QMC

[Michael Towler <mdt26' at \`phy.cam.ac.uk>]

 Dear all,
 Quantum chemistry problem from a physics lab:
 I/we are looking for a package to generate ground and excited state wave
 functions for molecules to be used as trial wave functions in our quantum
 Monte Carlo code (extending our previous work on solids). Such a package
 needs to have the the following capabilities:
 (1) HF/DFT/CIS (CIS being the tricky but essential one to find).
 (2) Freeform input pseudopotentials. We have very specific pseudos
 tabulated on a grid for use in our QMC program. These neeed to be expanded
 in a basis set of Gaussians times powers of r for use in quantum chemistry
 packages. Because we need very accurate expansions, we require as few
 restrictions as possible on (a) the range of powers of r and (b) on the
 maximum number of basis functions in the expansion.
 (3) It needs to be fast and available for parallel platforms. In the
 latter case we have access to a Hitachi SR2201, a 64 CPU (R12000) SGI
 Origin 2000 and a Cray T3E. We need to do some very big CIS calculations
 which are beyond the reach of workstations.
 (4) not outrageously expensive ($$)
 (5) clearly documented output for conversion into format appropriate for
 hungry QMC code.
 Accessible source code would also be nice, but I guess we can do without
 it.
 We've been using Gaussian94 to do the above up to now, but it has severe
 limitations in the area of general ECPs i.e. acknowledged bugs and/or
 array size limitations which prevent us expanding the pseudos sufficiently
 accurately.. Gaussian98 appears to have corrected these problems to some
 extent but for reasons of either non-existence or lack of money it is not
 available on the parallel machines accessible to us. I don't mean any of
 the above as a criticism of the otherwise lovely Gaussian package - but
 these are genuine problems that I can't see a practical way around at the
 moment.
 I'll summarize any replies.
 Thanks,
 Mike
 PS: If anyone has a piece of code to perform an expansion of an arbitrary
 pseudopotential in a basis of gaussians times powers of r, and is prepared
 to share its secrets with me, I'd be interested to compare it with my own
 attempt.. ;-)
 -------------------------------------------------------------------------
 Dr. Mike Towler (mdt26' at \`phy.cam.ac.uk) Theory of Condensed Matter (Rm 524)
   Cavendish Laboratory, University of Cambridge, Cambridge  CB3 0HE, UK
 Tel. +44-(0)1223-337459                           Fax. +44-(0)1223-337356
 ----------------WWW: http://www.tcm.phy.cam.ac.uk/~mdt26/ ---------------