General input to DALTON : **DALTON INPUT

 

This input module describes the overall type of calculation that is to be done, and also which of the four programs that DALTON consists of, that is to be executed. It also contains two submodules describing the performance of parallel calculations and the geometry optimization routines. We note that this input module has to start all input files for DALTON .

.DIRECT  

The calculation is to be done in a direct manner , that is, the two-electron integrals  are to be constructed ``on the fly'' and not written to disc as is the default. This keyword will only work for SCF    wave functions, and two-electron integrals (and differentiated two-electron integrals) will not be written to disc in any part of the calculation.

.INPTES  

Test the input of the **GENERAL   input module. The program will abort after the completion of the input test, and no calculation will be executed.

.INTEGRALS  

Invoke the HERMIT  program for generating molecular one- and two-electron integrals. See Chapter   .

.ITERAT  

READ (LUCMD, '(I5)') ITERNR

Tells the program at which iteration to start the geometry optimization . Note that this will not affect which molecule input file that is going to be read, as this have to be handled by the shell script . It only determines what number the output of the predicted molecular geometry will be.

.MAX IT  

READ (LUCMD, '(I5)') ITERMX

Change the maximum number of geometry iterations   that can be done. Default is 20. This number has to be increased in Intrinsic Reaction Coordinate (IRC)   or dynamical trajectory studies , as these usually require a much larger number of iterations.

.OPTIMI  

Do a geometry walk . If no input is given in the *WALK   input submodule, an optimization of the molecular geometry  to a stationary point with no negative Hessian eigenvalues  (a local minimum) will be done. However, this may changed be appropriate keywords in the submodule *WALK  , and we refer to examples in the chapter on potential energy surfaces (Chapter ), and subsection  describing the input cards for the *WALK   submodule for a more detailed description of possible options.

.PARALL  

Denotes that the calculation of two-electron integrals  are to be done in parallel . This also implies that the calculation is done without writing two-electron integrals to disc. This keyword only applies to SCF    wave functions, but all two-electron integral evaluations in an SCF calculation will be done parallel. More details about the parallelization strategy in DALTON can be found elsewhere [53].

The keyword requires that the program has been installed and compiled with the appropriate preprocessor directives for an MPI installation , or the construction of a slave program for the PVM installation .

If MPI  is used as message passing  interface, no further keywords are needed, as the number of nodes will be set equal to the number of nodes asked for when submitting the job. However, if PVM  is used as message passing interface, the number of nodes needs to be given in the *PARALL   submodule input, and this number have to be equal to the number of nodes asked for when submitting the job. Note also that in order to evaluate the parallelization efficiency , a print level of at least 2 is needed in the *PARALL   submodule.

.PRESORT  

  Requests that the two-electron integrals should be sorted and that the integral transformation routines of Bjørn Roos should be used during execution of the program. This will only work on 32-bit architectures, but is needed in order to be able to run with more than 255 basis functions.

.PRINT  

READ (LUCMD, *) IPRUSR   Reads in the print level that is to be used the rest of the subsequent calculations. Default is a print level of 0.

.PROPERTIES  

Invoke the ABACUS  program for the evaluation of static and dynamic properties. See Chapter .

.RESPONSE  

Invoke the RESPONSE  program for the evaluation of static and dynamic properties. See Chapter .

.RUN ALL  

Invoke all the programs HERMIT  , SIRIUS  , RESPONSE  , and ABACUS  for a single point calculation.

.RUN PROPERTIES  

Invoke the programs HERMIT  , SIRIUS  , and ABACUS  for a single point calculation.

.RUN RESPONSE  

Invoke all the programs HERMIT  , SIRIUS  , and RESPONSE  for a single point calculation.

.TOTSYM  

Consider only totally symmetric perturbations . This option only affects geometric perturbations and static electric-field perturbations requested through the keyword .POLARI  .

.WAVE FUNCTIONS  

Invoke the SIRIUS  program for the evaluation of SCF, MP2, and MCSCF wave functions      . See Chapter .

• End of General input: *END OF
• General: *MINIMIZE
• Parallel calculations : *PARALL
• Geometry optimization: *WALK