General input to DALTON : **DALTON

This input module describes the overall type of calculation that is to be done. It also contains four submodules describing the performance of parallel calculations, the control of the two different geometry optimization routines, as well as control the general routines for calculating numerical geometrical derivatives of molecular energies or selected first- and second-order properties. 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, Density Functional Theory calculation and for coupled cluster (CC) calculations. In HF and DFT calculations the two-electron integrals (and differentiated two-electron integrals) will not be written to disc in any part of the calculation, whereas in the direct CC approach, the two-electron integrals will be stored in three general-indexed batches, thus requiring a loop over all basis functions for one of the two-electron integral indices [].

.DOUGLAS-KROLL

Include scalar relativistic effects by using the Douglas-Kroll transformed one-electron potential and kinetic energy Hamiltonian.

.INPTES

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

.INTEGRALS

Invoke the HERMIT and/or the ERI program for generating molecular one- and two-electron integrals. See Chapter 22 for the HERMIT and Section 22.2.8 ERI programs, respectively.

.ITERATION

READ (LUCMD, '(I5)') ITERNR

Tells the program at which iteration to start the geometry optimization using the **WALK module. Note that this will not affect which molecule input file that is going to be read, as this is handled by the job script dalton. It only determines what number the output of the predicted molecular geometry will be, as well as where to start writing information on the files containing information about an IRC calculation (DALTON.IRC) or a dynamical trajectory walk (DALTON.TRJ).

.MAX IT

READ (LUCMD, '(I5)') ITERMX

Change the maximum number of geometry iterations that can be done. Default is 20. For numerical differentiation/vibrational averaging, the number of iterations will be reset to $6N+1$ (where $N$ is the number of nuclei) as the number of required iterations for these calculations are well defined. This number has to be increased in Intrinsic Reaction Coordinate (IRC) or dynamical trajectory studies. However, changing this variable will override this reset option.

.OPTIMIZE

Do a geometry walk. If no input is given in the *OPTIMIZE input submodule, an optimization of the molecular geometry to a stationary point with no negative Hessian eigenvalues (a local minimum) will be done using the default first-order methods. However, this may be changed using appropriate keywords in the submodule *OPTIMIZE, and we refer to examples in the chapter on potential energy surfaces (Chapter 7), and subsection 21.1.3 describing the input cards for the *OPTIMIZE submodule for a more detailed description of possible options.

.NMDDRV

Calls for a generalized numerical geometry differentiation. These routines will take advantage of the full molecular point group in order to minimize the number of point to be calculated. What order of derivatives and whether any analytical derivatives are to be used is determined in the *NMDDRV input module.

.PARALLEL

Requests that the calculation of two-electron integrals is 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 and DFT calculations, but all two-electron integral evaluations in an SCF calculation will be done parallel as well as the integration of the exchange-correlation functionals and kernels. More details about the parallelization strategy in DALTON can be found in Ref. [90].

The keyword requires that the program has been installed and compiled with the appropriate preprocessor directives for an MPI installation. Note that in order to evaluate the parallelization efficiency, a print level of at least 2 is needed in the *PARALLEL submodule.

.PARNMD

Option non-functional. Do not use.

.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. The keyword is needed if one attempts an MCSCF, CI or MP2 (run through the SIRIUS module and not using the Coupled-Cluster module) with more than 255 basis functions.

.PRIERR

READ (LUCMD, *) IPRERR Reads in the print level that is to be used in the DALTON.ERR file. Default print level is IPRUSR+1.

.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 25.

.RESPONSE

Invoke the RESPONSE program for the evaluation of static and dynamic properties. See Chapter 26.

.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.

.RUN WAVE FUNCTIONS

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

.RUNERI

Force the use of the vectorized integral code ERI where possible.

.TOTSYM

Consider only totally symmetric perturbations. This option only affects geometric perturbations calculated using the second-order based .WALK option and static electric-field perturbations requested through the keyword .POLARI.

.VECLEN

READ(LUCMD,*) IVECLN

Set the number of Fock matrices to be used during Fock-matrix constructions in direct calculations. This function is only of interest for vector machines. The default is 128. The larger the number, the more memory will be required in the calculation.

.WALK

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 using a second-order method with analytical Hessians. However, this may be changed by appropriate keywords in the submodule *WALK, and we refer to examples in the chapter on potential energy surfaces (Chapter 7), and subsection 21.1.3 describing the input cards for the *WALK submodule for a more detailed description of possible options.

.WAVE FUNCTIONS

Invoke the SIRIUS program for the evaluation of SCF, MP2, Coupled Cluster and MCSCF wave functions as well as DFT calculations. See Chapter 24.