Hi,

I'm trying to compute the 119Sn chemical shift tensors and I'm encoutering the following error during the calculation of NMR parameters using CASTEP:

Error: magres_nmr_current_crys: diagonalise hamiltonian at qpt not converged

Current trace stack:

magres_nmr_current_crystal

magres_nmr_calculate

magres_run

castep

The calculation then exits without any output in the  _NMR.magres file. I'm using the GGA (PBE) functional and on-the-fly for pseudopotentials. I tried to run the Energy task at Fine quality settings and Ultrafine, with the same outcome. I also tried to run either with and without checking the Metal checkbox, but the error persisted.

What does this message mean?? What could cause this error and how can it be prevented?

I'm very curious to hear your answers!!!

Best regards,

Jean-Philippe Demers