In order to perform a complete SCF calculation, two types of scripts are provided on the distribution. For non-spinpolarized calculations use: run_lapw, for spin-polarized calculations use: runsp_lapw. Cases with/without inversion symmetry and with/without semicore or core states are handled automatically by these scripts. All activities of these scripts are logged in short in :log (appended) and in detail together with convergence information in case.dayfile (overwriting the old ``dayfile``). You can always get help on its usage by invoking these scripts with the -h flag.
run_lapw -h
PROGRAM: /zeus/lapw/WIEN97/bin_7/run_lapw PURPOSE: running the nonmagnetic scf-cycle in WIEN to be called within the case-subdirectory has to be located in WIEN-executable directory USAGE: run_lapw [OPTIONS] [FLAGS] OPTIONS: -cc LIMIT -> charge convercence LIMIT (0.0000) -ec LIMIT -> energy convercence LIMIT (0.0001 Ry) -fc LIMIT -> force convercence LIMIT (0 mRy/a.u.) -e PROGRAM -> exit after PROGRAM () -i NUMBER -> max. NUMBER (20) of iterations -s PROGRAM -> start with PROGRAM () -r NUMBER -> restart after NUMBER (20) iterations (rm *.broyd*) -nohns NUMBER ->do not use HNS for NUMBER iterations FLAGS: -h/-H -> help -I -> with initialization of in2-files to "TOT" -p -> run k-points in parallel (needs .machine file [speed:name]) -so -> run SCF including spin-orbit coupling -it -> use iterative diagonalization after first cycle -it0 -> use iterative diagonalization (also in first cycle) CONTROL FILES: .stop stop after SCF cycle .fulldiag force full diagonalization ENVIRONMENT VARIBLES: SCRATCH directory where vectors and help files should go
Calling run_lapw (after init_lapw) from the
subdirectory case will perform up to 20 iterations (or whatever
you specify with switch -i) unless convergence has been reached
earlier. You can choose from three convergence criteria, -ec
(the total energy convergence is the default and is set to 0.0001 Ry),
-fc (magnitude of force convergence) or -cc (charge convergence), but
only one criterium can be specified. Be careful with these criteria,
different systems will require quite different limits (e.g. fcc Li can
be converged to Ry,
only to
0.1 mRy). With -e PROGRAM you can run only part of one scf
cycle (e.g. run lapw0, lapw1 and lapw2), with -s PROGRAM you can start
at an arbitrary point in the scf cycle (e.g. after a previous cycle
has crashed and you want to continue after fixing the problem) and
continue to self-consistency. Before mixer is invoked,
case.clmsum is copied to case.clmsum_old, and the final
``important`` files of the scf calculation are case.clmsum and
case.scf.
Invoking
run_lapw -I -i 30 -fc 0.5
will first set in case.in2 the TOT-switch (if FOR was set) to save cpu time, then run up to 30 scf cycles till the force criterion of 0.5 mRy/a.u. is met (for 3 consecutive iterations). Then the calculation of all terms of the forces is activated (setting FOR in case.in2) for a final iteration.
Parallelisation is described in Sec. 5.4.
iterative diagonalization, which can save computer time in cases with ``few electrons'' and ``large matrices'', is described in Sec. 7.2. It needs the case.vector file from the previous scf-iteration and this file is copied to case.vector_old when the -it switch is set.
You can save computer time by performing the first scf-cycles without calculating the non-spherical matrix elements in lapw1. This option can be set for N iterations with the -nohns N switch.
For magnetic systems which are difficult to converge you can use the script runfsm_lapw (see section 4.5.3) for the execution of fixed-spin moment (FSM) calculations.
end:run_lapw