charges are computed in real space only in spheres around the atoms and
these patches are added to rho on the dense fft grid.
Affected routines: addusdens and newd.
Should scale linearly with system size, as opposed to the quadratic
scaling of the G-space implentation.
Experimental version:
- no forces nor stress yet.
- parallel version to be tested
- not to mention phonon and the other codes ...
DISCLAIMER
There are accuracy issues to be understood better, we may need properly
modifies pseudopotentials in order to avoid (or reduce) errors when
ecutrho is still insufficient to describe all Fourier components of the
augmentation charge.
In this case (that is nearly always) also the usal G-space has errors
(negative charges for molecules and surfaces, for instance) but they are
usually small and we are used to live with them.
Some experience is needed to understand the relevance of the error related
to R-space augmentation charges.
CP has R-space augmentation with small-boxes.
They also produce some different, usually small, errors.
I think (I may be wrong) this is the origin of the fact that sometime PWscf
and CP total energies are not exactly the same.
SdG and Antonio Suriano
git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@2531 c92efa57-630b-4861-b058-cf58834340f0
correct place (kinds); module "varie" replaced by "control_flags" (not
yet in pwcom, though) - many many files changed.
64-bit cpus (Opteron, maybe Itanium) should now work if __LINUX64 is defined
git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@513 c92efa57-630b-4861-b058-cf58834340f0
- module filnam in pwcom moved to io_files module
- module units in pwcom moved to io_file
From now on, all file names and their unit and attributes (i.e. reclen)
should be defined in Modules/io_files.f90
git-svn-id: http://qeforge.qe-forge.org/svn/q-e/trunk/espresso@382 c92efa57-630b-4861-b058-cf58834340f0
sbraccia