The input is divided into modules, which in turn are further divided into submodules. The modules contain the input to the different sections that constitute the DALTON program package. There exists four such sections corresponding to respectively the integral evaluation, the choice of wave function, the choice of static properties and finally the choice of dynamic properties. For each of these sections there exists a module with a name started by two stars, that is:
In addition there is a module controlling the DALTON program, which has the input card **DALTON. All input modules will be described in detail in separate chapters in the Reference Manual.
For geometry optimizations,
different options may often be wanted for different stages of the
geometry optimization, and there exists three different ABACUS input
modules for geometry optimizations:
**START,
**EACH STEP,
**PROPERTIES.
**START gives input for the initial point,
**EACH STEP gives input options during the optimization of the
molecular geometry
(and for the initial point if no
**START was specified and for
the final point if no
**PROPERTIES was given),
and
**PROPERTIES gives input options for the
analysis that is to be done at the optimized geometry. In this way one
may start a calculation at an experimental geometry, evaluating a set
of molecular properties of interest, do an ordinary geometry
optimization without any properties evaluated during the geometry
optimization, and then recalculate the same set of molecular
properties (or others) at the optimized geometry in one single run.
Note that if a **RESPONSE module present in a geometry optimization,
the RESPONSE calculations will only be performed at the optimized geometry.
The input file must end with the keyword *END OF.
In a given module, several submodules may be specified, which determine the performance in various parts of the calculation. The different input cards available in the different submodules are started with a dot, i.e. an input option should be typed as .IMAGE. For most calculations the default settings may be used. The authors have, however, always opted for the largest degree of freedom, giving the user good opportunities for tailoring an input to suit the needs of a given calculation.
Even though we at times write large, self-explanatory keywords in this
manual, only the first seven characters (including the . or
*) are significant and will be
treated by the program. At any
place in the input, comments may be added using
# or !
in the first position of the command line. The input is case sensitive
and only upper-case characters will be recognized.
A general input structure for DALTON will look like
**DALTON INPUT ... **INTEGRALS ... **WAVE FUNCTIONS ... *CONFIGURATION INPUT ... **START ... **EACH STEP ... **PROPERTIES ... **RESPONSE *CUBIC ... **END OF DALTON INPUT
Several submodules can of course be added in each of the above modules. We restate that if RESPONSE is requested in a geometry optimization, the evaluation of the response functions will only be done at the optimized geometry.
Examples of input files can be found in the various chapters
describing the calculation of different molecular properties, and
these chapters will probably be sufficient for most calculations done
with DALTON. However, all possible keywords are described in detail
in separate chapters in the Reference Manual. The tests in the
dalton/test directory also serves to demonstrate how to run
different kinds of calculations using DALTON (see the
CONTENTS file in the test directory).