[Wien] RAM issues in lapw1 -bands

[Coriolan TIUSAN]

Dear wien2k users,

I am running wien 18.2 on Ubuntu 18.04 , installed on a HP station: 
64GB,  Intel® Xeon(R) Gold 5118 CPU @ 2.30GHz × 48.

The fortran compiler/math library are ifc and intel mkl library. For 
parallel execution I have MPI+SCALAPACK, FFTW.

For parallel execution  (-p options +.machines), I have dimensioned 
NMATMAX/NUME according to user guide. Therefore, standard calculations 
in SCF loops turn well, without any memory paging issues, about 90% of 
physical RAM being used.

However, in supercells, once getting case.vector files,  when 
calculating bands (lapw1c -bands  -p) with fine k structure (e.g. above 
150-200k on line X-G-X), necessary because I am looking to small Rashba 
shifts at metel-insulator interfaces...all available physical memory 
plus a huge amount of swap (>100G) are filled/used...

Any suggestion/ideea for overcoming this issue...without adding 
additional RAM?

Why in lapw1 -p for selfonsistance memory looks enough while with switch 
-band overload memory?

With thanks in advance,

C. Tiusan