GFN0-xTB under PBC

[lcdamoy]

Hi, all, i used GFN0 and GFN1 to optimize the molecular crystal unders PBC with xtb code, i found that GFN0 will optimize the lattice constants in the meantime, while GFN1 will not. Both in the same configuration. Is there some measure to fix lattice constants?

[awvwgk]

The PBC implementation in xtb is somewhat unfinished at the moment. I'm currently integrating the xTB methods in the DFTB+ program package to allow using their periodic framework. With the DFTB+ 21.2 release the xTB Hamiltonian is now supported via the tblite library.

[zhangyue1723]

I use cp2k to perform xtb calculation the reason is also the changing of lattice parameter. But another question is, I should use the Tag of "Shake" to control the dissociation of H atom, but there seems no same control method in cp2k?