Re: CCL:QM/MM combined potential

 Dear Markus,
 The first reference I've seen on a real QM/MM calculation is from Warshel and
 Levitt J. Mol. Biol. vol 103, p 227 (1976).  Singh and Kollman published in
 J. Comp. Chem. vol. 7 p. 718 (1986).  Later, Field, Bash, and Karplus published
 two papers:  JACS vol 109, p 8092 (1987), and J. Comp. Chem. vol 11 p 700
 (1990).  The latter paper was a very systematic study that went far to
 making the use of these methods more general (though much still remains
 to be solved).  Jiali Gao has really pushed the method recently for
 solution-phase simulations (too many papers to cite)  have a look at Science
 vol. 258 p 631 (1992) and Biophysical Journal vol 65 p 43 (1993) and references
 therein.  Recently, Stanton et. al. have tried QM/MM involving DFT
 J. Phys. Chem. vol 97 p 11868 (1993).
 We have a paper (in press; J. Phys. Chem. due out in Oct)
 "The Nature of K+/Crown Ether Interactions:
 A Hybrid Quantum Mechanical-Molecular Mechanical Study"
 Thompson, Glendening, and Feller.
 As for software:
 1).  CHARMM has the Field,Bash, and Karplus stuff in it,
      though I'm not sure of its distribution status.
 2).  Jiali Gao has been using a BOSS/MOPAC fusion for his
      Monte Carlo studies.
 3).  Ken Merz (the Stanton reference) is using some variant
      of AMBER coupled with DeFT or DeMon, I believe.
 4).  (shameless plug) My own code Argus v. 3.0 has an
      extensive suite of QM/MM capabilities.  We can do
      solution chemistry of small solutes all the way to proteins.
      Calculation Types: Energy, Spectra (SCF/CI), Opt. Geom,
                         MD, Free Energies, SCRF
      Hamiltonians:      EHT, INDO1, INDO/s, MNDO, AM1, PM3,
                         limited ab initio, NDDO1, MM, and MMpol.
      System Types:      QM, MM, QM/MM
      To my knowledge, Argus is the only code designed from
      its inception to be able to describe chemical systems
      with multi-Hamiltonian methods (as opposed to merging
      pre-existing mature codes, often with highly dissimilar
      data models).  It's been very easy (for me) to modify
      and extend the code when we have new ideas to try out.
 There are many more references (too many to cite here), but
 the above should get you started.
 Best Regards,
 Mark Thompson
 Mark A. Thompson
 Sr. Research Scientist              email:  d3f012 (- at -)
 Molecular Science Research Center   FAX  :  509-375-6631
 Pacific Northwest Laboratory        voice:  509-375-6734
 PO Box 999, Mail Stop K1-96
 Richland, WA.  99352
 Dear all,
    I have heard of a method which combines a quantum
 mechanical and a molecular mechanical potential
 for molecular dynamics simulations. This method
 treats a reaction centre by quantum mechanics and
 the rest of the system is calculated by the force
 field method.
 My questions are:
 1. Does anyone know any references to this mehod?
 2. Is there any software available which can treat
    a system using this method?
 Thanks in advance.
                     Markus Haeberlein