I am trying to perform NBO analysis with relaxed density matrix with the open-source program JANPA. I am following the guide here. The first step is to get the NBO input .47 file from Orca v4.2.1. The guide says that I should request NBO analysis with Orca in absence of the actual NBO executable to get the .47 file.

So I set the GENEXE and NBOEXE environment variables to dummy exe files that don't do anything when called. However, in spite of this, I cannot see the .47 file anywhere on the disk.

How do I generate the file required for NBO analysis? Any help is appreciated.

Edit: The input file I am using is:

! RHF SP def2-SVP NPA 

* xyz 0 1
   C       -1.54056        0.93336        0.00000
   H       -0.47056        0.93336        0.00000
   H       -1.89722       -0.02889       -0.30294
   H       -1.89722        1.67683       -0.68186
   H       -1.89723        1.15213        0.98480

I am setting the environment variables with

set GENEXE=C:\Users\Public\Orca4.1\orca\gennbo.exe
set NBOEXE=C:\Users\Public\Orca4.1\orca\nbo6.exe

Both nbo6.exe and gennbo.exe are dummy executables that don't do anything when executed. Note that the Orca version is 4.2.1 even though the directory name is 4.1.

  • 2
    $\begingroup$ Can we see the input file you are using? You don't even necessarily have to include the geometry, just the keywords for the calculation. Also, your tutorial and the ORCA manual suggest its behavior with NBOs differs by version, so you should include the version of ORCA you are using. $\endgroup$
    – Tyberius
    Feb 12, 2021 at 21:44
  • 1
    $\begingroup$ @Tyberius Added input file and orca version. $\endgroup$
    – S R Maiti
    Feb 12, 2021 at 22:24

1 Answer 1


All files are always created in the run directory where ORCA runs. I specifically did not want to deal with environment variables and path names and all that. Hope that helps! best wishes, Frank Neese

  • $\begingroup$ Thanks!! I never expected the author of Orca himself to answer, this is quite helpful. I am running orca with orca.exe input.inp > output.out, but I can't see any .47 file being created in the directory. Is there any command line arguments that I need? $\endgroup$
    – S R Maiti
    Feb 16, 2021 at 11:21

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