Paper: A. I. Boothroyd, W. J. Keogh, P. G. Martin, and M. R. Peterson 1996, "A Refined H3 Potential Energy Surface", J. Chem. Phys., 104, 7139-7152; gzip'd tar-file (133 kb, expands to 448 kb), including ascii abstract, postscript manuscript, plain TeX text, and a subdirectory with 14 Postscript figures.

• H3 Fortran program:
  • the text file h3progREADME.txt (4 kb) describing the BKMP2 H3 surface Fortran routines and test program,
  • the Fortran routines bkmp2.f (63 kb) for the BKMP2 H3 surface,
  • the Fortran test program bkmp2test.f (8 kb) to check that the surface is being evaluated correctly on your computer,
  • and the text file bkmp2test.out (3 kb) containing the correct output from the test program.
  • Alternatively, the gzip'd tar-file h3prog.tar.gz (21 kb; expands to 80 kb) contains all four of the above files.
  • NOTE that versions of these obtained prior to 29 October 1999 may be less accurate, since some of the required constants were not made explicitly double precision until then. (This only affects some compilers, but can cause the test program to yield incorrect output.) Note that it is O.K. if the test numerical derivatives disagree in the last few decimal places, but the rest of the output should be identical.
• H3 ab initio data:
  • the text file h3ptsREADME.txt (18 kb) describing the two available archives of H3 energies,
  • the gzip'd tar-file cih3usen.tar.gz (0.32 Mb; expands to 1.4 Mb) containing all the energies used to fit the BKMP2 H3 surface. Contains 5 files of ground-state ab initio energies, 2 files of non-ab-initio energies that were generated to constrain the surface at short and long range, and the README file above that describes the contents of this archive.
  • the gzip'd tar-file cih3ean.tar.gz (1.0 Mb; expands to 5 Mb) containing all the ab initio H3 energies computed by the above authors. Contains 5 files of ab initio energies, including some excited state energies, plus the README file above that describes the contents of this archive.
• The above surface and data supersede the old (Fortran) BKMP potential energy surface for H3 h3bkmpsurf.f (55 kb) (includes a short driver program; note that this version has not been updated to have explicitly double precision constants): from A. I. Boothroyd, W. J. Keogh, P. G. Martin, and M. R. Peterson 1991, "An Improved H3 Potential Energy Surface", J.Chem.Phys, 95, 4343-4359.

  Follow this link to the H4 surface.

  Home page of P. G. Martin.