CASINO manual - Theory of Condensed Matter

• Eigenvalue spectrum (used to work out which orbitals to occupy and, crudely, whether the
system is a metal or an insulator);
• The output file from the program that generated the trial wave function (not read by casino—
for reference only).
These files are generated automatically by various utilities available for different electronic structure
programs (see Secs. 8 and 9). The format of the different files should be clear from looking at the
various examples for different dimensionalities and basis sets.
If correlated sampling is introduced into casino, it may be necessary to define several xwfn.data
files. These will be named xwfn.data.1, xwfn.data.2, xwfn.data.3, . . .
7.8.1 gwfn.data file specification
The gwfn.data file contains orbitals expanded in a Gaussian basis set. The original specification is
below, followed by an actual example:
Dimensions of allocated arrays are shown.
For the larger fields I use the following formatting.
% strings (title,code,method,functional) may be up to 80 characters long.
* free format
$ FORMAT(3(1PE20.13)) - for reals naturally grouped in triples (e.g. coords)
& FORMAT(4(1PE20.13)) - other reals (e.g. gaussian exponents)
@ FORMAT(8I10) - lengthy lists of integers
use e.g. write(IO,format=&)(array(i),i=1,size)
First line of file is TITLE field.
MDT 1997
------------------------------------------------------------------------------
% TITLE (the title)
BASIC INFO
----------
% CODE:
name of code producing this file
(i.e. CRYSTAL95/98/03/06/09 GAUSSIAN94/98/03/09, TURBOMOLE)
% METHOD:
Comment - RHF/ROHF/UHF/DFT/S-DFT/CI/etc.
% FUNCTIONAL
DFT functional name. If method not DFT then ‘none’.
* PERIODICITY:
system dimension 0,1,2,3 => molecule, polymer, slab, solid
* SPIN_UNRESTRICTED:
.true. or .false. (i.e. different orbitals for different spins)
* EIONION:
nuclear-nuclear repulsion energy (au/atom)
* NUM_ELECTRONS:
number of electrons per primitive cell
GEOMETRY
--------
* NUM_ATOMS:
number of atoms per primitive cell
$ BASIS(3,NUM_ATOMS):
atomic positions(au)
@ ATNO(NUM_ATOMS):
atomic numbers for each atom
& VALENCE_CHARGE(NUM_ATOMS):
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