ORCA

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The program ORCA is a modern electronic structure program package written by F. Neese, with contributions from U. Becker, D. Ganiouchine, S. Koßmann, T. Petrenko, C. Riplinger and F. Wennmohs. The binaries of ORCA are available free of charge for academic users for a variety of platforms.

ORCA is a flexible, efficient and easy-to-use general purpose tool for quantum chemistry with specific emphasis on spectroscopic properties of open-shell molecules. It features a wide variety of standard quantum chemical methods ranging from semiempirical methods to DFT to single- and multireference correlated ab initio methods. It can also treat environmental and relativistic effects.

How to submit calculations

Hi, finally orca is installed and working in kimik2. To send parallel calculations you must indicate the number of desired processors your input file:

       ...
       !     PAL4
       ...

(see page 23 of the manual, in the software repository http://aliga.iciq.es/fsn)

How to submit calculations:

       qs orcaVERSION.QUEUE NMACHINES INPUTNAME.in

where:

       VERSION can be 27 (for version 2.7) or 28 (for version 2.8)
       QUEUE can be cq4m4, c4m8, c8m24 or c12m24
       NMACHINES is the number of the machines to use (this parameter is related to the number of processors PALX in the input file)
       INPUTNAME is the name of your input

Input files

Single Point Dispersion Calculation Orca_disp.in

Pay attention!

Pay attention to the fact that it starts counting the atom in the coordinates from 0. I. e. In these coordinates:

C  0.000000    0.000000   -1.550099
Br 0.000000    0.000000    0.426228
H  0.000000    1.038299   -1.872463
H  0.899193   -0.519149   -1.872463
H -0.899193   -0.519149   -1.872463

C will be the atom 0, Br the atom 1, and the H the atoms 2, 3 and 4.

The same attends for the numbering of the orbitals.

Useful things

RIJCOSX with B3LYP:

! B3LYP RIJCOSX TZVP TZV/J Grid4 GridX4 NoFinalGrid TightSCF Opt

.....................................

RI-DFT with B3LYP & VDW corrections:

! B3LYP VDW RIJCOSX TZVP TZV/J Grid4 GridX4 NoFinalGrid TightSCF Opt

Note: You can choose which version of VDW corrections you need,

VDW06 (i.e. Grimme's paper from 2006)

VDW10 (the latest version that is implemented in ORCA).

If you just specify VDW, then the program will use the latest available version by default.

Note: B2PLYP-D means "B2PLYP VDW"

Eg:

! RI-B2PLYP VDW def2-TZVPP def2-TZVPP/C Grid4 NoFinalGrid VeryTightSCF

! RI-mPW2PLYP VDW def2-TZVPP def2-TZVPP/C Grid4 NoFinalGrid VeryTightSCF

.....................................

SCS-MP2:

! RI-SCS-MP2 def2-TZVPP def2-TZVPP/C VeryTightSCF Opt

Note: You could use it with RI because this is much faster

.....................................

CCSD(T):

! CCSD(T) cc-pVTZ VeryTightSCF and you can add more memory if needed only with %maxcore 2000

Note: CCSD(T) optimizations are not possible, but only single point energy calculations.

Manuals

Manual: http://www.thch.uni-bonn.de/tc/orca/index.php?option=com_docman&task=doc_download&gid=24&Itemid=26

Jump-start guide: http://www.thch.uni-bonn.de/tc/orca/index.php?option=com_docman&task=doc_download&gid=25&Itemid=26

Examples: http://www.thch.uni-bonn.de/tc/orca/index.php?option=com_docman&task=doc_download&gid=26&Itemid=26

links

http://www.thch.uni-bonn.de/tc/orca/