<div>Dear Cp2k developers,</div><div><br></div><div>just by coincidence I noticed that I get different electronic energies depending on the absolute coordinates of my input molecule.<br>I tried a simple test system with O2 in a 15x15x15x angstrom cube. I set-up 2 different xyz files, one with 3.xx angstrom in the z coordinates and one with 34.xx angstrom in the z coordinate. However, both O2 molecules are identical in their bond length, they are simply translated to each other.<br>As long as I center the coordinates, I get the identical electronic energy of<br>-31.929620495691506<br>But if I don't center the coordinates, I get different results:<br>-31.929366281248029 (inside)<br>-31.929298672694223 (outside)<img src="data:chemical/x-xyz;base64,MgoKTyAgICAgIDIuMzkzMDE5NDU1MCAgICAzLjAwOTU1NTY3ODcgICAzNC4wNTE2NTMwNDczCk8gICAgICAzLjYyNjU2NjAxMDEgICAgMy4wMDk1NTM3NDQyICAgMzQuMDUxNjQ1MjcyNAo=" alt=""><img src="data:chemical/x-xyz;base64,MgoKTyAgICAgIDIuMzkzMDE5NDU1MCAgICAzLjAwOTU1NTY3ODcgICAzLjA1MTY1MzA0NzMKTyAgICAgIDMuNjI2NTY2MDEwMSAgICAzLjAwOTU1Mzc0NDIgICAzLjA1MTY0NTI3MjQK" alt=""><img src="data:chemical/x-gamess-input;base64,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" alt=""><img src="data:chemical/x-gamess-input;base64,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" alt=""><img src="data:chemical/x-gamess-input;base64,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" alt=""><img src="data:chemical/x-gamess-input;base64,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" alt=""><br><br>I mean, I can imagine that it leads to difficulties, if the molecule is placed outside of the defined cell, but especially the different energy for the O2 molecules that is placed within the cell, albeit not the exact center, confuses me.<br><br>Am I doing something wrong here or is this expected behavior? If the latter is the case, why aren't all coordinates centered by default (which I guess I will do from now on)?<br><br>Input and systems see attachment.<br><br>Thanks in advance and best regards,</div><div>Miguel<br></div>