fairly small: 0.01eV or less. They may be larger when rather inaccurate fit sets are used.

Single-Point runs with single-atom fragments that were computed in ATOM symmetry now also use exact rather than fit densities for the computation of the electrostatic interaction between the fragments. This eliminates any fit-related error from that energy term.

The parallel execution sometimes failed when file permissions or machine-access settings prevented the ADF run scripts to copy (fragment) files from one host to another. We have solved this by implementing in the code an automatic transfer of (file) data through the parallel message passing facility if the kid processes do not have the same file as the parent. This will cause a few seconds delay in the very early phase of the program, because parallel message passing of a fair amount of data is relatively slow. At the other hand, it has reduced the run-script-controlled copying of data files and makes the procedure more robust.

A serious slow-down of BAND in the final stage of the calculation, usually accompanied by one of more logfile messages 'BROKEN ELSTAT LOOP' (occurring during the processing of electrostatic interactions) has been cured.

The continuation code in the usage of block-type keys with arguments has been changed from the double plus character (++) to the ampersand (&). The old format is still supported, but not recommended.

User comments in the input file start with the exclamation mark (!) instead of the double colon ( :: ). The old format is still supported. The exclamation mark is recommended.