A `Quick and Dirty' Tutorial

All TURBOMOLE modules need the control file as input file. The control file provides directly or by cross references the information necessary for all kinds of runs and tasks (see Section 15). define provides step by step the control file: Coordinates, atomic attributes (e.g. basis sets), MO start vectors and keywords specific for the desired method of calculation. We recommend generating a set of Cartesian coordinates for the desired molecule using special molecular design software and converting this set into TURBOMOLE format (see Section 16.2) as input for define.

A straightforward way to perform a TURBOMOLE calculation from scratch is as follows:

• generate your atomic coordinates by any tool or program you are familiar with,
• save it as an .xyz file which is a standard output format of all programs, or use a conversion tool like babel,
• use the TURBOMOLE script x2t to convert your .xyz file to the TURBOMOLE coord file:
  x2t xyzinputfile > coord
• call define; after specifying the title, you get the coord menu--
  just enter a coord to read in the coordinates.
  Use desy to let define determine the point group automatically.
  If you want to do geometry optimizations, we recommend to use generalized internal coordinates; ired generates them automatically.
• you may then go through the menus without doing anything: just press <Enter>, * or q--whatever ends the menu, or by confirming the proposed decision of define again by just pressing <Enter>.
  This way you get the necessary specifications for a (SCF-based) run with SV(P) as the default basis set which is roughly 6-31G*.
• for more accurate SCF or DFT calculations choose larger basis sets, e.g. TZVP by entering b all def-TZVP or b all def2-TZVP in the basis set menu.
• ECPs which include (scalar) relativistic corrections are automatically used beyond Kr.
• an initial guess for MOs and occupation numbers is provided by eht
• for DFT you have to enter dft in the last menu and then enter on
• for efficient DFT calculations you best choose the RI approximation by entering ri and providing roughly 3/4 of the memory (with m number; number in MB) your computer has available. (Auxiliary basis sets are provided automatically) In the printout of an ridft run you can check how much is really needed; a top statement will tell you if you overplayed your cards.
• B-P86 is the default functional. It has a good and stable performance throughout the periodic system.
• for an HF or DFT run without RI, you simply enter:
  [nohup] dscf > dscf.out &
  or, for a RI-DFT run:
  [nohup] ridft > ridft.out &
• for a gradient run, you simply enter:
  [nohup] grad > grad.out &
  or
  [nohup] rdgrad > rdgrad.out &
• for a geometry optimization simply call jobex:
  for a standard SCF input:
  [nohup] jobex &
  for a standard RI-DFT input:
  [nohup] jobex -ri &
• many features, such as NMR chemical shifts on SCF and DFT level, do not require further modifications of the input, just call e.g. mpshift after the appropriate energy calculation (mpshift runs with SCF or DFT using a hybrid-functional need a file size of the semi-direct file twoint that is non-zero).
• other features, such as post-SCF methods need further action on the input, using either the last menu of define where one can activate all settings needed for DFT, TDDFT, MP2, CC2, etc. calculations (this is the recommended way), or tools like Mp2prep or Rimp2prep. Please refer to the following pages of this documentation.