A Simple RHF Calculation on Hydrogen using New HFSolver

As of version 1.6, the syntax has been greatly simplified using the HFSolver module:

>>> from PyQuante import Molecule, SCF
>>> h2 = Molecule('h2',[(1,(0,0,0)),(1,(1.4,0,0))])
>>> solver = SCF(h2,method="HF")
>>> solver.iterate()
>>> print "HF Result = ",solver.energy


With the new solvers, you can run with an alternate basis set (say, STO-3G), via

>>> solver = SCF(h2,method="HF",basis="sto-3g")
>>> solver.iterate()
>>> print "HF Result = ",solver.energy


At this geometry (R=1.4 bohr) this should produce an energy of -1.1313 hartrees. Note that you may also import Molecule and HFSolver directly from the PyQuante namespace now.