CASINO manual - Theory of Condensed Matter

Note that this facility only exists in the official version of crystal03 in binaries produced after
December 2003, and that some early versions of crystal03 had a broken pseudopotential evaluator
(which should now be fixed).
The crystal run script included with casino will actually force the production of gwfn.data automatically
if you invoke it with the -qmc flag when running the calculations, so all you need to do is
type run -qmc input filename. If the calculation is periodic, the script will ask you how many different
supercell sizes N you wish to generate, and then to input N sets of integer triplets indicating the
supercell sizes (these must be a subset of the MP shrinking factors in the crystal input file). For
example,
% run -qmc h
Number of different QMC supercell sizes to calculate? (Maximum 5)
% 1
Size of cell 1? (e.g., 2 2 2)
% 2 2 2
Put the script in the background with ‘Ctrl-Z’ then ‘bg’.
If you want to do this by hand, rather than letting the run script do it for you, then the relevant part
of the crystal properties input file looks like this (for periodic systems):
QMC
2 ! want to generate 2 supercell sizes i.e.
2 2 2 ! a 2x2x2 one
3 3 3 ! and a 3x3x3 one
END
For molecules, only the keyword ‘QMC’ is required with no additional input.
8.4.4 Generating gwfn.data files with CRYSTAL06/09
Note this is only possible with versions of crystal06 from 1 0 2 onwards, since the 1 0 1 version does
not recognize the required CRYAPI OUT keyword.
The entire process is automated by running crystal06/09 with the supplied script runcrystal. If you
choose to do this, then simply typing runcrystal -qmc input filename will run the SCF calculation
as normal then invoke all the necessary post-processing to generate the gwfn.data file automatically.
The crystal09 version is run by default; crystal06 may be selected using the -06 flag.
The only complication is in periodic systems where, before executing the crystal code, the run script
will ask you how many different supercell sizes you require. You then need to input that many integer
triplets (divisors of the crystal ‘shrinking factors’) to specify the size of each of the supercells. A
gwfn.data file will then be generated for each required cell (appropriately labelled with the integer
triplet—rename them before running with casino).
Running the gwfn.data generation procedure manually
If you choose to run crystal06/09 without our runcrystal script (say, with the scripts provided by
the Torino people) then you will need to carry out the following manual procedure to generate the
gwfn.data file(s).
Note that runcrystal is an old csh script that does not support the CASINO archicture system
(like, e.g., runqmc, runpwscf, runlouis). It is hoped that a modernized bash version which does this
might appear in the future.
Molecules
After completing a converged DFT/HF run with the crystal06/09 crystal binary, the properties
program needs to be run to produce the formatted data files needed by the casino crysgen06/09
utilities. A minimal input file for the properties program in the case of a nonperiodic system is:
NEWK
1 0
CRYAPI_OUT
END
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