Revised and extended MMFF94 Validation Suite

 Dear CCLers,
 Jan Labanowski has kindly posted on the Computational Chemistry List
 archives a revised and extended version of the MMFF94 Validation Suite that
 was first released in May 1998. The new suite corrects MMFF94 results for
 eight
 structures for which the atom typing has been found to be erroneous, and adds
 eight additional structures geared to more fully test the empirical-rule
 parameter generation procedures defined in the published MMFF94 papers.
 The suite contains a README file (or, for Web browsers, its html equivalent)
 that defines the files in the validation suite.  The most important are:
 MMFF94_dative.mol2 		mol2-format input, using dative bonds for
                                     		certain sulfur and
 phosphorous compounds
 MMFF94_hypervalent.mol2	SYBYL mol2 input, using "hypervalent"
 					representations
 MMFF94.mmd 			BatchMin/MacroModel dat-format input
 MMFF94.energies			list of BatchMin and Merck-OPTIMOL total
 					energies
 MMFF94_bmin.log			BatchMin output log file
 MMFF94_opti.log 			OPTIMOL output file with detailed
 					interaction analyses
 MMFF94.changed-or-new_results 	Energies for new structures and for
 						structures affected by corections to
 the
 						MMFF94 atom-typing procedures
 MMFF94.empirical_rule_parameters	Listing of structures and
 interactions for
 						which empirical-rule parameters are
 						generated
 These input and output files provide data for the validation suite, which
 now
 consists of 761 molecules.
 Also provided are auxiliary files that list the names of molecules that have
 alternative dative and hypervalent representations (MMFF94.dative_molecules);
 that specify the formal atomic charges used in the dative and hypervalent
 representations (MMFF94.fc_dative and MMFF94.fc_hypervalent); and that list
 the
 molecule names and titles (MMFF94.titles).
 Most of the input data is derived from CSD structures.  I wish to thank
 Steve Salisbury and the Cambridge Crystallographic Data Center for
 graciously consenting to the use of this data.  I also wish to thank Jan
 Labanowski for his encouragement in the posting of this validation suite and
 for his role in providing CCL and its archives to the community.
 My hope is that this data will assist members of the community who have
 independently implemented MMFF94, or who are in the process of doing so, to
 validate their efforts (I am aware of five such initiatives, in addition to
 the BatchMin and CHARMm implementations to which Merck has contributed).
 Those who have already implemented MMFF94 should obtain and compare results
 for
 the corrected and added members of the validation suite, and should insure
 that
 any modifications they need to make do not affect the other members of the
 suite.
 This validation suite is also intended allow individuals who use an
 independently developed commercial implementation of MMFF94 to carry out
 their
 own validation and to satisfy themselves as to its authenticity.
 Those who are not interested in pursuing MMFF94 per se might view the suite
 as a source of input data that could be useful in developing and testing
 other force fields. A force-field evaluation suite comprised of ab initio
 and/or experimental data on conformational energies and on intermolecular
 interactions together with input molecular structure data is being posted
 elsewhere on the CCL archives.  This suite may be even more useful for this
 purpose.
 The MMFF94 validation suite can be accessed at:
 ftp://www.ccl.net/pub/chemistry/data/MMFF94
 or at:
 http://www.ccl.net/cca/data/MMFF94
 I would be pleased to hear of any use made of this data.
                                                         Best regards,
                                                         Tom Halgren
                                                         voice: 732-594-7735
                                                         fax: 732-594-4224
                                                         halgren;at;merck.com