ERROR: could not open library file

Hi all,

I’m getting an Error when trying to load a simple single calculation file, this is the input:

3.83 3.83 3.711 90.000000 90.000000 90.0
Fe c 0.0 0.0 0.0
Fe c 0.5 0.5 0.0
Pt c 0.5 0.0 0.5
Pt c 0.0 0.5 0.5
library nodump mean_2nn
output cif fept_unitcell.cif

The mean_2nn file is in the same directory as the input file, and the gulp simulation software package. However, I keep getting this Error:

*                       GENERAL UTILITY LATTICE PROGRAM                        *
*                                 Julian Gale                                  *
*                       Curtin Institute for Computation                       *
*                    School of Molecular and Life Sciences                     *
*                    Curtin University, Western Australia                      *
* Version = 5.2.0 * Last modified =  30th August 2020                          *

!! ERROR : could not open library file = mean_2nn

I have tried changing the name of the folder to “meam_2nn.lib”, but that doesn’t work either, does anyone know how GULP actually searches for library files when it runs?

Thanks for any help!


Hi Connor,

I think you’ll find the problem is that the file is called “meam_2nn” rather than “mean_2nn” with a lib on the end. When I correct the typo the file is now found.

PS There is an error in the structure symmetry which causes 2 atoms to be on top of each other & so the energy becomes NaN

Wow, how embarrassing. :sweat_smile:

Thanks very much Julian, I noticed the second mistake actually, so now I have nosymmetry enabled. Is that the best way to deal with it? Or do you get more from the minimiser if you keep the symmetry on and remove one of the Pt atoms?


We’ve all been there & so no worries.

Because the system is so small the use of symmetry or not makes little difference since we’re talking fractions of a second in cost & the minimiser will work fine either way due to the high symmetry. Personally I’d leave the symmetry on though if possible.