[CP2K-user] Large difference in lattice constant between CP2K and VASP

[ASSIDUO Network]

Hi there, I am trying to calculate the lattice constant of bulk Au using 
CP2K (cell optimization is fine). I have included my input file below.

With CP2K, I get a lattice constant around 4.6 Å, while with VASP I get a 
value of 4.17 Å. The literature lattice constant for bulk Au should be 
around 4.08 Å. Why do I get such a massive difference in value between CP2K 
and VASP/literature?

What would you advise I do with my calculation to improve my results? The 
largest basis set available for Au (with CP2K) is TZV2P. My supervisor 
wants me to use the GTH-PBE potential, so I can't change that.

Thank you for your help in advance :)
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20210118/8e9a0357/attachment.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: bulkAu.inp
Type: chemical/x-gamess-input
Size: 3805 bytes
Desc: not available
URL: <https://lists.cp2k.org/archives/cp2k-user/attachments/20210118/8e9a0357/attachment.inp>