Editing VASP-MGCM (solvation module) (section)

=== Finding the error ===


Often it requires a lot of 'trial-and-error' before you get your system to run. But there are some things to check in your output, which may give you a clue about what was going wrong:

* Check your error file (e-xxx, o-xxx files; slurm-xxx file in Marenostrum): 

- Did the electronic optimisation start and crash after the first electronic step, the reason is likely that your WAVECAR was erroneous or not well converged. 

- Did the electronic optimisation start and crash after the first NELMDL non self-consistent steps (default is 5), there is something wrong when adding the solvent. This may possible be solved with using a smaller EPSINF (not yet tried).

- Did the electronic optimisation not start at all, check if there is a memory-related error, such as 'insufficient virtual memory' or 'Out of memory'. This might be solved with reducing the cut-off energy.

Often this problem can be solved by using C24, instead of C28 or marenostrum nodes. At BSC or C28 several softwares are over-optimised, maybe the modules mkl or intel, which can lead to problems. C24 is generally more stable!

* Check the ERROR file: It gives you the relative error (ERROR RELATIU) when going step-wise from a large grid to small grid, as described in the MGCM algorithm. Usually the relative error should decrease, if it suddenly increases to a very high number, there might be an error in the grid partitioning, which have causes a division by zero. Check carefully that the grids in vacuum and in solvent are equal!

* Check the fort.71 file that gives you the grid partitions in real and reciprocal space. Check if they are the same for calcualations with and without solvent.

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