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Fig. 11.4 Spectroscopic metaworkflow after dissection into subworkflows
subunits, which are repeated in other workflows. These subunits themselves rep-
resent small WS-PGRADE workflows. Especially for the investigation of quantum
chemical questions (Sect.
11.4.1
), the reusage of de
ned subworkflows is practical.
In Fig.
11.4
, a typical metaworkflow is shown: the whole workflow consists of
ve
subworkflows, which can be combined with other workflows to new metawork-
flows. This modular design is highly valuable for e-scientists, who prefer flexibility
and interoperability. The metaworkflows as well as the subworkflows can be stored
in the MoSGrid repository and the SHIWA repository. Currently, the MoSGrid
11.4.1 Quantum Chemistry
Quantum chemical (QC) simulations deal with the electronic structure of molecules.
An important task in quantum chemistry is the evaluation of the ef
ciency in
describing real molecular structures. Hence, lots of effort has focused on bench-
marking studies with variations of functional and basis sets sometimes in combina-
tion with solvent models. In a rather simple workflow, a given geometry can be
calculated with a given set of functions and basis sets. The key geometric parameters
are parsed and collected in tables afterwards. Further postprocessing can cover the
addition of a solvent model (Solv WF), calculation of natural bonding orbitals (NBO)
charges (NBO1 and NBO2 WFs) and frequencies (Freq1 and Freq2 WFs), formatting
of checkpoint
files for subsequent time-dependent
Density Functional Theory (DFT) calculations (Fig.
11.4
).
QC workflows were primarily implemented in MoSGrid for Gaussian (Frisch
2004) and NWChem (Valiev 2010). Both codes are used by new and experienced
users. Aiming at the inexperienced users, MoSGrid provides in the QC portlet
files and de
nition of new job
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