Last week I went to the annual Symposium on Theoretical Chemistry. This
time the 51th STC
took place from the 20th till the 24th of September in Potsdam.
Unlike last year, where the conference business was all new to me, this
year it was more like returning to a place with a familiar atmosphere
and many familiar faces. Whilst the conference surely was again a great
opportunity to present my work and to learn about theoretical chemistry
in the lectures, this time it had the additional aspect of catching up
with the people I already met last year. Most of all I enjoyed the
poster sessions this year, probably because of the many discussions I
had with other researchers and PhD students about their recent advances.
Concerning our project we still were not able to obtain noteworthy
results with our current implementation of finite-element Hartree-Fock
(see Poster attached below). This is mainly due to the extreme memory
requirements the calculation of the Hartree-Fock exchange matrix imposes
on the program: Right now we store this whole beast in memory and hence
get quadratic scaling with respect to the number of finite elements in
the amount of memory we require. In other words even for extremely small
test cases we need gigabytes of memory to achieve only very inadequate
accuracy.
Together with James
Avery,
who visited us for a few days in July, we recently managed to come up
with a new scheme for implementing Hartree-Fock exchange within the
finite-element method. This looks very promising, since it decreases
both the memory as well as the computational cost to linear scaling.
Right now we struggle with the implementation, however. In November I
will visit James in Kopenhagen for 3 weeks. If all goes well we will
hopefully overcome these problems and work out a good structure for a
FE-HF program, that incorporates everything we learned so far.
